E33.03 - Sound Transmission

SIGNIFICANCE AND USE
5.1 Sound transmission loss as defined in Terminology C634, refers to the response of specimens exposed to a diffuse incident sound field, and this is the test condition approached by this laboratory test method. The test results are therefore most directly relevant to the performance of similar specimens exposed to similar sound fields. They provide, however, a useful general measure of performance for the variety of sound fields to which a partition or element may typically be exposed.  
5.2 In laboratories designed to satisfy the requirements of this test method, the intent is that only significant path for sound transmission between the rooms is through the test specimen. This is not generally the case in buildings where there are often many other paths for sounds—flanking sound transmission. Consequently sound ratings obtained using this test method do not relate directly to sound isolation in buildings; they represent an upper limit to what would be measured in a field test.  
5.3 This test method is not intended for field tests. Field tests shall be performed according to Test Method E336.
Note 2: The comparable quantity measured using Test Method E336 is called the apparent sound transmission loss because of the presence of flanking sound transmission.
SCOPE
1.1 This test method covers the laboratory measurement of airborne sound transmission loss of building partitions such as walls of all kinds, operable partitions, floor-ceiling assemblies, doors, windows, roofs, panels, and other space-dividing elements.  
1.2 Laboratories are designed so the test specimen constitutes the primary sound transmission path between the two test rooms and so approximately diffuse sound fields exist in the rooms.  
1.3 Laboratory Accreditation—The requirements for accrediting a laboratory for performing this test method are given in Annex A4.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 The main part of this standard uses procedures originally developed for laboratory measurements of the sound transmission loss of partitions. These procedures assume that the rooms in which the measurements are performed have a sound field that reasonably approximates a diffuse field. Sound pressure levels in such rooms are reasonably uniform throughout the room and average levels vary inversely with the logarithm of the room sound absorption. Not all rooms will satisfy these conditions. Experience and controlled studies (1)6 have shown that the test method is applicable to smaller spaces normally used for work or living, such as rooms in multi-family dwellings, hotel guest rooms, meeting rooms, and offices with volumes less than 150 m3. The measures appropriate for such spaces are NR, NNR, and ATL. The corresponding single number ratings are NIC, NNIC and ASTC. The ATL and ASTC are measurable between larger spaces that meet a limitation on absorption in the spaces to provide uniform sound distribution.  
5.2 Annex A1 was developed for use in spaces that are very large (volume of 150 m3 or greater). Sound pressure levels during testing vary markedly across large rooms so that the degree of isolation varies strongly with distance from the common (separating) partition. This procedure evaluates the isolation observed near the partition. The appropriate measure is NR, and the appropriate single number rating is NIC.  
5.3 Several metrics are available for specific uses. Some evaluate the overall sound isolation between spaces including the effect of absorption in the receiving space and some evaluate the performance or apparent performance of the partition being evaluated. The results obtained are applicable only to the specific location tested.  
5.3.1 Noise Reduction (NR) and Noise Isolation Class (NIC)—Describe the sound isolation found between two spaces. Noise reduction data are based on the space- and time averaged sound pressure levels meeting the require...
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1.1 The sound isolation between two spaces in a building is influenced most strongly by a combination of the direct transmission through the nominally separating building element (as normally measured in a laboratory) and any transmission along a number of indirect paths, referred to as flanking paths. Fig. 1 illustrates the direct paths (D) and some possible structural flanking paths (F). Additional non-structural flanking paths include transmission through common air ducts between rooms, or doors to the corridor from adjacent rooms. Sound isolation is also influenced by the size of the separating partition between spaces and absorption in the receiving space, and in the case of small spaces by modal behavior of the space and close proximity to surfaces.
FIG. 1 Direct (D) and Some Indirect or Flanking Paths (F and Dotted) in a Building  
1.2 The main part of this test method defines procedures and metrics to assess the sound isolation between two rooms or portions thereof in a building separated by a common partition or the apparent sound insulation of the separating partition, including both direct and flanking transmission paths in all cases. Appropriate measures and their single number ratings are the noise reduction (NR) and noise isolation class (NIC) which indicate the isolation with the receiving room furnished as it is during the test, the normalized noise reduction (NNR) and normalized noise isolation class (NNIC) which indicate the isolation expected if the receiving room was a normally furnished living or office space that is at least 25 m3 (especially useful when the test must be done with the receiving room unfurnished), and the apparent transmission loss (ATL) and apparent sound transmission class (ASTC) which indicate the apparent sound insulating properties of a separating partition including both the direct transmission and flanking transmission through the support structure. The measurement of ATL ...

SIGNIFICANCE AND USE
5.1 The noise reduction of an enclosure is a property of the enclosure, the location of the sound source used to measure noise reduction, and the space in which the enclosure is placed. It is not a property of the enclosure alone, and its measurement under different conditions can be expected to give different results. When the noise reduction is measured in accordance with this test method, the sound source is outside the enclosure and the sound field outside the enclosure approximates a diffuse sound field. Measurements made in accordance with this test method can be expected to be reproducible from one laboratory to another.  
5.2 The noise reduction measured in accordance with this test method may be used for the following purposes:  
5.2.1 To rank the order of sound-isolating enclosures according to noise isolation class, NIC.  
5.2.2 To estimate the highest one-third octave band sound pressure levels that can occur outside the enclosure without exceeding specified sound pressure levels inside the enclosure.  
5.2.3 To estimate the one-third octave band sound pressure levels that will occur inside the enclosure with specified sound pressure levels outside.  
5.3 The noise reduction measured in accordance with this test method may not estimate accurately the isolation that the enclosure will provide when it is used to isolate a noise source inside it from the space outside. The user should be cautious when using noise reductions measured by this test method to evaluate enclosures used to enclose noise sources.  
5.4 Sound-isolating enclosures are frequently made from prefabricated modular panels. The noise reduction measured by this test method applies to the complete enclosure and not to individual panels from which it is made and cannot be used to infer the sound transmission loss of the individual panels.  
5.5 Specifications for sound-isolating enclosures may include reference to noise reduction and noise isolation class measured in accordance with th...
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1.1 This test method covers the reverberation room measurement of the noise reduction of sound-isolating enclosures.  
1.2 The noise isolation class may be determined from the noise reduction measured in accordance with this test method.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
4.1 This classification provides a single number rating for transmission loss or noise reduction data that have been measured or calculated. This rating is based on the difference between the overall A-weighted sound level of the sound spectrum given in Table 1 and the overall A-weighted sound level of the spectrum that results from arithmetically subtracting the transmission loss or noise reduction data from this spectrum. The spectrum shape is an average of three spectra from transportation sources (aircraft takeoff, road traffic, and diesel locomotive). A study showed that this classification correlated well with the A-weighted and loudness reductions (based on ISO 532:1975 in effect at the time) calculated for each of the individual spectra used in developing the rating for the one-third-octave band range of 50 Hz to 5000 Hz. The calculated numeric value of the rating is based on the sound transmission loss or noise reduction values for a particular specimen and depends only on that data and the shape of the reference source spectrum used in the calculation. The values shown in Table 1 have an arbitrary reference level. Use single-number ratings with caution. Specimens having the same rating can result in different indoor spectra depending on the variation of their transmission loss with frequency. Also, if the actual spectrum of the outdoor sound is different from that assumed in Table 1, the overall A-weighted outdoor-indoor noise reduction can be different from the OINIC. The strong low-frequency content of the spectrum in Table 1 means that specimen achieving a high rating must have strong low-frequency transmission loss. Use of this classification with the spectrum in Table 1 in situations where the source does not have a spectrum similar to Table 1 could result in requirements for more low-frequency transmission loss than is necessary for the application. Examples where this can occur are stage 3 jet aircraft, high-speed freeways with sound dominated by ti...
SCOPE
1.1 The purpose of this classification is to provide a method to calculate single-number ratings that can be used for assessing the isolation from outdoor sound provided by a building or comparing building facade specimens including walls, doors, windows, and combinations thereof, including complete structures. These ratings are designed to correlate with subjective impressions of the ability of building elements to reduce the penetration of outdoor ground and air transportation noise that contains strong low-frequency sound.2 These ratings provide an evaluation and rank ordering of the performance of test specimens based on their effectiveness at controlling the sound of a specific outdoor sound spectrum called the reference source spectrum.  
1.2 In addition to the calculation method, this classification provides the definition of the outdoor-indoor transmission class which is not defined elsewhere within ASTM standards. Other standards such as Guide E966 define additional ratings based on the method of this classification, one of which is discussed in this classification.  
1.3 The rating does not necessarily relate to the perceived aesthetic quality of the transmitted sound. Different facade elements with similar ratings differ significantly in the proportion of low and high frequency sound that they transmit, and the spectra of sources can vary significantly. It is best to use specific sound transmission loss values, in conjunction with actual spectra of outdoor and indoor sound levels, for making final selections of facade elements.  
1.4 Excluded from the scope of this classification are applications involving noise spectra differing markedly from that shown in Table 1. Thus excluded, for example, would be certain industrial noises with high levels at frequencies below the 80 Hz one-third octave band, relative to levels at higher frequencies, and any source, including some transportation sources, that does not ...

SIGNIFICANCE AND USE
4.1 These single-number ratings correlate in a general way with subjective impressions of sound transmission for speech, radio, television, and similar sources of noise in offices and buildings. This classification method is not appropriate for sound sources with spectra significantly different from those sources listed above. Such sources include machinery, industrial processes, bowling allies, power transformers, musical instruments, many music systems, and transportation noises such as motor vehicles, aircraft and trains. For these sources, accurate assessment of sound transmission requires a detailed analysis in frequency bands. A single-number sound transmission rating for building façade elements is given in Classification E1332.  
4.2 The single-number ratings obtained can be used to compare the potential sound insulation of partitions or floors tested in laboratory conditions (STC) or the actual sound isolation between different suites in buildings (NNIC, NIC). The rating for a partition built and tested in a building may be lower than that obtained for a partition tested in a laboratory because of flanking transmission or construction errors.
Note 1: A similar rating procedure, described in ISO 717-1:2020, provides single figure sound insulation ratings with a frequency range that extends from 100 to 3150 Hz with no maximum deficiency specified at individual frequencies. For most partitions, the two ratings differ by only one or two points.
SCOPE
1.1 This classification covers methods of calculating single-number acoustical ratings for laboratory and field measurements of sound attenuation obtained in one-third octave bands.  
1.2 The name given to the single-number rating is assigned by the test method that invokes this classification.  
1.3 Test methods that invoke this classification include:  
1.3.1 Test Method E90—The single-number rating is called sound transmission class (STC).  
1.3.2 Test Method E336—Single number ratings are noise isolation class (NIC), normalized noise isolation class (NNIC), and apparent sound transmission class (ASTC).  
1.3.3 Test Method E596—The single-number rating is called noise isolation class (NIC).  
1.3.4 Test Method E1414—The single-number rating is called ceiling attenuation class (CAC).  
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

ABSTRACT
This specification describes the construction and installation of standard reference specimens for quality control of laboratory sound transmission loss measurements. The reference specimen is composed of framed steel panels. The required materials for fabrication and installation are as follows: galvanized sheets, frame, and panels. Four kinds of installation may be done: Installation A using a single layer reference specimen, Installation B using double layer reference specimen with a common plate, Installation C using double layer reference specimen with separate plates-empty cavity, and Installation D using double layer reference specimen with separate plates and added layer of sound-absorbing material in the cavity.
SCOPE
1.1 This specification describes the construction and installation of standard reference specimens for quality control of laboratory sound transmission loss measurements using Test Method E90.  
1.2 Laboratories may choose to construct and test all of the reference specimens described here or only a subset. Specific specimens may be required by a test method or an accrediting agency.  
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 This standard provides a method for testing the apparent sound insulating properties of doors in the field originally proposed by Morin (1).6 This allows doors to be evaluated with a result that has been found to be similar to the transmission loss.  
5.2 The results of this measurement are the normalized door insertion loss, NDIL, at individual frequencies, and the single-number rating door transmission class, DTC. The insertion loss is normalized by the small change in sound level which occurs on the source side when the door is opened and closed. The results are in theory the same when measured in each direction through the door, but differences have been observed in practice.  
5.3 Comparative measurements using this method and the method of Test Method E90 on the same door installations in a laboratory indicate good agreement between the transmission loss and normalized door insertion loss when the door is in a wall between two rooms and flanking is not significant. No similar verification has been done for corridors. See Appendix X1 and Ref (2).  
5.4 The fixed-microphone and scanning methods have been compared in the field. See Appendix X2.
SCOPE
1.1 The sound insulation properties of a door are measured in a laboratory as the sound transmission loss in accordance with Test Method E90. Using those data, the single-number rating sound transmission class (STC) is assigned. In the field, the rooms on one or both sides of a partition containing a door are often either too small or too large and absorptive to allow the apparent transmission loss (ATL) of the partition-door assembly to be measured. Even if that is not the case, the result measured is the composite ATL of the partition including the door, and not that of the door itself. Test Method E336 states that it is impossible to measure the ATL of a portion of a partition such as a door according to the procedures of that standard. This test method provides a method of evaluating doors in the field using a normalized insertion loss with a resulting single-number rating door transmission class, DTC. This method is intended primarily for hinged personnel doors with latching mechanisms and is limited to door openings of area less than 6 m2. The flanking effects of surrounding structure are reduced compared to Test Method E336 but not completely eliminated. In a laboratory environment, the DTC is close to or equal to the STC of the door, but in the field results less than the laboratory STC are to be expected due to flanking.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 Modern offices and other multipurpose buildings commonly have suspended acoustical ceilings installed over room dividing partitions. The test facility prescribed in this test method is useful for providing ceiling attenuation data on the relevant ceiling/partition elements and systems, to ensure that the transmission of sound through the ceiling and plenum space, or through the combination of ceiling, plenum space, and partition systems, provides a suitable degree of acoustical isolation.  
5.2 This test method is useful for rating and specifying, under standardized conditions, the sound attenuation performance of ceiling materials when mounted in a specified suspension system.  
5.3 This test method may be useful for selecting a wall-ceiling system for probable compliance with a performance specification for overall sound isolation between rooms. However, the actual field performance may differ significantly, particularly if the field plenum depth is not within the limits specified in this test method or if the plenum space contains large ducts, beams, etc., or both. (See Test Method E336.)  
5.4 The flexibility inherent in the test facility enables evaluation of the effects of penetrations, induced leakage paths, luminaire, and air diffuser installations and discontinuities in the ceiling suspension system at the partition line, including penetration of the partition into the ceiling plenum. The effect of installing plenum barriers at the partition line may also be investigated.  
5.5 With the concentration of sound absorbent area offered by a suspended sound absorbent ceiling installed in a room, it is not possible to obtain a good approximation to a diffuse sound field in that room. The plenum dimensions prevent the maintenance of a diffuse sound field above the test specimen. These factors affect the values of the measured ceiling sound attenuation and thus the measurements are not a fundamental property of the ceiling. The test method measures the acou...
SCOPE
1.1 This test method utilizes a laboratory space so arranged that it simulates a pair of horizontally adjacent small offices or rooms separated by a partition and sharing a common plenum space. The partition either extends to the underside of a common plenum space or penetrates through it. In the prescribed configuration, special design features of the facility ensure that the only significant sound transmission path is by way of the ceiling and the plenum space.  
1.2 Within the limitations outlined in the significance statement, the primary quantity measured by this test method is the ceiling attenuation of a suspended ceiling installed in a laboratory environment. By accounting for receiving room sound absorption, the normalized ceiling attenuation may be determined.  
1.3 The test method may also be used to evaluate the attenuation of composite ceiling systems comprised of the ceiling material and other components such as luminaires and ventilating systems.  
1.4 The field performance of a ceiling system may differ significantly from the results obtained by this test method (see Section 5, Significance and Use, and Test Method E336).  
1.5 The procedures may also be used to study the additional sound insulation that may be achieved by other attenuation measures. This would include materials used either as plenum barriers or as backing for all or part of the ceiling.  
1.6 The facility may also be used to study the performance of an integrated system comprising plenum, ceiling, and partition, tested as a single assembly.  
1.7 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.  
1.8 This standard does not purport to address all of the safety concerns, ...

SIGNIFICANCE AND USE
5.1 This test method can be used to obtain an estimate the transmission loss of building elements in a laboratory setting where the source room and the specimen mounting conditions satisfy the requirements of Test Method E90. The acceptability of the receiving room will be determined by a set of field indicators that define the quality and accuracy of the intensity estimate.  
5.2 By appropriately constructing the surface over which the intensity is measured it is possible to selectively exclude the influence of sound energy paths including the effects from joints, gaps as well as flanking sound paths. This method may be particularly useful when accurate measurements of a partition can not be made in an Test Method E90 facility because the partition sound insulation is limited by flanking transmission involving facility source and receiver room surfaces, (for example, the path from the source room floor to the receiver room floor via the isolators and the slab supporting the two). Annex A3 discusses this in detail.  
5.3 The discrete point method allows the mapping of the radiated sound intensity which can be used to identify defects or unique features (2) of the partition.  
5.4 Current research reported in the literature indicate that there exists a bias between measures of transmission loss obtained using the intensity technique and those obtained using the conventional two room reverberation technique (for example, Test Method E90,  (3) and (4)). Appendix E provides estimates of the bias that might be expected. Despite the presence of a bias, no corrections are to be applied to the measured data obtained by this test method.
SCOPE
1.1 This test method covers the measurement of airborne sound transmission loss of building partitions such as walls of all kinds, operable partitions, floor-ceiling assemblies, doors, windows, roofs, panels and other space-dividing building elements. It may also be have applications in sectors other than the building industry, although these are beyond the scope.  
1.2 The primary quantity reported by this standard is Intensity Transmission Loss (ITL) and shall not be given another name. Similarly, the single-number rating Intensity Sound Transmission Class (ISTC) derived from the measured ITL shall not be given any other name.  
1.3 This test method may be used to reveal the sound radiation characteristics of a partition or portion thereof.  
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
Note 1: The method for measuring the sound intensity radiated by the building element under test defined by this ASTM standard meets or exceeds those of ISO 15186-1. Special consideration will have to be given to requirements for the source room and specimen mounting if compliance with ISO 15186-1 is also desired as they differ from those of this standard.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 The best uses of this guide are to measure the OINR and the AOITL(θ) or OITL(θ) at specific angles of incidence. By measuring the AOITL(θ) or OITL(θ) at several loudspeaker sound incidence angles, by energy-averaging the receiving room sound levels before computing results, an approximation of the diffuse field results measured with Test Methods E90 and E336 may be obtained.  
5.2 The traffic noise method is to be used only for OINR measurements and is most suitable for situations where the OINR of a specimen at a specific location is exposed to an existing traffic noise source.  
5.3 The OINR, AOITL(θ), and OITL(θ) produced by the methods described will not correspond to the transmission loss and noise reduction measured by Test Methods E90 and E336 because of the different incident sound fields that exist in the outdoors (1)4. All of these results are a function of the angle of incidence of the sound for two reasons.  
5.3.1 The transmission loss is strongly influenced by the coincidence effect where the frequency and projected wavelength of sound incident at angle, θ, coincides with the wavelength of a bending wave of the same frequency in the panel  (2, 3, 4, 5). This frequency and the angle of least transmission loss (greatest transparency) both depend on specimen panel stiffness, damping and area mass. In diffuse-field testing as in the laboratory, the effect is a weakness at the diffuse field average coincidence frequency that is dependent on material and thickness, often seen around the frequency of 2500 Hz for drywall and glass specimens. Thick wood panels, such as doors, and masonry wall exhibit lower coincident frequencies while thinner sheet steel exhibits higher coincidence frequencies. For free field sound coming from one direction only, the coincidence frequency varies with incidence angle and will differ from the diffuse-field value  (5). Near or at grazing (θ close to 90°) it will be much lower in frequency than the diffuse field (E90 and E33...
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1.1 This guide may be used to determine the outdoor-indoor noise reduction (OINR), which is the difference in sound pressure level between the free-field level outdoors in the absence of the structure and the resulting sound pressure level in a room. Either a loudspeaker or existing traffic noise or aircraft noise can be used as the source. The outdoor sound field geometry must be described and calculations must account for the way the outdoor level is measured. These results are used with Classification E1332 to calculate the single number rating outdoor-indoor noise isolation class, OINIC. Both OINR and OINIC can vary with outdoor sound incidence angle.  
1.2 Under controlled circumstances where a single façade is exposed to the outdoor sound, or a façade element such as a door or window has much lower transmission loss than the rest of the façade, an outdoor-indoor transmission loss, OITL(θ), or apparent outdoor-indoor transmission loss, AOITL(θ), may be measured using a loudspeaker source. These results are a function of the angle of incidence of the sound field. By measuring with sound incident at many angles, an approximation to the diffuse field transmission loss as measured between two rooms can be obtained. The results may be used to predict interior sound levels in installations similar to that tested when exposed to an outdoor sound field similar to that used during the measurement. The single number ratings of apparent outdoor-indoor transmission class, AOITC(θ), using AOITL(θ) and field outdoor-indoor transmission class, FOITC(θ), using OITL(θ) may be calculated using Classification E1332. These ratings also may be calculated with the data obtained from receiving room sound pressure measurements performed at several incidence angles as discussed in 8.6.  
1.3 To cope with the variety of outdoor incident sound field geometries that are encountered in the field, six testing techniques are presented. These te...

SIGNIFICANCE AND USE
5.1 This guide can be used to produce a specification for the acoustical performance of an enclosure.  
5.2 This guide is intended for those familiar with basic concepts of acoustics.  
5.3 Although this guide provides detailed guidance in matters relating to specification of acoustical enclosures, it is not a substitute for the experience and judgment of an acoustical or noise control professional.  
5.3.1 This guide calls for measurements common within acoustical practice.  
5.3.2 The more critical the performance requirements of the enclosure, the more the user should consider seeking the services of an acoustics or noise control professional.  
5.4 The specifying of a sound-isolating enclosure has three sequential steps:  
5.4.1 Determine the sound pressure levels that exist at specific locations prior to the introduction of the enclosure,
Note 1: In the case of new construction, the sound pressure level is often estimated from the sound power levels of noise-emitting equipment and a general description of the acoustical properties of the environment.  
5.4.2 Determine the maximum permissible sound pressure levels that must exist at the same locations after the introduction of the enclosure, and  
5.4.3 Determine the required enclosure level reduction. The required isolation is related to the difference between the sound pressure levels before and after the introduction of the enclosure.  
5.5 Many specifications are for multiple enclosures or enclosures with multiple functions, or both. It is beyond the scope of this guide to provide detailed guidance for every possible combination. Separate specifications for each source-enclosure-receiver combination should be used in such a case.  
5.6 The type of specification that should be selected depends both on the purpose of the enclosure and how crucial its performance is. In general:  
5.6.1 If exceeding a particular maximum permissible sound pressure level spectrum would render the enclosure unsuccessf...
SCOPE
1.1 The guide covers the development of criteria for the acoustical performance of a broad variety of acoustical enclosures by identifying information necessary to unambiguously describe acoustical performance. This guide is not a standard ASTM specification for a sound-isolating enclosure.  
1.2 Excluded from the scope of this guide are technical considerations for enclosure design that do not pertain directly to acoustical performance.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 Modern offices and other multipurpose buildings commonly have suspended acoustical ceilings installed over room dividing partitions. The test facility prescribed in this test method is useful for providing ceiling attenuation data on the relevant ceiling/partition elements and systems, to ensure that the transmission of sound through the ceiling and plenum space, or through the combination of ceiling, plenum space, and partition systems, provides a suitable degree of acoustical isolation.  
5.2 This test method is useful for rating and specifying, under standardized conditions, the sound attenuation performance of ceiling materials when mounted in a specified suspension system.  
5.3 This test method may be useful for selecting a wall-ceiling system for probable compliance with a performance specification for overall sound isolation between rooms. However, the actual field performance may differ significantly, particularly if the field plenum depth is not within the limits specified in this test method or if the plenum space contains large ducts, beams, etc., or both. (See Test Method E336.)  
5.4 The flexibility inherent in the test facility enables evaluation of the effects of penetrations, induced leakage paths, luminaire, and air diffuser installations and discontinuities in the ceiling suspension system at the partition line, including penetration of the partition into the ceiling plenum. The effect of installing plenum barriers at the partition line may also be investigated.  
5.5 With the concentration of sound absorbent area offered by a suspended sound absorbent ceiling installed in a room, it is not possible to obtain a good approximation to a diffuse sound field in that room. The plenum dimensions prevent the maintenance of a diffuse sound field above the test specimen. These factors affect the values of the measured ceiling sound attenuation and thus the measurements are not a fundamental property of the ceiling. The test method measures the acou...
SCOPE
1.1 This test method utilizes a laboratory space so arranged that it simulates a pair of horizontally adjacent small offices or rooms separated by a partition and sharing a common plenum space. The partition either extends to the underside of a common plenum space or penetrates through it. In the prescribed configuration, special design features of the facility ensure that the only significant sound transmission path is by way of the ceiling and the plenum space.  
1.2 Within the limitations outlined in the significance statement, the primary quantity measured by this test method is the ceiling attenuation of a suspended ceiling installed in a laboratory environment. By accounting for receiving room sound absorption, the normalized ceiling attenuation may be determined.  
1.3 The test method may also be used to evaluate the attenuation of composite ceiling systems comprised of the ceiling material and other components such as luminaires and ventilating systems.  
1.4 The field performance of a ceiling system may differ significantly from the results obtained by this test method (see Section 5, Significance and Use, and Test Method E336).  
1.5 The procedures may also be used to study the additional sound insulation that may be achieved by other attenuation measures. This would include materials used either as plenum barriers or as backing for all or part of the ceiling.  
1.6 The facility may also be used to study the performance of an integrated system comprising plenum, ceiling, and partition, tested as a single assembly.  
1.7 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.  
1.8 This standard does not purport to address all of the safety concerns, ...

SIGNIFICANCE AND USE
5.1 The main part of this standard uses procedures originally developed for laboratory measurements of the sound transmission loss of partitions. These procedures assume that the rooms in which the measurements are performed have a sound field that reasonably approximates a diffuse field. Sound pressure levels in such rooms are reasonably uniform throughout the room and average levels vary inversely with the logarithm of the room sound absorption. Not all rooms will satisfy these conditions. Experience and controlled studies (1)6 have shown that the test method is applicable to smaller spaces normally used for work or living, such as rooms in multi-family dwellings, hotel guest rooms, meeting rooms, and offices with volumes less than 150 cubic meters. The measures appropriate for such spaces are NR, NNR, and ATL. The corresponding single number ratings are NIC, NNIC and ASTC. The ATL and ASTC are measurable between larger spaces that meet a limitation on absorption in the spaces to provide uniform sound distribution.  
5.2 Annex A1 was developed for use in spaces that are very large (volume of 150 m3 or greater). Sound pressure levels during testing vary markedly across large rooms so that the degree of isolation varies strongly with distance from the common (separating) partition. This procedure evaluates the isolation observed near the partition. The appropriate measure is NR, and the appropriate single number rating is NIC.  
5.3 Several metrics are available for specific uses. Some evaluate the overall sound isolation between spaces including the effect of absorption in the receiving space and some evaluate the performance or apparent performance of the partition being evaluated. The results obtained are applicable only to the specific location tested.  
5.3.1 Noise Reduction (NR) and Noise Isolation Class (NIC)—Describe the sound isolation found between two spaces. Noise reduction data are based on the space- and time averaged sound pressure levels meeting t...
SCOPE
1.1 The sound isolation between two spaces in a building is influenced most strongly by a combination of the direct transmission through the nominally separating building element (as normally measured in a laboratory) and any transmission along a number of indirect paths, referred to as flanking paths. Fig. 1 illustrates the direct paths (D) and some possible structural flanking paths (F). Additional non-structural flanking paths include transmission through common air ducts between rooms, or doors to the corridor from adjacent rooms. Sound isolation is also influenced by the size of the separating partition between spaces and absorption in the receiving space, and in the case of small spaces by modal behavior of the space and close proximity to surfaces.
FIG. 1 Direct (D) and Some Indirect or Flanking Paths (F and Dotted) in a Building  
1.2 The main part of this test method defines procedures and metrics to assess the sound isolation between two rooms or portions thereof in a building separated by a common partition or the apparent sound insulation of the separating partition, including both direct and flanking transmission paths in all cases. Appropriate measures and their single number ratings are the noise reduction (NR) and noise isolation class (NIC) which indicate the isolation with the receiving room furnished as it is during the test, the normalized noise reduction (NNR) and normalized noise isolation class (NNIC) which indicate the isolation expected if the receiving room was a normally furnished living or office space that is at least 25 m3 (especially useful when the test must be done with the receiving room unfurnished), and the apparent transmission loss (ATL) and apparent sound transmission class (ASTC) which indicate the apparent sound insulating properties of a separating partition including both the direct transmission and flanking transmission through the support structure. The measurement of ATL ...

SIGNIFICANCE AND USE
5.1 The main part of this standard uses procedures originally developed for laboratory measurements of the sound transmission loss of partitions. These procedures assume that the rooms in which the measurements are performed have a sound field that reasonably approximates a diffuse field. Sound pressure levels in such rooms are reasonably uniform throughout the room and average levels vary inversely with the logarithm of the room sound absorption. Not all rooms will satisfy these conditions. Experience and controlled studies (1)6 have shown that the test method is applicable to smaller spaces normally used for work or living, such as rooms in multi-family dwellings, hotel guest rooms, meeting rooms, and offices with volumes less than 150 cubic meters. The measures appropriate for such spaces are NR, NNR, and ATL. The corresponding single number ratings are NIC, NNIC and ASTC. The ATL and ASTC are measurable between larger spaces that meet a limitation on absorption in the spaces to provide uniform sound distribution.  
5.2 Annex A1 was developed for use in spaces that are very large (volume of 150 m3 or greater). Sound pressure levels during testing vary markedly across large rooms so that the degree of isolation varies strongly with distance from the common (separating) partition. This procedure evaluates the isolation observed near the partition. The appropriate measure is NR, and the appropriate single number rating is NIC.  
5.3 Several metrics are available for specific uses. Some evaluate the overall sound isolation between spaces including the effect of absorption in the receiving space and some evaluate the performance or apparent performance of the partition being evaluated. The results obtained are applicable only to the specific location tested.  
5.3.1 Noise Reduction (NR) and Noise Isolation Class (NIC)—Describe the sound isolation found between two spaces. Noise reduction data are based on the space- and time averaged sound pressure levels meeting t...
SCOPE
1.1 The sound isolation between two spaces in a building is influenced most strongly by a combination of the direct transmission through the nominally separating building element (as normally measured in a laboratory) and any transmission along a number of indirect paths, referred to as flanking paths. Fig. 1 illustrates the direct paths (D) and some possible structural flanking paths (F). Additional non-structural flanking paths include transmission through common air ducts between rooms, or doors to the corridor from adjacent rooms. Sound isolation is also influenced by the size of the separating partition between spaces and absorption in the receiving space, and in the case of small spaces by modal behavior of the space and close proximity to surfaces.
FIG. 1 Direct (D) and Some Indirect or Flanking Paths (F and Dotted) in a Building  
1.2 The main part of this test method defines procedures and metrics to assess the sound isolation between two rooms or portions thereof in a building separated by a common partition or the apparent sound insulation of the separating partition, including both direct and flanking transmission paths in all cases. Appropriate measures and their single number ratings are the noise reduction (NR) and noise isolation class (NIC) which indicate the isolation with the receiving room furnished as it is during the test, the normalized noise reduction (NNR) and normalized noise isolation class (NNIC) which indicate the isolation expected if the receiving room was a normally furnished living or office space that is at least 25 m3 (especially useful when the test must be done with the receiving room unfurnished), and the apparent transmission loss (ATL) and apparent sound transmission class (ASTC) which indicate the apparent sound insulating properties of a separating partition including both the direct transmission and flanking transmission through the support structure. The measurement of ATL ...

SIGNIFICANCE AND USE
5.1 This standard provides a method for testing the apparent sound insulating properties of doors in the field originally proposed by Morin (1).6 This allows doors to be evaluated with a result that has been found to be similar to the transmission loss.  
5.2 The results of this measurement are the normalized door insertion loss, NDIL, at individual frequencies, and the single number rating door transmission class, DTC. The insertion loss is normalized by the small change in sound level which occurs on the source side when the door is opened and closed.  
5.3 Comparative measurements using this method and the method of Test Method E90 on the same door installations in a laboratory indicate good agreement between the transmission loss and normalized door insertion loss. See Appendix X1 and Ref (2).  
5.4 The fixed-microphone and scanning methods have been compared in the field. See Appendix X2.
SCOPE
1.1 The sound insulation properties of a door are measured in a laboratory as the sound transmission loss in accordance with Test Method E90. Using those data single number rating sound transmission class (STC) is assigned. In the field, the rooms on one or both sides of a partition containing a door are often either too small or too large and absorptive to allow the apparent transmission loss (ATL) of the partition-door assembly to be measured. Even if that is not the case, the result measured is the composite ATL of the partition including the door, and not that of the door itself. Test Method E336 actually states that it is impossible to measure the ATL of a portion of a partition such as a door according to the procedures of that standard. This test method provides a method of evaluating doors in such cases using a normalized insertion loss with a resulting single number rating door transmission class, DTC. This method is intended primarily for hinged personnel doors with latching mechanisms and is limited to door openings of area less than 6 m2. The flanking effects of surrounding structure are reduced compared to Test Method E336 but not completely eliminated. In a laboratory environment, the DTC is close to or equal to the STC of the door, but in the field results less than the laboratory STC should be expected.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
5.1 The main part of this standard uses procedures originally developed for laboratory measurements of the sound transmission loss of partitions. These procedures assume that the rooms in which the measurements are performed have a sound field that reasonably approximates a diffuse field. Sound pressure levels in such rooms are reasonably uniform throughout the room and average levels vary inversely with the logarithm of the room sound absorption. Not all rooms will satisfy these conditions. Experience and controlled studies (1)6 have shown that the test method is applicable to smaller spaces normally used for work or living, such as rooms in multi-family dwellings, hotel guest rooms, meeting rooms, and offices with volumes less than 150 cubic meters. The measures appropriate for such spaces are NR, NNR, and ATL. The corresponding single number ratings are NIC, NNIC and ASTC. The ATL and ASTC are measurable between larger spaces that meet a limitation on absorption in the spaces to provide uniform sound distribution.  
5.2 Annex A1 was developed for use in spaces that are very large (volume of 150 m3 or greater). Sound pressure levels during testing vary markedly across large rooms so that the degree of isolation varies strongly with distance from the common (separating) partition. This procedure evaluates the isolation observed near the partition. The appropriate measure is NR, and the appropriate single number rating is NIC.  
5.3 Several metrics are available for specific uses. Some evaluate the overall sound isolation between spaces including the effect of absorption in the receiving space and some evaluate the performance or apparent performance of the partition being evaluated. The results obtained are applicable only to the specific location tested.  
5.3.1 Noise Reduction (NR) and Noise Isolation Class (NIC)—Describe the sound isolation found between two spaces. Noise reduction data are based on the space- and time averaged sound pressure levels meeting t...
SCOPE
1.1 The sound isolation between two spaces in a building is influenced most strongly by a combination of the direct transmission through the nominally separating building element (as normally measured in a laboratory) and any transmission along a number of indirect paths, referred to as flanking paths. Fig. 1 illustrates the direct paths (D) and some possible structural flanking paths (F). Additional non-structural flanking paths include transmission through common air ducts between rooms, or doors to the corridor from adjacent rooms. Sound isolation is also influenced by the size of the separating partition between spaces and absorption in the receiving space, and in the case of small spaces by modal behavior of the space and close proximity to surfaces.
FIG. 1 Direct (D) and Some Indirect or Flanking Paths (F and Dotted) in a Building  
1.2 The main part of this test method defines procedures and metrics to assess the sound isolation between two rooms or portions thereof in a building separated by a common partition or the apparent sound insulation of the separating partition, including both direct and flanking transmission paths in all cases. Appropriate measures and their single number ratings are the noise reduction (NR) and noise isolation class (NIC) which indicate the isolation with the receiving room furnished as it is during the test, the normalized noise reduction (NNR) and normalized noise isolation class (NNIC) which indicate the isolation expected if the receiving room was a normally furnished living or office space that is at least 25 m3 (especially useful when the test must be done with the receiving room unfurnished), and the apparent transmission loss (ATL) and apparent sound transmission class (ASTC) which indicate the apparent sound insulating properties of a separating partition including both the direct transmission and flanking transmission through the support structure. The measurement of ATL ...

SIGNIFICANCE AND USE
5.1 The best uses of this guide are to measure the OINR and the AOITL(θ) or OITL(θ) at specific angles of incidence. By measuring the AOITL(θ) or OITL(θ) at several loudspeaker sound incidence angles, by energy-averaging the receiving room sound levels before computing results, an approximation of the diffuse field results measured with Test Methods E90 and E336 may be obtained.  
5.2 The traffic noise method is to be used only for OINR measurements and is most suitable for situations where the OINR of a specimen at a specific location is exposed to an existing traffic noise source.  
5.3 The OINR, AOITL(θ), and OITL(θ) produced by the methods described will not correspond to the transmission loss and noise reduction measured by Test Methods E90 and E336 because of the different incident sound fields that exist in the outdoors (1)4. All of these results are a function of the angle of incidence of the sound for two reasons.  
5.3.1 The transmission loss is strongly influenced by the coincidence effect where the frequency and projected wavelength of sound incident at angle, θ, coincides with the wavelength of a bending wave of the same frequency in the panel  (2, 3, 4, 5). This frequency and the angle of least transmission loss (greatest transparency) both depend on specimen panel stiffness, damping and area mass. In diffuse-field testing as in the laboratory, the effect is a weakness at the diffuse field average coincidence frequency that is dependent on material and thickness, often seen around the frequency of 2500 Hz for drywall and glass specimens. Thick wood panels, such as doors, and masonry wall exhibit lower coincident frequencies while thinner sheet steel exhibits higher coincidence frequencies. For free field sound coming from one direction only, the coincidence frequency varies with incidence angle and will differ from the diffuse-field value  (5). Near or at grazing (θ close to 90°) it will be much lower in frequency than the diffuse field (E90 and E33...
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1.1 This guide may be used to determine the outdoor-indoor noise reduction (OINR), which is the difference in sound pressure level between the free-field level outdoors in the absence of the structure and the resulting sound pressure level in a room. Either a loudspeaker or existing traffic noise or aircraft noise can be used as the source. The outdoor sound field geometry must be described and calculations must account for the way the outdoor level is measured. These results are used with Classification E1332 to calculate the single number rating outdoor-indoor noise isolation class, OINIC. Both OINR and OINIC can vary with outdoor sound incidence angle.  
1.2 Under controlled circumstances where a single façade is exposed to the outdoor sound, or a façade element such as a door or window has much lower transmission loss than the rest of the façade, an outdoor-indoor transmission loss, OITL(θ), or apparent outdoor-indoor transmission loss, AOITL(θ), may be measured using a loudspeaker source. These results are a function of the angle of incidence of the sound field. By measuring with sound incident at many angles, an approximation to the diffuse field transmission loss as measured between two rooms can be obtained. The results may be used to predict interior sound levels in installations similar to that tested when exposed to an outdoor sound field similar to that used during the measurement. The single number ratings of apparent outdoor-indoor transmission class, AOITC(θ), using AOITL(θ) and field outdoor-indoor transmission class, FOITC(θ), using OITL(θ) may be calculated using Classification E1332. These ratings also may be calculated with the data obtained from receiving room sound pressure measurements performed at several incidence angles as discussed in 8.6.  
1.3 To cope with the variety of outdoor incident sound field geometries that are encountered in the field, six testing techniques are presented. These te...

SIGNIFICANCE AND USE
5.1 The main part of this standard uses procedures originally developed for laboratory measurements of the sound transmission loss of partitions. These procedures assume that the rooms in which the measurements are made have a sound field that reasonably approximates a diffuse field. Sound pressure levels in such rooms are reasonably uniform throughout the room and average levels vary inversely with the logarithm of the room sound absorption. Not all rooms will satisfy these conditions. Practical experience and controlled studies (1)6 have shown that the test method is applicable to smaller spaces normally used for work or living, such as rooms in multi-family dwellings, hotel guest rooms, meeting rooms, and offices with volumes less than 150 cubic meters. The measures appropriate for such spaces are NR, NNR, and ATL. The corresponding single number ratings are NIC, NNIC and ASTC. The ATL and ASTC may be measured between larger spaces that meet a limitation on absorption in the spaces to provide uniform sound distribution.  
5.2 Annex A1 was developed for use in spaces that are very large (volume of 150 m3 or greater). Sound pressure levels during testing can vary markedly across large rooms so that the degree of isolation can vary strongly with distance from the common (separating) partition. This procedure evaluates the isolation observed near the partition. The appropriate measure is NR, and the appropriate single number rating is NIC.  
5.3 Several metrics are available for specific uses. Some evaluate the overall sound isolation between spaces including the effect of absorption in the receiving space and some evaluate the performance or apparent performance of the partition being evaluated. The results obtained are applicable only to the specific location tested.  
5.3.1 Noise Reduction (NR) and Noise Isolation Class (NIC)—Describe the sound isolation found between the two spaces under consideration. Noise reduction data are based on the space- and time aver...
SCOPE
1.1 The sound isolation between two spaces in a building is influenced most strongly by a combination of the direct transmission through the nominally separating building element (as normally measured in a laboratory) and any transmission along a number of indirect paths, usually referred to as flanking paths. Fig. 1 illustrates the direct paths (D) and some possible structural flanking paths (F). Additional non-structural flanking paths may include transmission through common air ducts between rooms, or doors to the corridor from adjacent rooms. Sound isolation is also influenced by the size of the separating partition between spaces and absorption in the receiving space, and in the case of small spaces by modal behavior of the space and close proximity to surfaces.
FIG. 1 Direct (D) and Some Indirect or Flanking Paths (F and Dotted) in a Building  
1.2 The main part of this test method defines procedures and metrics to assess the sound isolation between two rooms or portions thereof in a building separated by a common partition or the apparent sound insulation of the separating partition, including both direct and flanking transmission paths in all cases. Appropriate measures and their single number ratings are the noise reduction (NR) and noise isolation class (NIC) which indicate the isolation with the receiving room furnished as it is during the test, the normalized noise reduction (NNR) and normalized noise isolation class (NNIC) which indicate the expected isolation when the receiving room is a normally furnished living or office space that is at least 25 m3 (especially useful when the test must be done with the receiving room unfurnished), and the apparent transmission loss (ATL) and apparent sound transmission class (ASTC) which indicate the apparent sound insulating properties of a separating partition including both the direct transmission and flanking transmission through the support structure. The measur...

SIGNIFICANCE AND USE
5.1 The main part of this standard uses procedures originally developed for laboratory measurements of the transmission loss of partitions. These procedures assume that the rooms in which the measurements are made have a sound field that reasonably approximates a diffuse field. Sound pressure levels in such rooms are reasonably uniform throughout the room and average levels vary inversely with the logarithm of the room sound absorption. Not all rooms will satisfy these conditions. Practical experience and controlled studies (1)6 have shown that the test method is applicable to smaller spaces normally used for work or living, such as rooms in multi-family dwellings, hotel guest rooms, meeting rooms, and offices with volumes less than 150 cubic meters. The measures appropriate for such spaces are NR, NNR, and ATL. The corresponding single number ratings are NIC, NNIC and ASTC. The ATL and ASTC may be measured between larger spaces that meet a limitation on absorption in the spaces to provide uniform sound distribution.  
5.2 Annex A2 was developed for use in spaces that are very large (volume of 150 m3 or greater). Sound pressure levels during testing can vary markedly across large rooms so that the degree of isolation can vary strongly with distance from the common (separating) partition. This procedure evaluates the isolation observed near the partition. The appropriate measure is NR, and the appropriate single number rating is NIC.  
5.3 It is sometimes necessary to demonstrate that the sound insulation of a partition meets or exceeds a specific criterion. Annex A1 provides additional requirements, and describes how shielding procedures can be used to reduce flanking transmission in stages to show that a partition has achieved a minimum value of the FTL or minimum value of the FSTC which may meet or exceed the criterion. If it is demonstrated that no significant flanking exists through shielding of all potential flanking paths, then, and only then, FTL and FSTC m...
SCOPE
1.1 The sound isolation between two spaces in a building is influenced most strongly by a combination of the direct transmission through the nominally separating building element (as normally measured in a laboratory) and any transmission along a number of indirect paths, usually referred to as flanking paths. Fig. 1 illustrates the direct paths and some possible structural flanking paths. Additional non-structural flanking paths may include transmission through common air ducts between rooms, or doors to the corridor from adjacent rooms. Sound isolation is also influenced by the size of the separating partition between spaces and absorption in the receiving space, and in the case of small spaces by modal behavior of the space and close proximity to surfaces.
FIG. 1 Direct (D) and Some Indirect or Flanking Paths (F and Dotted) in a Building  
1.2 The main part of this test method defines procedures and metrics to assess the sound isolation between two rooms or portions thereof in a building separated by a common partition or the apparent sound insulation of the separating partition, including both direct and flanking transmission paths in all cases. Appropriate measures and their single number ratings are the noise reduction (NR) and noise isolation class (NIC) which indicate the isolation with the receiving room furnished as it is during the test, the normalized noise reduction (NNR) and normalized noise isolation class (NNIC) which indicate the expected isolation when the receiving room is a normally furnished living or office space that is at least 25 m3 (especially useful when the test must be done with the receiving room unfurnished), and the apparent transmission loss (ATL) and apparent sound transmission class (ASTC) which indicate the apparent sound insulating properties of a separating partition. The measurement of ATL is limited to spaces of at least 25 m3 where modal effects create fewer problems. With the...

SIGNIFICANCE AND USE
5.1 Sound transmission loss as defined in Terminology C634, refers to the response of specimens exposed to a diffuse incident sound field, and this is the test condition approached by this laboratory test method. The test results are therefore most directly relevant to the performance of similar specimens exposed to similar sound fields. They provide, however, a useful general measure of performance for the variety of sound fields to which a partition or element may typically be exposed.  
5.2 In laboratories designed to satisfy the requirements of this test method, the intent is that only significant path for sound transmission between the rooms is through the test specimen. This is not generally the case in buildings where there are often many other paths for sounds—flanking sound transmission. Consequently sound ratings obtained using this test method do not relate directly to sound isolation in buildings; they represent an upper limit to what would be measured in a field test.  
5.3 This test method is not intended for field tests. Field tests shall be performed according to Test Method E336.
Note 2: The comparable quantity measured using Test Method E336 is called the apparent sound transmission loss because of the presence of flanking sound transmission.
SCOPE
1.1 This test method covers the laboratory measurement of airborne sound transmission loss of building partitions such as walls of all kinds, operable partitions, floor-ceiling assemblies, doors, windows, roofs, panels, and other space-dividing elements.  
1.2 Laboratories are designed so the test specimen constitutes the primary sound transmission path between the two test rooms and so approximately diffuse sound fields exist in the rooms.  
1.3 Laboratory Accreditation—The requirements for accrediting a laboratory for performing this test method are given in Annex A4.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
4.1 This classification provides a single number rating for transmission loss or noise reduction data that have been measured or calculated. This rating is based on the difference between the overall A-weighted sound level of the sound spectrum given in Table 1 and the overall A-weighted sound level of the spectrum that results from arithmetically subtracting the transmission loss or noise reduction data from this spectrum. The spectrum shape is an average of three spectra from transportation sources (aircraft takeoff, road, and diesel locomotive passby). A study showed that this classification correlated well with the A-weighted and loudness reductions (see ISO 532) calculated for each of the individual spectra used in developing the rating for the one-third octave band range of 50 to 5000 Hz. The calculated numeric value of the rating is based on the sound transmission loss or noise reduction values for a particular specimen and depends only on that data and the shape of the reference source spectrum used in the calculation. The values shown in Table 1 have an arbitrary reference level. Single-number ratings should always be used with caution. Specimens having the same rating can result in different indoor spectra depending on the variation of their transmission loss with frequency. Also, if the actual spectrum of the outdoor sound is different from that assumed in Table 1, the overall A-weighted outdoor-indoor noise reduction may be different from the OINIC. The strong low-frequency content of the spectrum in Table 1 means that specimen achieving a high rating must have strong low-frequency transmission loss. Use of this classification with the spectrum in Table 1 in situations where the source does not have a spectrum similar to Table 1 could result in requirements for more low-frequency transmission loss than is necessary for the application. Examples where this can occur are stage 3 jet aircraft, high-speed freeways with sound dominated by tire noise, and trai...
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1.1 The purpose of this classification is to provide a method to calculate single-number ratings that can be used for assesing the isolation for the outdoor sound provided by a building or comparing building facade specimens including walls, doors, windows, and combinations thereof, including complete structures. These ratings are designed to correlate with subjective impressions of the ability of building elements to reduce the penetration of outdoor ground and air transportation noise that contains strong low-frequency sound.2 These ratings provide an evaluation and rank ordering of the performance of test specimens based on their effectiveness at controlling the sound of a specific outdoor sound spectrum called the reference source spectrum.  
1.2 In addition to the calculation method, this classification defines some ratings not defined in other standards. Other standards may define additional ratings based on the method of this classification.  
1.3 The rating does not necessarily relate to the perceived aesthetic quality of the transmitted sound. Different facade elements with similar ratings may differ significantly in the proportion of low and high frequency sound that they transmit and the spectra of sources can vary significantly. It is best to use specific sound transmission loss values, in conjunction with actual spectra of outdoor and indoor sound levels, for making final selections of facade elements.  
1.4 Excluded from the scope of this classification are applications involving noise spectra differing markedly from that shown in Table 1. Thus excluded, for example, would be certain industrial noises with high levels at frequencies below the 80 Hz one-third octave band, relative to levels at higher frequencies, and any source, including some transportation sources, that does not have a spectrum similar to that in Table 1. However, for any source with a spectrum similar to that in Table 1, this classific...

SIGNIFICANCE AND USE
5.1 The main part of this standard uses procedures originally developed for laboratory measurements of the transmission loss of partitions. These procedures assume that the rooms in which the measurements are made have a sound field that reasonably approximates a diffuse field. Sound pressure levels in such rooms are reasonably uniform throughout the room and average levels vary inversely with the logarithm of the room sound absorption. Not all rooms will satisfy these conditions. Practical experience and controlled studies (1)6 have shown that the test method is applicable to smaller spaces normally used for work or living, such as rooms in multi-family dwellings, hotel guest rooms, meeting rooms, and offices with volumes less than 150 cubic meters. The measures appropriate for such spaces are NR, NNR, and ATL. The corresponding single number ratings are NIC, NNIC and ASTC. The ATL and ASTC may be measured between larger spaces that meet a limitation on absorption in the spaces to provide uniform sound distribution.  
5.2 Annex A2 was developed for use in spaces that are very large (volume of 150 m3 or greater). Sound pressure levels during testing can vary markedly across large rooms so that the degree of isolation can vary strongly with distance from the common (separating) partition. This procedure evaluates the isolation observed near the partition. The appropriate measure is NR, and the appropriate single number rating is NIC.  
5.3 It is sometimes necessary to demonstrate that the sound insulation of a partition meets or exceeds a specific criterion. Annex A1 provides additional requirements, and describes how shielding procedures can be used to reduce flanking transmission in stages to show that a partition has achieved a minimum value of the FTL or minimum value of the FSTC which may meet or exceed the criterion. If it is demonstrated that no significant flanking exists through shielding of all potential flanking paths, then, and only then, FTL and FSTC m...
SCOPE
1.1 The sound isolation between two spaces in a building is influenced most strongly by a combination of the direct transmission through the nominally separating building element (as normally measured in a laboratory) and any transmission along a number of indirect paths, usually referred to as flanking paths. Fig. 1 illustrates the direct paths and some possible structural flanking paths. Additional non-structural flanking paths may include transmission through common air ducts between rooms, or doors to the corridor from adjacent rooms. Sound isolation is also influenced by the size of the separating partition between spaces and absorption in the receiving space, and in the case of small spaces by modal behavior of the space and close proximity to surfaces.  
1.2 The main part of this test method defines procedures and metrics to assess the sound isolation between two rooms or portions thereof in a building separated by a common partition or the apparent sound insulation of the separating partition, including both direct and flanking transmission paths in all cases. Appropriate measures and their single number ratings are the noise reduction (NR) and noise isolation class (NIC) which indicate the isolation with the receiving room furnished as it is during the test, the normalized noise reduction (NNR) and normalized noise isolation class (NNIC) which indicate the expected isolation when the receiving room is a normally furnished living or office space that is at least 25 m3 (especially useful when the test must be done with the receiving room unfurnished), and the apparent transmission loss (ATL) and apparent sound transmission class (ASTC) which indicate the apparent sound insulating properties of a separating partition. The measurement of ATL is limited to spaces of at least 25 m3 where modal effects create fewer problems. With the exception of the ATL and ASTC under specified conditions, these procedures in the ma...

SIGNIFICANCE AND USE
5.1 Modern offices and other multipurpose buildings commonly have suspended acoustical ceilings installed over room dividing partitions. The test facility prescribed in this test method is useful for providing ceiling attenuation data on the relevant ceiling/partition elements and systems, to ensure that the transmission of sound through the ceiling and plenum space, or through the combination of ceiling, plenum space, and partition systems, provides a suitable degree of acoustical isolation.  
5.2 This test method is useful for rating and specifying, under standardized conditions, the sound attenuation performance of ceiling materials when mounted in a specified suspension system.  
5.3 This test method may be useful for selecting a wall-ceiling system for probable compliance with a performance specification for overall sound isolation between rooms. However, the actual field performance may differ significantly, particularly if the field plenum depth is not within the limits specified in this test method or if the plenum space contains large ducts, beams, etc., or both. (See Test Method E336.)  
5.4 The flexibility inherent in the test facility enables evaluation of the effects of penetrations, induced leakage paths, luminaire, and air diffuser installations and discontinuities in the ceiling suspension system at the partition line, including penetration of the partition into the ceiling plenum. The effect of installing plenum barriers at the partition line may also be investigated.  
5.5 With the concentration of sound absorbent area offered by a suspended sound absorbent ceiling installed in a room, it is not possible to obtain a good approximation to a diffuse sound field in that room. The plenum dimensions prevent the maintenance of a diffuse sound field above the test specimen. These factors affect the values of the measured ceiling sound attenuation and thus the measurements are not a fundamental property of the ceiling. The test method measures the acou...
SCOPE
1.1 This test method utilizes a laboratory space so arranged that it simulates a pair of horizontally adjacent small offices or rooms separated by a partition and sharing a common plenum space. The partition either extends to the underside of a common plenum space or penetrates through it. In the prescribed configuration, special design features of the facility ensure that the only significant sound transmission path is by way of the ceiling and the plenum space.  
1.2 Within the limitations outlined in the significance statement, the primary quantity measured by this test method is the ceiling attenuation of a suspended ceiling installed in a laboratory environment. By accounting for receiving room sound absorption, the normalized ceiling attenuation may be determined.  
1.3 The test method may also be used to evaluate the attenuation of composite ceiling systems comprised of the ceiling material and other components such as luminaires and ventilating systems.  
1.4 The field performance of a ceiling system may differ significantly from the results obtained by this test method (see Section 5, Significance and Use, and Test Method E336).  
1.5 The procedures may also be used to study the additional sound insulation that may be achieved by other attenuation measures. This would include materials used either as plenum barriers or as backing for all or part of the ceiling.  
1.6 The facility may also be used to study the performance of an integrated system comprising plenum, ceiling, and partition, tested as a single assembly.  
1.7 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.  
1.8 This standard does not purport to address all of the safety concerns, ...

ABSTRACT
This specification describes the construction and installation of standard reference specimens for quality control of laboratory sound transmission loss measurements. The reference specimen is composed of framed steel panels. The required materials for fabrication and installation are as follows: galvanized sheets, frame, and panels. Four kinds of installation may be done: Installation A using a single layer reference specimen, Installation B using double layer reference specimen with a common plate, Installation C using double layer reference specimen with separate plates-empty cavity, and Installation D using double layer reference specimen with separate plates and added layer of sound-absorbing material in the cavity.
SCOPE
1.1 This specification describes the construction and installation of standard reference specimens for quality control of laboratory sound transmission loss measurements using Test Method E90.  
1.2 Laboratories may choose to construct and test all of the reference specimens described here or only a subset. Specific specimens may be required by a test method or an accrediting agency.  
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.

SIGNIFICANCE AND USE
5.1 This test method can be used to obtain an estimate the transmission loss of building elements in a laboratory setting where the source room and the specimen mounting conditions satisfy the requirements of Test Method E90. The acceptability of the receiving room will be determined by a set of field indicators that define the quality and accuracy of the intensity estimate.  
5.2 By appropriately constructing the surface over which the intensity is measured it is possible to selectively exclude the influence of sound energy paths including the effects from joints, gaps as well as flanking sound paths. This method may be particularly useful when accurate measurements of a partition can not be made in an Test Method E90 facility because the partition sound insulation is limited by flanking transmission involving facility source and receiver room surfaces, (for example, the path from the source room floor to the receiver room floor via the isolators and the slab supporting the two). Annex A3 discusses this in detail.  
5.3 The discrete point method allows the mapping of the radiated sound intensity which can be used to identify defects or unique features (2) of the partition.  
5.4 Current research reported in the literature indicate that there exists a bias between measures of transmission loss obtained using the intensity technique and those obtained using the conventional two room reverberation technique (for example, Test Method E90,  (3) and (4)). Appendix E provides estimates of the bias that might be expected. Despite the presence of a bias, no corrections are to be applied to the measured data obtained by this test method.
SCOPE
1.1 This test method covers the measurement of airborne sound transmission loss of building partitions such as walls of all kinds, operable partitions, floor-ceiling assemblies, doors, windows, roofs, panels and other space-dividing building elements. It may also be have applications in sectors other than the building industry, although these are beyond the scope.  
1.2 The primary quantity reported by this standard is Intensity Transmission Loss (ITL) and shall not be given another name. Similarly, the single-number rating Intensity Sound Transmission Class (ISTC) derived from the measured ITL shall not be given any other name.  
1.3 This test method may be used to reveal the sound radiation characteristics of a partition or portion thereof.  
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
Note 1: The method for measuring the sound intensity radiated by the building element under test defined by this ASTM standard meets or exceeds those of ISO 15186-1. Special consideration will have to be given to requirements for the source room and specimen mounting if compliance with ISO 15186-1 is also desired as they differ from those of this standard.

SIGNIFICANCE AND USE
4.1 These single-number ratings correlate in a general way with subjective impressions of sound transmission for speech, radio, television, and similar sources of noise in offices and buildings. This classification method is not appropriate for sound sources with spectra significantly different from those sources listed above. Such sources include machinery, industrial processes, bowling allies, power transformers, musical instruments, many music systems, and transportation noises such as motor vehicles, aircraft and trains. For these sources, accurate assessment of sound transmission requires a detailed analysis in frequency bands. A single-number sound transmission rating for building façade elements is given in Classification E1332.  
4.2 The single-number ratings obtained can be used to compare the potential sound insulation of partitions or floors tested in laboratory conditions (STC) or the actual sound isolation between different suites in buildings (NNIC, NIC). The rating for a partition built and tested in a building may be lower than that obtained for a partition tested in a laboratory because of flanking transmission or construction errors.
Note 1: A similar rating procedure, described in ISO 717, provides single figure sound insulation ratings with a frequency range that extends from 100 to 3150 Hz with no maximum deficiency specified at individual frequencies. For most partitions, the two ratings differ by only one or two points.
SCOPE
1.1 This classification covers methods of calculating single-number acoustical ratings for laboratory and field measurements of sound attenuation obtained in one-third octave bands.  
1.2 The name given to the single-number rating is assigned by the test method that invokes this classification.  
1.3 Test methods that invoke this classification include:  
1.3.1 Test Method E90—The single-number rating is called sound transmission class (STC).  
1.3.2 Test Method E336—Single number ratings are noise isolation class (NIC), normalized noise isolation class (NNIC), apparent sound transmission class (ASTC), and field sound transmission class (FSTC).  
1.3.3 Test Method E596—The single-number rating is called noise isolation class (NIC).  
1.3.4 Test Method E1414—The single-number rating is called ceiling attenuation class (CAC).  
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

SIGNIFICANCE AND USE
5.1 The noise reduction of an enclosure is a property of the enclosure, the location of the sound source used to measure noise reduction, and the space in which the enclosure is placed. It is not a property of the enclosure alone, and its measurement under different conditions can be expected to give different results. When the noise reduction is measured in accordance with this test method, the sound source is outside the enclosure and the sound field outside the enclosure approximates a diffuse sound field. Measurements made in accordance with this test method can be expected to be reproducible from one laboratory to another.  
5.2 The noise reduction measured in accordance with this test method may be used for the following purposes:  
5.2.1 To rank the order of sound-isolating enclosures according to noise isolation class, NIC.  
5.2.2 To estimate the highest one-third octave band sound pressure levels that can occur outside the enclosure without exceeding specified sound pressure levels inside the enclosure.  
5.2.3 To estimate the one-third octave band sound pressure levels that will occur inside the enclosure with specified sound pressure levels outside.  
5.3 The noise reduction measured in accordance with this test method may not estimate accurately the isolation that the enclosure will provide when it is used to isolate a noise source inside it from the space outside. The user should be cautious when using noise reductions measured by this test method to evaluate enclosures used to enclose noise sources.  
5.4 Sound-isolating enclosures are frequently made from prefabricated modular panels. The noise reduction measured by this test method applies to the complete enclosure and not to individual panels from which it is made and cannot be used to infer the sound transmission loss of the individual panels.  
5.5 Specifications for sound-isolating enclosures may include reference to noise reduction and noise isolation class measured in accordance with th...
SCOPE
1.1 This test method covers the reverberation room measurement of the noise reduction of sound-isolating enclosures.  
1.2 The noise isolation class may be determined from the noise reduction measured in accordance with this test method.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
5.1 The main part of this standard uses procedures originally developed for laboratory measurements of the transmission loss of partitions. These procedures assume that the rooms in which the measurements are made have a sound field that reasonably approximates a diffuse field. Sound pressure levels in such rooms are reasonably uniform throughout the room and average levels vary inversely with the logarithm of the room sound absorption. Not all rooms will satisfy these conditions. Practical experience and controlled studies (1)6 have shown that the test method is applicable to smaller spaces normally used for work or living, such as rooms in multi-family dwellings, hotel guest rooms, meeting rooms, and offices with volumes less than 150 cubic meters. The measures appropriate for such spaces are NR, NNR, and ATL. The corresponding single number ratings are NIC, NNIC and ASTC. The ATL and ASTC may be measured between larger spaces that meet a limitation on absorption in the spaces to provide uniform sound distribution.  
5.2 Annex A2 was developed for use in spaces that are very large (volume of 150 m3 or greater). Sound pressure levels during testing can vary markedly across large rooms so that the degree of isolation can vary strongly with distance from the common (separating) partition. This procedure evaluates the isolation observed near the partition. The appropriate measure is NR, and the appropriate single number rating is NIC.  
5.3 It is sometimes necessary to demonstrate that the sound insulation of a partition meets or exceeds a specific criterion. Annex A1 provides additional requirements, and describes how shielding procedures can be used to reduce flanking transmission in stages to show that a partition has achieved a minimum value of the FTL or minimum value of the FSTC which may meet or exceed the criterion. If it is demonstrated that no significant flanking exists through shielding of all potential flanking paths, then, and only then, FTL and FSTC m...
SCOPE
1.1 The sound isolation between two spaces in a building is determined by a combination of the direct transmission through the nominally separating building element (as normally measured in a laboratory) and any transmission along a number of indirect paths, usually referred to as flanking paths. Fig. 1 illustrates the direct paths and some possible structural flanking paths. Additional non-structural flanking paths may include transmission through common air ducts between rooms, or doors to the corridor from adjacent rooms.  
1.2 The main part of this test method defines procedures and metrics to assess the sound isolation between two rooms or portions thereof in a building separated by a common partition including both direct and flanking transmission paths or the apparent sound insulation of the separating partition. Appropriate measures and their single number ratings are the noise reduction (NR) and noise isolation class (NIC), the normalized noise reduction (NNR) and normalized noise isolation class (NNIC), and the apparent transmission loss (ATL) and apparent sound transmission class (ASTC). With the exception of the ATL and ASTC under specified conditions, these procedures in the main part of the test method are only applicable when both room volumes are less than 150 m3.
Note 1: The word “partition” in this test method includes all types of walls, floors, or any other boundaries separating two spaces. The boundaries may be permanent, operable, or movable.  
1.3 The NR and NIC between two locations may always be measured and reported though conditions present will influence how measurements are made. Restrictions such as minimum room volume or dimensions or maximum room absorption are imposed for all other measures and ratings in this standard. Thus, conditions may exist that will not allow NNR (NNIC), ATL (ASTC) or FTL (FSTC) to be measured. Where a partition between rooms is composed of parts that are cons...

SIGNIFICANCE AND USE
5.1 To fully understand the effects of a given treatment, five acoustical factors (transmission loss, acceptance, radiation efficiency, absorption, and damping) must be characterized. For example, only knowing the effect of a given treatment on transmission loss will not allow the acoustical designer or engineer to assess its impacts on propagation of vibration (among other effects), which is an important path to consider for large machinery items and propeller excitation.  
5.2 It is necessary to have a common definition of acoustical performance and test procedure to determine all five acoustical factors for ship’s treatments so that the performance of different treatment types, as well as the same treatment type from different manufacturers, can be compared.  
5.3 In some cases, particularly for damping treatments, the effect of the treatment will be dependent on the non-treated structure’s material and geometry and other non-acoustic factors such as environmental conditions (that is, temperature). To fully characterize a treatment it may be necessary to test a range of base constructions. For reasons of practicality, convenience, or economy, it may be sufficient to test only one to three constructions to achieve an understanding of the material performance in a range of practical situations. Additional discussion is provided in Annex A1.
SCOPE
1.1 This test method covers the laboratory measurement of the acoustical effectiveness of treatments installed on ship bulkheads, decks, and side shells. Measurements are focused on assessing changes in transmission loss, radiation efficiency, and acceptance that occur when treatments are applied. Measurements of changes to absorption and damping are addressed in Appendix X1 and Appendix X2, respectively.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.  
1.4 Any material that is to be installed on a marine division must meet appropriate fire, combustibility, and other applicable SOLAS, USCG, IMO, Navy, or other required non-acoustical standards and specifications. See Appendix X3 for additional information.

SIGNIFICANCE AND USE
5.1 The main part of this standard uses procedures originally developed for laboratory measurements of the transmission loss of partitions. These procedures assume that the rooms in which the measurements are made have a sound field that reasonably approximates a diffuse field. Sound pressure levels in such rooms are reasonably uniform throughout the room and average levels vary inversely with the logarithm of the room sound absorption. Not all rooms will satisfy these conditions. Practical experience and controlled studies (1)6 have shown that the test method is applicable to smaller spaces normally used for work or living, such as rooms in multi-family dwellings, hotel guest rooms, meeting rooms, and offices with volumes less than 150 cubic meters. The measures appropriate for such spaces are NR, NNR, and ATL. The corresponding single number ratings are NIC, NNIC and ASTC. The ATL and ASTC may be measured between larger spaces that meet a limitation on absorption in the spaces to provide uniform sound distribution.  
5.2 Annex A2 was developed for use in spaces that are very large (volume of 150 m3 or greater). Sound pressure levels during testing can vary markedly across large rooms so that the degree of isolation can vary strongly with distance from the common (separating) partition. This procedure evaluates the isolation observed near the partition. The appropriate measure is NR, and the appropriate single number rating is NIC.  
5.3 It is sometimes necessary to demonstrate that the sound insulation of a partition meets or exceeds a specific criterion. Annex A1 provides additional requirements, and describes how shielding procedures can be used to reduce flanking transmission in stages to show that a partition has achieved a minimum value of the FTL or minimum value of the FSTC which may meet or exceed the criterion. If it is demonstrated that no significant flanking exists through shielding of all potential flanking paths, then, and only then, FTL and FSTC m...
SCOPE
1.1 The sound isolation between two spaces in a building is determined by a combination of the direct transmission through the nominally separating building element (as normally measured in a laboratory) and any transmission along a number of indirect paths, usually referred to as flanking paths. Fig. 1 illustrates the direct paths and some possible structural flanking paths. Additional non-structural flanking paths may include transmission through common air ducts between rooms, or doors to the corridor from adjacent rooms.  
1.2 The main part of this test method defines procedures and metrics to assess the sound isolation between two rooms or portions thereof in a building separated by a common partition including both direct and flanking transmission paths or the apparent sound insulation of the separating partition. Appropriate measures and their single number ratings are the noise reduction (NR) and noise isolation class (NIC), the normalized noise reduction (NNR) and normalized noise isolation class (NNIC), and the apparent transmission loss (ATL) and apparent sound transmission class (ASTC). With the exception of the ATL and ASTC under specified conditions, these procedures in the main part of the test method are only applicable when both room volumes are less than 150 m3.
Note 1: The word “partition” in this test method includes all types of walls, floors, or any other boundaries separating two spaces. The boundaries may be permanent, operable, or movable.  
1.3 The NR and NIC between two locations may always be measured and reported though conditions present will influence how measurements are made. Restrictions such as minimum room volume or dimensions or maximum room absorption are imposed for all other measures and ratings in this standard. Thus, conditions may exist that will not allow NNR (NNIC), ATL (ASTC) or FTL (FSTC) to be measured. Where a partition between rooms is composed of parts that are cons...

SIGNIFICANCE AND USE
5.1 To fully understand the effects of a given treatment, five acoustical factors (transmission loss, acceptance, radiation efficiency, absorption, and damping) must be characterized. For example, only knowing the effect of a given treatment on transmission loss will not allow the acoustical designer or engineer to assess its impacts on propagation of vibration (among other effects), which is an important path to consider for large machinery items and propeller excitation.  
5.2 It is necessary to have a common definition of acoustical performance and test procedure to determine all five acoustical factors for ship’s treatments so that the performance of different treatment types, as well as the same treatment type from different manufacturers, can be compared.  
5.3 In some cases, particularly for damping treatments, the effect of the treatment will be dependent on the non-treated structure’s material and geometry and other non-acoustic factors such as environmental conditions (that is, temperature). To fully characterize a treatment it may be necessary to test a range of base constructions. For reasons of practicality, convenience, or economy, it may be sufficient to test only one to three constructions to achieve an understanding of the material performance in a range of practical situations. Additional discussion is provided in Annex A1.
SCOPE
1.1 This test method covers the laboratory measurement of the acoustical effectiveness of treatments installed on ship bulkheads, decks, and side shells. Measurements are focused on assessing changes in transmission loss, radiation efficiency, and acceptance that occur when treatments are applied. Measurements of changes to absorption and damping are addressed in Appendix X1 and Appendix X2, respectively.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.  
1.4 Any material that is to be installed on a marine division must meet appropriate fire, combustibility, and other applicable SOLAS, USCG, IMO, Navy, or other required non-acoustical standards and specifications. See Appendix X3 for additional information.

SIGNIFICANCE AND USE
5.1 The spectrum of the noise produced in the receiving room by the standard tapping machine is determined by (1) the size and the mechanical properties of the floor-ceiling assembly, such as its weight, surface properties, mounting or edge restraints, stiffness, and internal damping; (2)  the degree of flanking transmission through associated structures; and (3) the acoustical response of the receiving room.  
5.2 The standardized tapping machine specified in 6.1.1 produces a continuous series of uniform impacts at a uniform rate on a floor-ceiling assembly to allow accurate and reproducible measurements of impact sound pressure levels in the receiving room. The tapping machine is not designed to simulate any one type of impact, such as male or female footsteps or to simulate the weight of a human walker. Also, measurements described in this method and ratings based on the results are restricted to a specific frequency range. Thus the subjectively annoying creak or boom generated by human footfalls on a limber floor-ceiling assembly may not be adequately evaluated by this test method.  
5.3 Laboratory Test Method E492 calls for highly diffuse sound fields and the suppression of flanking sound transmission in the laboratory’s receiving room. This field test method does not allow efforts to suppress flanking. In field tests, acoustical measurements are much more uncertain than in the laboratory since a great variety of receiving room shapes and sizes are encountered in ordinary buildings. Highly diffuse fields are seldom found and the nature of structure-borne flanking transmission can vary widely. In addition, energy can be transmitted laterally away from the receiving room. The amount of lateral transmission of energy can vary significantly between buildings. Consequently, good agreement between laboratory tests and field tests on similar floor-ceiling assemblies should not be expected.  
5.4 Several metrics are available for specific uses:  
5.4.1 absorption n...
SCOPE
1.1 This test method covers the measurement of the transmission of impact sound generated by a standard tapping machine through floor-ceiling assemblies and associated supporting structures in field situations.  
1.2 Measurements may be conducted on all types of floor-ceiling assemblies, including those with floating-floor or suspended ceiling elements, or both, and floor-ceiling assemblies surfaced with any type of floor-surfacing or floor-covering materials.  
1.3 This test method defines several procedures and metrics to assess either the apparent performance of the nominally separating floor-ceiling or the isolation of a receiving room from the sound produced by the operation of the tapping machine. The receiving room may be the space directly below the tapping machine or, in some cases, any separated space that receives sound from the operation of the tapping machine. The source and receiving rooms as well as the floor-ceiling system are identified and described in the test report. All measured levels and derivative single number ratings include the effect of flanking transmission. Efforts to suppress flanking are not permitted. Available measures and their single number ratings are the impact sound pressure levels (ISPL) and impact sound rating (ISR), the reverberation time normalized impact sound pressure levels (RTNISPL) and normalized impact sound rating (NISR), and the absorption normalized impact sound pressure levels (ANISPL) and apparent impact insulation class (AIIC).  
1.4 The ISPL and ISR may be measured and reported between any two specific rooms or usage areas where the source room area is large enough to accommodate the tapping machine positions and the receiving room volume is sufficiently large to accommodate the microphone positions. For all other measures and ratings in this standard, restrictions such as minimum room volume or dimensions or maximum room absorption are imposed. Thus, conditions ...

SIGNIFICANCE AND USE
5.1 This standard provides a method for testing the apparent sound insulating properties of doors in the field originally proposed by Morin (1).6 This allows doors to be evaluated with a result that has been found to be similar to the transmission loss.  
5.2 The results of this measurement are the normalized door insertion loss, NDIL, at individual frequencies, and the single number rating door transmission class, DTC. The insertion loss is normalized by the small change in sound level which occurs on the source side when the door is opened and closed.  
5.3 Comparative measurements using this method and the method of Test Method E90 on the same door installations in a laboratory indicate good agreement between the transmission loss and normalized door insertion loss. See Appendix X1 and Ref (2).  
5.4 The fixed-microphone and scanning methods have been compared in the field. See Appendix X2.
SCOPE
1.1 The sound insulation properties of a door are measured in a laboratory as the sound transmission loss in accordance with Test Method E90. Using those data single number rating sound transmission class (STC) is assigned. In the field, the rooms on one or both sides of a partition containing a door are often either too small or too large and absorptive to allow the apparent transmission loss (ATL) of the partition-door assembly to be measured. Even if that is not the case, the result measured is the composite ATL of the partition including the door, and not that of the door itself. Test Method E336 actually states that it is impossible to measure the ATL of a portion of a partition such as a door according to the procedures of that standard. This test method provides a method of evaluating doors in such cases using a normalized insertion loss with a resulting single number rating door transmission class, DTC. This method is intended primarily for hinged personnel doors with latching mechanisms and is limited to door openings of area less than 6 m2. The flanking effects of surrounding structure are reduced compared to E336 but not completely eliminated. In a laboratory environment, the DTC is close to or equal to the STC of the door, but in the field results less than the laboratory STC should be expected.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
5.1 This standard provides a method for testing the apparent sound insulating properties of doors in the field originally proposed by Morin (1).6 This allows doors to be evaluated with a result that has been found to be similar to the transmission loss.  
5.2 The results of this measurement are the normalized door insertion loss, NDIL, at individual frequencies, and the single number rating door transmission class, DTC. The insertion loss is normalized by the small change in sound level which occurs on the source side when the door is opened and closed.  
5.3 Comparative measurements using this method and the method of Test Method E90 on the same door installations in a laboratory indicate good agreement between the transmission loss and normalized door insertion loss. See Appendix X1 and Ref (2).  
5.4 The fixed-microphone and scanning methods have been compared in the field. See Appendix X2.
SCOPE
1.1 The sound insulation properties of a door are measured in a laboratory as the sound transmission loss in accordance with Test Method E90. Using those data single number rating sound transmission class (STC) is assigned. In the field, the rooms on one or both sides of a partition containing a door are often either too small or too large and absorptive to allow the apparent transmission loss (ATL) of the partition-door assembly to be measured. Even if that is not the case, the result measured is the composite ATL of the partition including the door, and not that of the door itself. Test Method E336 actually states that it is impossible to measure the ATL of a portion of a partition such as a door according to the procedures of that standard. This test method provides a method of evaluating doors in such cases using a normalized insertion loss with a resulting single number rating door transmission class, DTC. This method is intended primarily for hinged personnel doors with latching mechanisms and is limited to door openings of area less than 6 m2. The flanking effects of surrounding structure are reduced compared to E336 but not completely eliminated. In a laboratory environment, the DTC is close to or equal to the STC of the door, but in the field results less than the laboratory STC should be expected.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
5.1 The main part of this standard uses procedures originally developed for laboratory measurements of the transmission loss of partitions. These procedures assume that the rooms in which the measurements are made have a sound field that reasonably approximates a diffuse field. Sound pressure levels in such rooms are reasonably uniform throughout the room and average levels vary inversely with the logarithm of the room sound absorption. Not all rooms will satisfy these conditions. Practical experience and controlled studies (1)6 have shown that the test method is applicable to smaller spaces normally used for work or living, such as rooms in multi-family dwellings, hotel guest rooms, meeting rooms, and offices with volumes less than 150 cubic meters. The measures appropriate for such spaces are NR, NNR, and ATL. The corresponding single number ratings are NIC, NNIC and ASTC. The ATL and ASTC may be measured between larger spaces that meet a limitation on absorption in the spaces to provide uniform sound distribution.  
5.2 Annex A2 was developed for use in spaces that are very large (volume of 150 m3 or greater). Sound pressure levels during testing can vary markedly across large rooms so that the degree of isolation can vary strongly with distance from the common (separating) partition. This procedure evaluates the isolation observed near the partition. The appropriate measure is NR, and the appropriate single number rating is NIC.  
5.3 It is sometimes necessary to demonstrate that the sound insulation of a partition meets or exceeds a specific criterion. Annex A1 provides additional requirements, and describes how shielding procedures can be used to reduce flanking transmission in stages to show that a partition has achieved a minimum value of the FTL or minimum value of the FSTC which may meet or exceed the criterion. If it is demonstrated that no significant flanking exists through shielding of all potential flanking paths, then, and only then, FTL and FSTC m...
SCOPE
1.1 The sound isolation between two spaces in a building is determined by a combination of the direct transmission through the nominally separating building element (as normally measured in a laboratory) and any transmission along a number of indirect paths, usually referred to as flanking paths. Fig. 1 illustrates the direct paths and some possible structural flanking paths. Additional non-structural flanking paths may include transmission through common air ducts between rooms, or doors to the corridor from adjacent rooms.  
1.2 The main part of this test method defines procedures and metrics to assess the sound isolation between two rooms or portions thereof in a building separated by a common partition including both direct and flanking transmission paths or the apparent sound insulation of the separating partition. Appropriate measures and their single number ratings are the noise reduction (NR) and noise isolation class (NIC), the normalized noise reduction (NNR) and normalized noise isolation class (NNIC), and the apparent transmission loss (ATL) and apparent sound transmission class (ASTC). With the exception of the ATL and ASTC under specified conditions, these procedures in the main part of the test method are only applicable when both room volumes are less than 150 m3.
Note 1: The word “partition” in this test method includes all types of walls, floors, or any other boundaries separating two spaces. The boundaries may be permanent, operable, or movable.  
1.3 The NR and NIC between two locations may always be measured and reported though conditions present will influence how measurements are made. Restrictions such as minimum room volume or dimensions or maximum room absorption are imposed for all other measures and ratings in this standard. Thus, conditions may exist that will not allow NNR (NNIC), ATL (ASTC) or FTL (FSTC) to be measured. Where a partition between rooms is composed of parts that are const...

SIGNIFICANCE AND USE
5.1 The spectrum of the noise produced in the receiving room by the standard tapping machine is determined by (1) the size and the mechanical properties of the floor-ceiling assembly, such as its weight, surface properties, mounting or edge restraints, stiffness, and internal damping; (2)  the degree of flanking transmission through associated structures; and (3) the acoustical response of the receiving room.  
5.2 The standardized tapping machine specified in 6.1.1 produces a continuous series of uniform impacts at a uniform rate on a floor-ceiling assembly to allow accurate and reproducible measurements of impact sound pressure levels in the receiving room. The tapping machine is not designed to simulate any one type of impact, such as male or female footsteps or to simulate the weight of a human walker. Also, measurements described in this method and ratings based on the results are restricted to a specific frequency range. Thus the subjectively annoying creak or boom generated by human footfalls on a limber floor-ceiling assembly may not be adequately evaluated by this test method.  
5.3 Laboratory Test Method E492 calls for highly diffuse sound fields and the suppression of flanking sound transmission in the laboratory’s receiving room. This field test method does not allow efforts to suppress flanking. In field tests, acoustical measurements are much more uncertain than in the laboratory since a great variety of receiving room shapes and sizes are encountered in ordinary buildings. Highly diffuse fields are seldom found and the nature of structure-borne flanking transmission can vary widely. In addition, energy can be transmitted laterally away from the receiving room. The amount of lateral transmission of energy can vary significantly between buildings. Consequently, good agreement between laboratory tests and field tests on similar floor-ceiling assemblies should not be expected.  
5.4 Several metrics are available for specific uses:  
5.4.1 absorption n...
SCOPE
1.1 This test method covers the measurement of the transmission of impact sound generated by a standard tapping machine through floor-ceiling assemblies and associated supporting structures in field situations.  
1.2 Measurements may be conducted on all types of floor-ceiling assemblies, including those with floating-floor or suspended ceiling elements, or both, and floor-ceiling assemblies surfaced with any type of floor-surfacing or floor-covering materials.  
1.3 This test method defines several procedures and metrics to assess either the apparent performance of the nominally separating floor-ceiling or the isolation of a receiving room from the sound produced by the operation of the tapping machine. The receiving room may be the space directly below the tapping machine or, in some cases, any separated space that receives sound from the operation of the tapping machine. The source and receiving rooms as well as the floor-ceiling system are identified and described in the test report. All measured levels and derivative single number ratings include the effect of flanking transmission. Efforts to suppress flanking are not permitted. Available measures and their single number ratings are the impact sound pressure levels (ISPL) and impact sound rating (ISR), the reverberation time normalized impact sound pressure levels (RTNISPL) and normalized impact sound rating (NISR), and the absorption normalized impact sound pressure levels (ANISPL) and apparent impact insulation class (AIIC).  
1.4 The ISPL and ISR may be measured and reported between any two specific rooms or usage areas where the source room area is large enough to accommodate the tapping machine positions and the receiving room volume is sufficiently large to accommodate the microphone positions. For all other measures and ratings in this standard, restrictions such as minimum room volume or dimensions or maximum room absorption are imposed. Thus, conditions ...

SIGNIFICANCE AND USE
5.1 The spectrum of the noise produced in the receiving room by the standard tapping machine is determined by (1) the size and the mechanical properties of the floor-ceiling assembly, such as its weight, surface properties, mounting or edge restraints, stiffness, and internal damping; (2)  the degree of flanking transmission through associated structures; and (3) the acoustical response of the receiving room.  
5.2 The standardized tapping machine specified in 6.1.1 produces a continuous series of uniform impacts at a uniform rate on a floor-ceiling assembly to allow accurate and reproducible measurements of impact sound pressure levels in the receiving room. The tapping machine is not designed to simulate any one type of impact, such as male or female footsteps or to simulate the weight of a human walker. Also, measurements described in this method and ratings based on the results are restricted to a specific frequency range. Thus the subjectively annoying creak or boom generated by human footfalls on a limber floor-ceiling assembly may not be adequately evaluated by this test method.  
5.3 Laboratory Test Method E492 calls for highly diffuse sound fields and the suppression of flanking sound transmission in the laboratory’s receiving room. This field test method does not allow efforts to suppress flanking. In field tests, acoustical measurements are much more uncertain than in the laboratory since a great variety of receiving room shapes and sizes are encountered in ordinary buildings. Highly diffuse fields are seldom found and the nature of structure-borne flanking transmission can vary widely. In addition, energy can be transmitted laterally away from the receiving room. The amount of lateral transmission of energy can vary significantly between buildings. Consequently, good agreement between laboratory tests and field tests on similar floor-ceiling assemblies should not be expected.  
5.4 Several metrics are available for specific uses:  
5.4.1 absorption n...
SCOPE
1.1 This test method covers the measurement of the transmission of impact sound generated by a standard tapping machine through floor-ceiling assemblies and associated supporting structures in field situations.  
1.2 Measurements may be conducted on all types of floor-ceiling assemblies, including those with floating-floor or suspended ceiling elements, or both, and floor-ceiling assemblies surfaced with any type of floor-surfacing or floor-covering materials.  
1.3 This test method defines several procedures and metrics to assess either the apparent performance of the nominally separating floor-ceiling or the isolation of a receiving room from the sound produced by the operation of the tapping machine. The receiving room may be the space directly below the tapping machine or, in some cases, any separated space that receives sound from the operation of the tapping machine. The source and receiving rooms as well as the floor-ceiling system are identified and described in the test report. All measured levels and derivative single number ratings include the effect of flanking transmission. Efforts to suppress flanking are not permitted. Available measures and their single number ratings are the impact sound pressure levels (ISPL) and impact sound rating (ISR), the reverberation time normalized impact sound pressure levels (RTNISPL) and normalized impact sound rating (NISR), and the absorption normalized impact sound pressure levels (ANISPL) and apparent impact insulation class (AIIC).  
1.4 The ISPL and ISR may be measured and reported between any two specific rooms or usage areas where the source room area is large enough to accommodate the tapping machine positions and the receiving room volume is sufficiently large to accommodate the microphone positions. For all other measures and ratings in this standard, restrictions such as minimum room volume or dimensions or maximum room absorption are imposed. Thus, conditions ...

SIGNIFICANCE AND USE
5.1 The spectrum of the noise produced in the receiving room by the standard tapping machine is determined by (1) the size and the mechanical properties of the floor-ceiling assembly, such as its weight, surface properties, mounting or edge restraints, stiffness, and internal damping; (2)  the degree of flanking transmission through associated structures; and (3) the acoustical response of the receiving room.  
5.2 The standardized tapping machine specified in 6.1.1 produces a continuous series of uniform impacts at a uniform rate on a floor-ceiling assembly to allow accurate and reproducible measurements of impact sound pressure levels in the receiving room. The tapping machine is not designed to simulate any one type of impact, such as male or female footsteps or to simulate the weight of a human walker. Also, measurements described in this method and ratings based on the results are restricted to a specific frequency range. Thus the subjectively annoying creak or boom generated by human footfalls on a limber floor-ceiling assembly may not be adequately evaluated by this test method.  
5.3 Laboratory Test Method E492 calls for highly diffuse sound fields and the suppression of flanking sound transmission in the laboratory’s receiving room. This field test method does not allow efforts to suppress flanking. In field tests, acoustical measurements are much more uncertain than in the laboratory since a great variety of receiving room shapes and sizes are encountered in ordinary buildings. Highly diffuse fields are seldom found and the nature of structure-borne flanking transmission can vary widely. In addition, energy can be transmitted laterally away from the receiving room. The amount of lateral transmission of energy can vary significantly between buildings. Consequently, good agreement between laboratory tests and field tests on similar floor-ceiling assemblies should not be expected.  
5.4 Several metrics are available for specific uses:  
5.4.1 absorption n...
SCOPE
1.1 This test method covers the measurement of the transmission of impact sound generated by a standard tapping machine through floor-ceiling assemblies and associated supporting structures in field situations.  
1.2 Measurements may be conducted on all types of floor-ceiling assemblies, including those with floating-floor or suspended ceiling elements, or both, and floor-ceiling assemblies surfaced with any type of floor-surfacing or floor-covering materials.  
1.3 This test method defines several procedures and metrics to assess either the apparent performance of the nominally separating floor-ceiling or the isolation of a receiving room from the sound produced by the operation of the tapping machine. The receiving room may be the space directly below the tapping machine or, in some cases, any separated space that receives sound from the operation of the tapping machine. The source and receiving rooms as well as the floor-ceiling system are identified and described in the test report. All measured levels and derivative single number ratings include the effect of flanking transmission. Efforts to suppress flanking are not permitted. Available measures and their single number ratings are the impact sound pressure levels (ISPL) and impact sound rating (ISR), the reverberation time normalized impact sound pressure levels (RTNISPL) and normalized impact sound rating (NISR), and the absorption normalized impact sound pressure levels (ANISPL) and apparent impact insulation class (AIIC).  
1.4 The ISPL and ISR may be measured and reported between any two specific rooms or usage areas where the source room area is large enough to accommodate the tapping machine positions and the receiving room volume is sufficiently large to accommodate the microphone positions. For all other measures and ratings in this standard, restrictions such as minimum room volume or dimensions or maximum room absorption are imposed. Thus, conditions ...

SIGNIFICANCE AND USE
Modern offices and other multipurpose buildings commonly have suspended acoustical ceilings installed over room dividing partitions. The test facility prescribed in this test method is useful for providing ceiling attenuation data on the relevant ceiling/partition elements and systems, to ensure that the transmission of sound through the ceiling and plenum space, or through the combination of ceiling, plenum space, and partition systems, provides a suitable degree of acoustical isolation.
This test method is useful for rating and specifying, under standardized conditions, the sound attenuation performance of ceiling materials when mounted in a specified suspension system.
This test method may be useful for selecting a wall-ceiling system for probable compliance with a performance specification for overall sound isolation between rooms. However, the actual field performance may differ significantly, particularly if the field plenum depth is not within the limits specified in this test method or if the plenum space contains large ducts, beams, etc., or both. (See Test Method E336.)
The flexibility inherent in the test facility enables evaluation of the effects of penetrations, induced leakage paths, luminaire, and air diffuser installations and discontinuities in the ceiling suspension system at the partition line, including penetration of the partition into the ceiling plenum. The effect of installing plenum barriers at the partition line may also be investigated.
With the concentration of sound absorbent area offered by a suspended sound absorbent ceiling installed in a room, it is not possible to obtain a good approximation to a diffuse sound field in that room. The plenum dimensions prevent the maintenance of a diffuse sound field above the test specimen. These factors affect the values of the measured ceiling sound attenuation and thus the measurements are not a fundamental property of the ceiling. The test method measures the acoustical properties attain...
SCOPE
1.1 This test method utilizes a laboratory space so arranged that it simulates a pair of horizontally adjacent small offices or rooms separated by a partition and sharing a common plenum space. The partition either extends to the underside of a common plenum space or penetrates through it. In the prescribed configuration, special design features of the facility ensure that the only significant sound transmission path is by way of the ceiling and the plenum space
1.2 Within the limitations outlined in the significance statement, the primary quantity measured by this test method is the ceiling attenuation of a suspended ceiling installed in a laboratory environment. By accounting for receiving room sound absorption, the normalized ceiling attenuation may be determined.
1.3 The test method may also be used to evaluate the attenuation of composite ceiling systems comprised of the ceiling material and other components such as luminaires and ventilating systems.
1.4 The field performance of a ceiling system may differ significantly from the results obtained by this test method (see Section 5, Significance and Use, and Test Method E336).
1.5 The procedures may also be used to study the additional sound insulation that may be achieved by other attenuation measures. This would include materials used either as plenum barriers or as backing for all or part of the ceiling.
1.6 The facility may also be used to study the performance of an integrated system comprising plenum, ceiling, and partition, tested as a single assembly.
1.7 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
1.8 This standard does not purport to address all of the safety concerns, if any, ...

SIGNIFICANCE AND USE
5.1 Modern offices and other multipurpose buildings commonly have suspended acoustical ceilings installed over room dividing partitions. The test facility prescribed in this test method is useful for providing ceiling attenuation data on the relevant ceiling/partition elements and systems, to ensure that the transmission of sound through the ceiling and plenum space, or through the combination of ceiling, plenum space, and partition systems, provides a suitable degree of acoustical isolation.  
5.2 This test method is useful for rating and specifying, under standardized conditions, the sound attenuation performance of ceiling materials when mounted in a specified suspension system.  
5.3 This test method may be useful for selecting a wall-ceiling system for probable compliance with a performance specification for overall sound isolation between rooms. However, the actual field performance may differ significantly, particularly if the field plenum depth is not within the limits specified in this test method or if the plenum space contains large ducts, beams, etc., or both. (See Test Method E336.)  
5.4 The flexibility inherent in the test facility enables evaluation of the effects of penetrations, induced leakage paths, luminaire, and air diffuser installations and discontinuities in the ceiling suspension system at the partition line, including penetration of the partition into the ceiling plenum. The effect of installing plenum barriers at the partition line may also be investigated.  
5.5 With the concentration of sound absorbent area offered by a suspended sound absorbent ceiling installed in a room, it is not possible to obtain a good approximation to a diffuse sound field in that room. The plenum dimensions prevent the maintenance of a diffuse sound field above the test specimen. These factors affect the values of the measured ceiling sound attenuation and thus the measurements are not a fundamental property of the ceiling. The test method measures the acou...
SCOPE
1.1 This test method utilizes a laboratory space so arranged that it simulates a pair of horizontally adjacent small offices or rooms separated by a partition and sharing a common plenum space. The partition either extends to the underside of a common plenum space or penetrates through it. In the prescribed configuration, special design features of the facility ensure that the only significant sound transmission path is by way of the ceiling and the plenum space.  
1.2 Within the limitations outlined in the significance statement, the primary quantity measured by this test method is the ceiling attenuation of a suspended ceiling installed in a laboratory environment. By accounting for receiving room sound absorption, the normalized ceiling attenuation may be determined.  
1.3 The test method may also be used to evaluate the attenuation of composite ceiling systems comprised of the ceiling material and other components such as luminaires and ventilating systems.  
1.4 The field performance of a ceiling system may differ significantly from the results obtained by this test method (see Section 5, Significance and Use, and Test Method E336).  
1.5 The procedures may also be used to study the additional sound insulation that may be achieved by other attenuation measures. This would include materials used either as plenum barriers or as backing for all or part of the ceiling.  
1.6 The facility may also be used to study the performance of an integrated system comprising plenum, ceiling, and partition, tested as a single assembly.  
1.7 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.  
1.8 This standard does not purport to address all of the safety concerns, ...

SIGNIFICANCE AND USE
The main part of this standard uses procedures originally developed for laboratory measurements of the transmission loss of partitions. These procedures assume that the rooms in which the measurements are made have a sound field that reasonably approximates a diffuse field. Sound pressure levels in such rooms are reasonably uniform throughout the room and average levels vary inversely with the logarithm of the room sound absorption. Not all rooms will satisfy these conditions. Practical experience and controlled studies (1) have shown that the test method is applicable to smaller spaces normally used for work or living, such as rooms in multi-family dwellings, hotel guest rooms, meeting rooms, and offices with volumes less than 150 cubic meters. The measures appropriate for such spaces are NR, NNR, and ATL. The corresponding single number ratings are NIC, NNIC and ASTC. The ATL and ASTC may be measured between larger spaces that meet a limitation on absorption in the spaces to provide uniform sound distribution.
Annex A2 was developed for use in spaces that are very large (volume of 150 m3 or greater). Sound pressure levels during testing can vary markedly across large rooms so that the degree of isolation can vary strongly with distance from the common (separating) partition. This procedure evaluates the isolation observed near the partition. The appropriate measure is NR, and the appropriate single number rating is NIC.
It is sometimes necessary to demonstrate that the sound insulation of a partition meets or exceeds a specific criterion. Annex A1 provides additional requirements, and describes how shielding procedures can be used to reduce flanking transmission in stages to show that a partition has achieved a minimum value of the FTL or minimum value of the FSTC which may meet or exceed the criterion. If it is demonstrated that no significant flanking exists through shielding of all potential flanking paths, then, and only then, FTL and FSTC may be reported ...
SCOPE
1.1 The sound isolation between two spaces in a building is determined by a combination of the direct transmission through the nominally separating building element (as normally measured in a laboratory) and any transmission along a number of indirect paths, usually referred to as flanking paths. Fig. 1 illustrates the direct paths and some possible structural flanking paths. Additional non-structural flanking paths may include transmission through common air ducts between rooms, or doors to the corridor from adjacent rooms.
1.2 The main part of this test method defines procedures and metrics to assess the sound isolation between two rooms or portions thereof in a building separated by a common partition including both direct and flanking transmission paths or the apparent sound insulation of the separating partition. Appropriate measures and their single number ratings are the noise reduction (NR) and noise isolation class (NIC), the normalized noise reduction (NNR) and normalized noise isolation class (NNIC), and the apparent transmission loss (ATL) and apparent sound transmission class (ASTC). With the exception of the ATL and ASTC under specified conditions, these procedures in the main part of the test method are only applicable when both room volumes are less than 150 m3.
Note 1—The word “partition” in this test method includes all types of walls, floors, or any other boundaries separating two spaces. The boundaries may be permanent, operable, or movable.
1.3 Annex A1 provides methods to assess the sound transmission through a partition or partition element with the influence of flanking transmission reduced. These methods may be used when it must be demonstrated that a partition has achieved a specified minimum sound attenuation. The results are the field transmission loss (FTL) and field sound transmission class (FSTC).
1.4 Annex A2 provides methods to measure the sound isolation between portions of two ...

SIGNIFICANCE AND USE
Modern offices and other multipurpose buildings commonly have suspended acoustical ceilings installed over room dividing partitions. The test facility prescribed in this test method is useful for providing ceiling attenuation data on the relevant ceiling/partition elements and systems, to ensure that the transmission of sound through the ceiling and plenum space, or through the combination of ceiling, plenum space, and partition systems, provides a suitable degree of acoustical isolation.
This test method is useful for rating and specifying, under standardized conditions, the sound attenuation performance of ceiling materials when mounted in a specified suspension system.
This test method may be useful for selecting a wall-ceiling system for probable compliance with a performance specification for overall sound isolation between rooms. However, the actual field performance may differ significantly, particularly if the field plenum depth is not within the limits specified in this test method or if the plenum space contains large ducts, beams, etc., or both. (See Test Method E336.)
The flexibility inherent in the test facility enables evaluation of the effects of penetrations, induced leakage paths, luminaire, and air diffuser installations and discontinuities in the ceiling suspension system at the partition line, including penetration of the partition into the ceiling plenum. The effect of installing plenum barriers at the partition line may also be investigated.
With the concentration of sound absorbent area offered by a suspended sound absorbent ceiling installed in a room, it is not possible to obtain a good approximation to a diffuse sound field in that room. The plenum dimensions prevent the maintenance of a diffuse sound field above the test specimen. These factors affect the values of the measured ceiling sound attenuation and thus the measurements are not a fundamental property of the ceiling. The test method measures the acoustical properties attain...
SCOPE
1.1 This test method utilizes a laboratory space so arranged that it simulates a pair of horizontally adjacent small offices or rooms separated by a partition and sharing a common plenum space. The partition either extends to the underside of a common plenum space or penetrates through it. In the prescribed configuration, special design features of the facility ensure that the only significant sound transmission path is by way of the ceiling and the plenum space
1.2 Within the limitations outlined in the significance statement, the primary quantity measured by this test method is the ceiling attenuation of a suspended ceiling installed in a laboratory environment. By accounting for receiving room sound absorption, the normalized ceiling attenuation may be determined.
1.3 The test method may also be used to evaluate the attenuation of composite ceiling systems comprised of the ceiling material and other components such as luminaires and ventilating systems.
1.4 The field performance of a ceiling system may differ significantly from the results obtained by this test method (see Section 5, Significance and Use, and Test Method E336).
1.5 The procedures may also be used to study the additional sound insulation that may be achieved by other attenuation measures. This would include materials used either as plenum barriers or as backing for all or part of the ceiling.
1.6 The facility may also be used to study the performance of an integrated system comprising plenum, ceiling, and partition, tested as a single assembly.
1.7 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
1.8 This standard does not purport to address all of the safety concerns, if any, ...

SIGNIFICANCE AND USE
The spectrum of the noise produced in the receiving room by the standard tapping machine is determined by (1) the size and the mechanical properties of the floor-ceiling assembly, such as its weight, surface properties, mounting or edge restraints, stiffness, and internal damping; (2) the degree of flanking transmission through associated structures; and (3) the acoustical response of the receiving room.  
The standardized tapping machine specified in 6.1.1 produces a continuous series of uniform impacts at a uniform rate on a floor-ceiling assembly to allow accurate and reproducible measurements of impact sound pressure levels in the receiving room. The tapping machine is not designed to simulate any one type of impact, such as male or female footsteps or to simulate the weight of a human walker. Also, measurements described in this method and ratings based on the results are restricted to a specific frequency range. Thus the subjectively annoying creak or boom generated by human footfalls on a limber floor-ceiling assembly may not be adequately evaluated by this test method.
Laboratory Test Method E492 calls for highly diffuse sound fields and the suppression of flanking sound transmission in the laboratory’s receiving room. This field test method does not allow efforts to suppress flanking. In field tests, acoustical measurements are much more uncertain than in the laboratory since a great variety of receiving room shapes and sizes are encountered in ordinary buildings. Highly diffuse fields are seldom found and the nature of structure-borne flanking transmission can vary widely; consequently, good agreement between laboratory tests and field tests on similar floor-ceiling assemblies should not be expected.
SCOPE
1.1 This test method covers the measurement of the transmission of impact sound generated by a standard tapping machine through floor-ceiling assemblies and associated supporting structures in field situations.  
1.2 Measurements may be conducted on all types of floor-ceiling assemblies, including those with floating-floor or suspended ceiling elements, or both, and floor-ceiling assemblies surfaced with any type of floor-surfacing or floor-covering materials.
1.3 This test method defines several procedures and metrics to assess either the apparent performance of the nominally separating floor-ceiling or the isolation of a receiving room from the sound produced by the operation of the tapping machine. The receiving room may be the space directly below the tapping machine or, in some cases, any separated space that receives sound from the operation of the tapping machine. The source and receiving rooms as well as the floor-ceiling system are identified and described in the test report. All measured levels and derivative single number ratings include the effect of flanking transmission. Efforts to suppress flanking are not permitted. Available measures and their single number ratings are the impact sound pressure levels (ISPL) and impact sound rating (ISR), the reverberation time normalized impact sound pressure levels (RTNISPL) and normalized impact sound rating (NISR), and the absorption normalized impact sound pressure levels (ANISPL) and apparent impact insulation class (AIIC).
1.4 The text of this standard references notes and footnotes which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the standard.
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
The spectrum of the noise produced in the receiving room by the standard tapping machine is determined by (1) the size and the mechanical properties of the floor-ceiling assembly, such as its weight, surface properties, mounting or edge restraints, stiffness, and internal damping; (2) the degree of flanking transmission through associated structures; and (3) the acoustical response of the receiving room.  
The standardized tapping machine specified in 6.1.1 produces a continuous series of uniform impacts at a uniform rate on a floor-ceiling assembly to allow accurate and reproducible measurements of impact sound pressure levels in the receiving room. The tapping machine is not designed to simulate any one type of impact, such as male or female footsteps or to simulate the weight of a human walker. Also, measurements described in this method and ratings based on the results are restricted to a specific frequency range. Thus the subjectively annoying creak or boom generated by human footfalls on a limber floor-ceiling assembly may not be adequately evaluated by this test method.
Laboratory Test Method E492 calls for highly diffuse sound fields and the suppression of flanking sound transmission in the laboratory’s receiving room. This field test method does not allow efforts to suppress flanking. In field tests, acoustical measurements are much more uncertain than in the laboratory since a great variety of receiving room shapes and sizes are encountered in ordinary buildings. Highly diffuse fields are seldom found and the nature of structure-borne flanking transmission can vary widely; consequently, good agreement between laboratory tests and field tests on similar floor-ceiling assemblies should not be expected.
Several metrics are available for specific uses:
absorption normalized impact sound pressure level (ANISPL) and apparent impact insulation class (AIIC)—These metrics are intended to evaluate the performance of the floor-ceiling assembly and adjacent st...
SCOPE
1.1 This test method covers the measurement of the transmission of impact sound generated by a standard tapping machine through floor-ceiling assemblies and associated supporting structures in field situations.  
1.2 Measurements may be conducted on all types of floor-ceiling assemblies, including those with floating-floor or suspended ceiling elements, or both, and floor-ceiling assemblies surfaced with any type of floor-surfacing or floor-covering materials.
1.3 This test method defines several procedures and metrics to assess either the apparent performance of the nominally separating floor-ceiling or the isolation of a receiving room from the sound produced by the operation of the tapping machine. The receiving room may be the space directly below the tapping machine or, in some cases, any separated space that receives sound from the operation of the tapping machine. The source and receiving rooms as well as the floor-ceiling system are identified and described in the test report. All measured levels and derivative single number ratings include the effect of flanking transmission. Efforts to suppress flanking are not permitted. Available measures and their single number ratings are the impact sound pressure levels (ISPL) and impact sound rating (ISR), the reverberation time normalized impact sound pressure levels (RTNISPL) and normalized impact sound rating (NISR), and the absorption normalized impact sound pressure levels (ANISPL) and apparent impact insulation class (AIIC).
1.4 The text of this standard references notes and footnotes which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the standard.
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.6 This standard does not purport to address all of the safety concerns, if any, associated ...

SIGNIFICANCE AND USE
The main part of this standard uses procedures originally developed for laboratory measurements of the transmission loss of partitions. These procedures assume that the rooms in which the measurements are made have a sound field that reasonably approximates a diffuse field. Sound pressure levels in such rooms are reasonably uniform throughout the room and average levels vary inversely with the logarithm of the room sound absorption. Not all rooms will satisfy these conditions. Practical experience and controlled studies (1) have shown that the test method is applicable to smaller spaces normally used for work or living, such as rooms in multi-family dwellings, hotel guest rooms, meeting rooms, and offices with volumes less than 150 cubic meters. The measures appropriate for such spaces are NR, NNR, and ATL. The corresponding single number ratings are NIC, NNIC and ASTC. The ATL and ASTC may be measured between larger spaces that meet a limitation on absorption in the spaces to provide uniform sound distribution.
Annex A2 was developed for use in spaces that are very large (volume of 150 m3 or greater). Sound pressure levels during testing can vary markedly across large rooms so that the degree of isolation can vary strongly with distance from the common (separating) partition. This procedure evaluates the isolation observed near the partition. The appropriate measure is NR, and the appropriate single number rating is NIC.
It is sometimes necessary to demonstrate that the sound insulation of a partition meets or exceeds a specific criterion. Annex A1 provides additional requirements, and describes how shielding procedures can be used to reduce flanking transmission in stages to show that a partition has achieved a minimum value of the FTL or minimum value of the FSTC which may meet or exceed the criterion. If it is demonstrated that no significant flanking exists through shielding of all potential flanking paths, then, and only then, FTL and FSTC may be reported ...
SCOPE
1.1 The sound isolation between two spaces in a building is determined by a combination of the direct transmission through the nominally separating building element (as normally measured in a laboratory) and any transmission along a number of indirect paths, usually referred to as flanking paths. Fig. 1 illustrates the direct paths and some possible structural flanking paths. Additional non-structural flanking paths may include transmission through common air ducts between rooms, or doors to the corridor from adjacent rooms.
1.2 The main part of this test method defines procedures and metrics to assess the sound isolation between two rooms or portions thereof in a building separated by a common partition including both direct and flanking transmission paths or the apparent sound insulation of the separating partition. Appropriate measures and their single number ratings are the noise reduction (NR) and noise isolation class (NIC), the normalized noise reduction (NNR) and normalized noise isolation class (NNIC), and the apparent transmission loss (ATL) and apparent sound transmission class (ASTC). With the exception of the ATL and ASTC under specified conditions, these procedures in the main part of the test method are only applicable when both room volumes are less than 150 m3.
Note 1—The word “partition” in this test method includes all types of walls, floors, or any other boundaries separating two spaces. The boundaries may be permanent, operable, or movable.
1.3 Annex A1 provides methods to assess the sound transmission through a partition or partition element with the influence of flanking transmission reduced. These methods may be used when it must be demonstrated that a partition has achieved a specified minimum sound attenuation. The results are the field transmission loss (FTL) and field sound transmission class (FSTC).
1.4 Annex A2 provides methods to measure the sound isolation between portions of two ...

SIGNIFICANCE AND USE
The best uses of this guide are to measure the OINR and the AOITL(θ) or OITL(θ) at specific angles of incidence. By measuring the AOITL(θ) or OITL(θ) at several loudspeaker sound incidence angles, by energy-averaging the receiving room sound levels before computing results, an approximation of the diffuse field results measured with Test Methods E90 and E336 may be obtained.
The traffic noise method is to be used only for OINR measurements and is most suitable for situations where the OINR of a specimen at a specific location is exposed to an existing traffic noise source.
5.3 The OINR, AOITL(θ), and OITL(θ) produced by the methods described will not correspond to the transmission loss and noise reduction measured by Test Methods E90 and E336 because of the different incident sound fields that exist in the outdoors (1) . All of these results are a function of the angle of incidence of the sound for two reasons.
5.3.1 The transmission loss is strongly influenced by the coincidence effect where the frequency and projected wavelength of sound incident at angle, θ, coincides with the wavelength of a bending wave of the same frequency in the panel  (2, 3, 4, 5). This frequency and the angle of least transmission loss (greatest transparency) both depend on specimen panel stiffness, damping and area mass. In diffuse-field testing as in the laboratory, the effect is a weakness at the diffuse field average coincidence frequency that is dependent on material and thickness, often seen around the frequency of 2 500 Hz for drywall and glass specimens. For free field sound coming from one direction only, the coincidence frequency varies with incidence angle and will differ from the diffuse-field value  (5). Near or at grazing (θ =90º) it will be much lower in frequency than the diffuse field (E90 and E336) value, and will increase with reducing θ to be considerably above the diffuse-field frequency when θ is 30º or less. Wood panels (that is, doors) and masonry walls exhibi...
SCOPE
1.1 This guide may be used to determine the outdoor-indoor noise reduction (OINR), which is the difference in sound pressure level between the free-field level outdoors in the absence of the structure and the resulting sound pressure level in a room. Either a loudspeaker or existing traffic noise or aircraft noise can be used as the source. The outdoor sound field geometry must be described and calculations must account for the way the outdoor level is measured. These results are used with Classification E1332 to calculate the single number rating outdoor-indoor noise isolation class, OINIC. Both OINR and OINIC can vary with outdoor sound incidence angle.
1.2 Under controlled circumstances where a single façade is exposed to the outdoor sound, or a façade element such as a door or window has much lower transmission loss than the rest of the façade, an outdoor-indoor transmission loss, OITL(θ), or apparent outdoor-indoor transmission loss, AOITL(θ), may be measured using a loudspeaker source. These results are a function of the angle of incidence of the sound field. By measuring with sound incident at many angles, an approximation to the diffuse field transmission loss as measured between two rooms can be obtained. The results may be used to predict interior sound levels in installations similar to that tested when exposed to an outdoor sound field similar to that used during the measurement. The single number ratings of apparent outdoor-indoor transmission class, AOITC(θ), using AOITL(θ) and field outdoor-indoor transmission class, FOITC(θ), using OITL(θ) may be calculated using Classification E1332. These ratings also may be calculated with the data obtained from receiving room sound pressure measurements performed at several incidence angles as discussed in 8.6.
1.3 To cope with the variety of outdoor incident sound field geometries that are encountered in the field, six testing techniques are presented. These tech...

SIGNIFICANCE AND USE
The best uses of this guide are to measure the OINR and the AOITL(θ) or OITL(θ) at specific angles of incidence. By measuring the AOITL(θ) or OITL(θ) at several loudspeaker sound incidence angles, by energy-averaging the receiving room sound levels before computing results, an approximation of the diffuse field results measured with Test Methods E90 and E336 may be obtained.
The traffic noise method is to be used only for OINR measurements and is most suitable for situations where the OINR of a specimen at a specific location is exposed to an existing traffic noise source.
5.3 The OINR, AOITL(θ), and OITL(θ) produced by the methods described will not correspond to the transmission loss and noise reduction measured by Test Methods E90 and E336 because of the different incident sound fields that exist in the outdoors (1) . All of these results are a function of the angle of incidence of the sound for two reasons.
5.3.1 The transmission loss is strongly influenced by the coincidence effect where the frequency and projected wavelength of sound incident at angle, θ, coincides with the wavelength of a bending wave of the same frequency in the panel  (2, 3, 4, 5). This frequency and the angle of least transmission loss (greatest transparency) both depend on specimen panel stiffness, damping and area mass. In diffuse-field testing as in the laboratory, the effect is a weakness at the diffuse field average coincidence frequency that is dependent on material and thickness, often seen around the frequency of 2 500 Hz for drywall and glass specimens. For free field sound coming from one direction only, the coincidence frequency varies with incidence angle and will differ from the diffuse-field value  (5). Near or at grazing (θ =90º) it will be much lower in frequency than the diffuse field (E90 and E336) value, and will increase with reducing θ to be considerably above the diffuse-field frequency when θ is 30º or less. Wood panels (that is, doors) and masonry walls exhibi...
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1.1 This guide may be used to determine the outdoor-indoor noise reduction (OINR), which is the difference in sound pressure level between the free-field level outdoors in the absence of the structure and the resulting sound pressure level in a room. Either a loudspeaker or existing traffic noise or aircraft noise can be used as the source. The outdoor sound field geometry must be described and calculations must account for the way the outdoor level is measured. These results are used with Classification E1332 to calculate the single number rating outdoor-indoor noise isolation class, OINIC. Both OINR and OINIC can vary with outdoor sound incidence angle.
1.2 Under controlled circumstances where a single façade is exposed to the outdoor sound, or a façade element such as a door or window has much lower transmission loss than the rest of the façade, an outdoor-indoor transmission loss, OITL(θ), or apparent outdoor-indoor transmission loss, AOITL(θ), may be measured using a loudspeaker source. These results are a function of the angle of incidence of the sound field. By measuring with sound incident at many angles, an approximation to the diffuse field transmission loss as measured between two rooms can be obtained. The results may be used to predict interior sound levels in installations similar to that tested when exposed to an outdoor sound field similar to that used during the measurement. The single number ratings of apparent outdoor-indoor transmission class, AOITC(θ), using AOITL(θ) and field outdoor-indoor transmission class, FOITC(θ), using OITL(θ) may be calculated using Classification E1332. These ratings also may be calculated with the data obtained from receiving room sound pressure measurements performed at several incidence angles as discussed in 8.6.
1.3 To cope with the variety of outdoor incident sound field geometries that are encountered in the field, six testing techniques are presented. These tech...

SIGNIFICANCE AND USE
These single-number ratings correlate in a general way with subjective impressions of sound transmission for speech, radio, television, and similar sources of noise in offices and buildings. This classification method is not appropriate for sound sources with spectra significantly different from those sources listed above. Such sources include machinery, industrial processes, bowling allies, power transformers, musical instruments, many music systems, and transportation noises such as motor vehicles, aircraft and trains. For these sources, accurate assessment of sound transmission requires a detailed analysis in frequency bands. A single-number sound transmission rating for building façade elements is given in Classification E1332.
The single-number ratings obtained can be used to compare the potential sound insulation of partitions or floors tested in laboratory conditions (STC) or the actual sound isolation between different suites in buildings (NNIC, NIC). The rating for a partition built and tested in a building may be lower than that obtained for a partition tested in a laboratory because of flanking transmission or construction errors.
Note 1—A similar rating procedure, described in ISO 717, provides single figure sound insulation ratings with a frequency range that extends from 100 to 3150 Hz with no maximum deficiency specified at individual frequencies. For most partitions, the two ratings differ by only one or two points.
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1.1 This classification covers methods of calculating single-number acoustical ratings for laboratory and field measurements of sound attenuation obtained in one-third octave bands.
1.2 The name given to the single-number rating is assigned by the test method that invokes this classification.
1.3 Test methods that invoke this classification include:
1.3.1 Test Method E90—The single-number rating is called sound transmission class (STC).
1.3.2 Test Method E336—Single-number ratings are field sound transmission class (FSTC), noise isolation class (NIC), and normalized noise isolation class (NNIC).
1.3.3 Test Method E596—The single-number rating is called noise isolation class (NIC).
1.3.4 Test Method E1414—The single-number rating is called ceiling attenuation class (CAC).
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

SIGNIFICANCE AND USE
This classification provides a single number rating for transmission loss or noise reduction data that have been measured or calculated. This rating is based on the difference between the overall A-weighted sound level of the sound spectrum given in Table 1 and the overall A-weighted sound level of the spectrum that results from arithmetically subtracting the transmission loss or noise reduction data from this spectrum. The spectrum shape is an average of three typical spectra from transportation sources (aircraft takeoff, freeway, and railroad passby). A study showed that this classification correlated well with the A-weighted and loudness reductions (see ISO 532) calculated for each of the typical spectra for the one-third octave band range of 50 to 5000 Hz. The calculated numeric value of the rating is based on the sound transmission loss or noise reduction values for a particular specimen and depends only on that data and the shape of the reference source spectrum used in the calculation. The values shown in Table 1 have an arbitrary reference level. Single-number ratings should always be used with caution. Specimens having the same rating can result in different indoor spectra depending on the variation of their transmission loss with frequency. Also, if the actual spectrum of the outdoor sound is different from that assumed in Table 1, the overall A-weighted outdoor-indoor noise reduction may be different from the OINIC.
This classification requires sound transmission loss (TL), apparent outdoor-indoor transmission lost (AOITL(θ)) , or outdoor-indoor noise reduction measurements (OILR(θ)) in one-third octave bands from 80 to 4000 Hz. Due to accuracy limitations given in Test Method E90 and Guide E966, measurements below the 100 Hz one-third octave band are not usually reported. Studies have shown that data in the 80 Hz one-third octave band are necessary to obtain acceptable correlations for transportation sound sources. For the purposes of this classificati...
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1.1 The purpose of this classification is to provide a method to calculate single-number ratings that can be used for assesing the isolation for the outdoor sound provided by a building or comparing building facade specimens including walls, doors, windows, and combinations thereof, including complete structures. These ratings are designed to correlate with subjective impressions of the ability of building elements to reduce the penetration of outdoor ground and air transportation noise. These ratings provide an evaluation and rank ordering of the performance of test specimens based on their effectiveness at controlling the sound of a specific outdoor sound spectrum called the reference source spectrum.  
1.2 In addition to the calculation method, this classification defines some ratings not defined in other standards. Other standards may define additional ratings based on the method of this classification.
1.3 The rating does not necessarily relate to the perceived aesthetic quality of the transmitted sound. Different facade elements with similar ratings may differ significantly in the proportion of low and high frequency sound that they transmit. It is best to use specific sound transmission loss values, in conjunction with actual spectra of outdoor and indoor sound levels, for making final selections of facade elements.
1.4 Excluded from the scope of this classification are applications involving noise spectra differing markedly from those described in 4.1. Thus excluded, for example, would be certain industrial noises with high levels at frequencies below the 80 Hz one-third octave band, relative to levels at higher frequencies. However, for any source with a spectrum similar to those in 4.1, this classification provides a more reliable ranking of the performance of partitions and facade elements than do other classifications such as Classification E413.  
1.5 The values stated in SI units are to be regarded as...

SIGNIFICANCE AND USE
This guide can be used to produce a specification for the acoustical performance of an enclosure.
This guide is intended for those familiar with basic concepts of acoustics.
Although this guide provides detailed guidance in matters relating to specification of acoustical enclosures, it is not a substitute for the experience and judgment of an acoustical or noise control professional.
This guide calls for measurements common within acoustical practice.
The more critical the performance requirements of the enclosure, the more the user should consider seeking the services of an acoustics or noise control professional.
The specifying of a sound-isolating enclosure has three sequential steps:
Determine the sound pressure levels that exist at specific locations prior to the introduction of the enclosure,
Note 1—In the case of new construction, the sound pressure level is often estimated from the sound power levels of noise-emitting equipment and a general description of the acoustical properties of the environment.
Determine the maximum permissible sound pressure levels that must exist at the same locations after the introduction of the enclosure, and
Determine the required enclosure level reduction. The required isolation is related to the difference between the sound pressure levels before and after the introduction of the enclosure.
Many specifications are for multiple enclosures or enclosures with multiple functions, or both. It is beyond the scope of this guide to provide detailed guidance for every possible combination. Separate specifications for each source-enclosure-receiver combination should be used in such a case.
The type of specification that should be selected depends both on the purpose of the enclosure and how crucial its performance is. In general:
If exceeding a particular maximum permissible sound pressure level spectrum would render the enclosure unsuccessful, a sound pressure level specification should be used.
This guide a...
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1.1 The guide covers the development of criteria for the acoustical performance of a broad variety of acoustical enclosures by identifying information necessary to unambiguously describe acoustical performance. This guide is not a standard ASTM specification for a sound-isolating enclosure.
1.2 Excluded from the scope of this guide are technical considerations for enclosure design that do not pertain directly to acoustical performance.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.