EN 458:2025

SLOVENSKI STANDARD
oSIST prEN 458:2025
01-januar-2025
Varovala sluha - Priporočila za izbiro, uporabo, nego in vzdrževanje - Navodilo
Hearing protectors - Recommendations for selection, use, care and maintenance -
Guidance document
Gehörschützer - Empfehlungen für Auswahl, Einsatz, Pflege und Instandhaltung -
Leitfaden
Protecteurs individuels contre le bruit - Recommandations relatives à la sélection, à
l'utilisation, aux précautions d'emploi et à l'entretien - Document guide
Ta slovenski standard je istoveten z: prEN 458
ICS:
13.340.20 Varovalna oprema za glavo Head protective equipment
oSIST prEN 458:2025 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN 458:2025
oSIST prEN 458:2025
DRAFT
EUROPEAN STANDARD
prEN 458
NORME EUROPÉENNE
EUROPÄISCHE NORM
November 2024
ICS 13.340.20 Will supersede EN 458:2016
English Version
Hearing protectors - Recommendations for selection, use,
care and maintenance - Guidance document
Protecteurs individuels contre le bruit - Gehörschützer - Empfehlungen für Auswahl, Einsatz,
Recommandations relatives à la sélection, à Pflege und Instandhaltung - Leitfaden
l'utilisation, aux précautions d'emploi et à l'entretien -
Document guide
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 159.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations
which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 458:2024 E
worldwide for CEN national Members.

oSIST prEN 458:2025
prEN 458:2024(E)
Contents Page
European foreword . 4
Introduction . 5
5.1 Design forms . 9
5.2 Function mode . 10
6.1 Principles . 11
6.2 Selection according to sound attenuation . 12
6.3 Selection according to work environment . 16
6.4 Communication . 20
6.5 Compatibility with other Personal Protective Equipment (PPE) . 20
6.6 Selection according to hearing protector type and situation of use. 20
6.7 Medical factors . 21
6.8 Ergonomics and fitting . 22
7.1 General. 22
7.2 Availability of hearing protectors . 22
7.3 Correct fitting . 22
7.4 Simultaneous use of hearing protector with other PPE . 24
7.5 Speech intelligibility and signal audibility . 25
7.6 Instruction and training . 25
7.7 Period of use . 26
7.8 Leisure activities . 27
8.1 General. 27
8.2 Hygiene and cleaning . 27
8.3 Inspection and replacement . 27
8.4 Storage . 27
8.5 Disposal . 27
Annex A (normative) Methods for estimating the level effective to the ear when selecting a
hearing protector based on the national regulation level L' . 29
NR
A.1 General. 29
A.2 Octave band method . 32
A.3 HML method . 33
A.4 HML check method . 34
A.5 SNR method . 36
Annex B (informative) Method for estimating the level effective to the ear when selecting a
hearing protector based on the national peak regulation level L' . 38
NR, peak
B.1 General. 38
B.2 Method . 38
Annex C (informative) Selection method for sound-restoration level-dependent hearing
protectors intended for all types of noise environment using HML-criterion values . 40
C.1 General. 40
C.2 Method 1: HML Method . 40
C.3 Method 2A: HML check method – Measurement check . 41
C.4 Method 2B: HML check method – Listening method . 41
Annex D (informative) Calculation method for hearing protectors with audio input . 43
D.1 General. 43
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D.2 Method . 43
Annex E (informative) Improving field performance and special instructions for use . 45
E.1 Improving field performance . 45
E.2 Instructions for use . 46
Annex F (informative) Further guidance on individual fit testing methods . 49
F.1 General information . 49
F.2 Available individual fit testing methods . 49
Annex G (informative) Noise types . 51
Annex H (informative) Sustainability . 54
H.1 General . 54
H.2 Manufacturer evaluation (sourcing) . 54
H.3 Product attributes (sourcing and safety) . 55
H.4 Instruction and training (supervision) . 55
H.5 Cleaning, maintenance and disposal (correct use) . 56
H.6 Transportation, distribution and storage (safety and sourcing) . 56
Annex I (informative) Significant technical changes between this document and the
previous edition EN 458:2016 . 57
Bibliography . 59

oSIST prEN 458:2025
prEN 458:2024(E)
European foreword
This document (prEN 458:2024) has been prepared by Technical Committee CEN/TC 159 “Hearing
protectors”, the secretariat of which is held by DIN.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 458:2016.
The main changes compared to the previous edition are listed in Annex I.
oSIST prEN 458:2025
prEN 458:2024(E)
Introduction
This document is intended to guide employers, supervisors and safety advisors. Additionally, this
document gives information to all who need to use hearing protectors.
Hearing protectors are intended to protect against the risk of harmful noise and are elevated into the
highest risk Category III under the Personal Protective Equipment Regulation (EU) 2016/425, which
can cause irreversible health effects or can be potentially life threatening. They are intended to reduce
the harmful effects that sound and noise can have on the hearing of an individual worker. Requirements
for hearing protection products are given in the EN 352 series.
Guidance is provided on how to best select, use and maintain such devices. Calculation procedures to
estimate the residual noise exposure level, when a certain hearing protector is used, are also provided.
National bodies can develop their own local application documents based on this document.
Hearing protectors are generally available in two main forms: earmuffs and earplugs. Both forms are
available with additional features and functions. All have their advantages and disadvantages in terms
of attenuation, comfort, ease of use, communication facilities and cost.
In hearing conservation programmes noise hazard areas are identified and the personal noise exposure
is assessed. Before a suitable hearing protector is considered, priority should be given to reducing noise
at source and/or reducing the exposure time.
If the use of a hearing protector is found necessary or advisable, choosing optimum devices is a complex
task. The most important aspects for hearing protector performance include sufficient attenuation and
usage during the entire exposure period.
It is often desirable to retain the ability to hear speech and warning signals. If the hearing protector is a
passive device only, the hearing protector should not provide excessive attenuation (over-protection),
which can create a feeling of isolation and difficulties with perception of important sounds. In
particular, this needs attention at moderate noise levels.
Hearing protectors are supplied with attenuation data in various formats. The attenuation is expressed
in decibels and has been derived from laboratory tests. It is important to note that these data have been
achieved under controlled laboratory conditions using trained test subjects. Under real working
conditions, the attenuation achieved by the user can be lower than that generated by the laboratory
testing.
The performance of hearing protectors is subject to natural variability in the anatomy amongst users.
Correct fitting, training, regular inspection and user motivation are important to obtain the desired
protection. Due to the natural variability, it is not possible to calculate the exact attenuation that a
certain hearing protector will give for an individual. If a more accurate prediction is required, an
individual fit test is strongly recommended. At high noise level exposures it is advisable to seek expert
advice. In some cases dual protection i.e. the use of an earmuff and an earplug combination, can be
required.
For hearing protectors to be effective they should be used at all times when the user is in a potentially
hazardous noise environment. When selecting hearing protectors, attention should be given to factors
influencing comfort and user preference.
This document also provides advice on how to consider sustainability.
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prEN 458:2024(E)
1 Scope
This document gives recommendations for the selection, use, care and maintenance of hearing
protectors.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 352-6, Hearing protectors — Safety requirements — Part 6: Earmuffs with safety-related audio input
EN 352-8, Hearing protectors — Safety requirements — Part 8: Entertainment audio earmuffs
EN 352-9, Hearing protectors — Safety requirements — Part 9: Earplugs with safety-related audio input
EN 352-10, Hearing protectors — Safety requirements — Part 10: Entertainment audio earplugs
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp/
— IEC Electropedia: available at https://www.electropedia.org/
3.1
daily noise exposure level
L
EX,8h
A-weighted noise exposure level normalized to a nominal 8 h working day according to EN ISO 9612
3.2
peak sound pressure level
L
p,Cpeak
C-weighted instantaneous peak sound pressure level according to EN ISO 9612
3.3
national regulation level
L'
NR
daily noise exposure level (L ) effective to the ear according to national regulations
EX,8h
Note 1 to entry: National laws or regulations determine the levels of exposure at which hearing protectors shall be
provided or used.
3.4
national peak regulation level
L'
NR,peak
peak pressure level L effective to the ear according to national regulations
p,Cpeak
Note 1 to entry: National laws or regulations determine the levels of exposure at which hearing protectors shall be
provided or used.
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prEN 458:2024(E)
3.5
effective attenuation
measure of protection afforded by the hearing protector for the user
3.6
A-weighted sound pressure level
L
p,A
sound pressure level with frequency weighting A according to EN 61672-1
3.7
A-weighted sound pressure level effective to the ear
L'
p,A
A-weighted diffuse-field related equivalent sound pressure level under the hearing protector for the
external sound pressure level L
p,A
3.8
C-weighted sound pressure level
L
p,C
sound pressure level with frequency weighting C according to EN 61672-1
3.9
A-weighted equivalent sound pressure level effective to the ear
L'
p,A,eqT
A-weighted diffuse-field related equivalent sound pressure level under the hearing protector for the
external sound pressure level for time period T L
p,A,eqT
Note 1 to entry: For simplicity of notation, the subscript T is omitted throughout the following text.
3.10
effective daily noise exposure level
L'
EX,8h
A-weighted diffuse-field related equivalent sound pressure level under the hearing protector for the
external noise exposure level L
EX,8h
3.11
peak sound pressure level effective to the ear
L'
p,Cpeak
C-weighted peak sound pressure level under the hearing protector for the external sound pressure level
L
p,Cpeak
3.12
flat frequency response
attenuation which is constant (or nearly constant) over the frequency range between 125 Hz and
8 000 Hz (H – L ≤ 9 dB)
Note 1 to entry: See A.1 for explanation of “H” and “L”.
Note 2 to entry: Slope of the linear regression of mean attenuation values from 125 up to 4 000 fulfils the criterion
proposed by Liedtke [4] with a value lower than 3.6 dB, or very approximately H – L < 9 dB.
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prEN 458:2024(E)
3.13
fit testing
procedure for checking that a specific hearing protector is suitable for use by a
specific individual by assessing the physical fit, seal, sound attenuation or other properties of the
hearing protector
[SOURCE: EN 17479:2021, 3.1]
3.14
personal attenuation rating
PAR
individual attenuation given as a single value in dB that a user obtains for the fit of the hearing
protector that was tested
Note 1 to entry: The PAR can be either the combined left-right (binaural) or separate left-right ear value.
Note 2 to entry: The calculation procedure is not standardized and is specified by the manufacturer for a specific
fit testing method.
[SOURCE: EN 17479:2021, 3.4]
4 Symbols and abbreviations
For the purposes of this document, the following symbols and abbreviations apply.
f centre frequency of the octave band in Hz
L equivalent sound pressure level
p,eq
L sound pressure level for a single octave band
p,oct
L , equivalent sound pressure level for a single octave band
p,oct eq
PNR predicted noise level reduction according to EN ISO 4869-2
APV assumed protection value APV according to EN ISO 4869-2
f f84
H high-frequency attenuation value
M middle-frequency attenuation value
L low-frequency attenuation value
SNR Single Number Rating
rms root mean square
L daily noise exposure level
EX,8h
L C-weighted peak sound pressure level
p,Cpeak
L' national regulation level
NR
L' national peak regulation level
NR,peak
L A-weighted sound pressure level
p,A
L' A-weighted sound pressure level effective to the ear
p,A
L C-weighted sound pressure level
p,C
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L A-weighted equivalent sound pressure level
p,A,eqT
L C-weighted equivalent sound pressure level
p,C,eqT
L' A-weighted equivalent sound pressure level effective to the ear
p,A,eqT
NOTE For simplification of notation, the subscript T is omitted throughout the following text.
L' effective daily noise exposure level
EX,8h
L' peak sound pressure level effective to the ear
p,Cpeak
L maximum value of the sound pressure level with time-weighting F (fast) and frequency
C,Fmax
weighting C
L maximum value of the sound pressure level with time-weighting F (fast) and frequency
A,Fmax
weighting A
A frequency weighting A in dB for octave band centre frequency ƒ
f
L criterion level
crit
L maximum input signal level to the protector audio input
max
V Criterion voltage
crit
V maximum rms voltage input to the protector audio input
max
K constant for corresponding national regulation level
n maximum number of hours for use of audio input
PPE personal protective equipment
ANR active noise reduction
5 Types of hearing protectors
5.1 Design forms
5.1.1 Earmuffs
Earmuffs consist of cups which fit over the ears and are sealed to the head with soft cushions, usually
filled with foam and/or liquid. The cups are usually lined with sound absorptive material. They are
connected by a tensioning band (head band), usually made of metal and/or plastic. When the earmuff is
used behind-the-head or under-the-chin and has a mass in excess of 150 g, a flexible head strap is fitted
to each cup or to the head band close to the cups to support the earmuff. Some earmuffs have one cup
intended only for the left ear and the other only for the right ear. Earmuffs can be available in ‘medium
size range’, ‘small size range’ and ‘large size range’ types. ‘Medium size range' earmuffs will fit the
majority of users. ‘Small size range' or ‘large size range' earmuffs are designed to fit users for whom
‘medium size range' earmuffs are not suitable.
Earmuffs are available with head bands, neck bands, chin bands and universal bands. Earmuffs with
neck bands and chin bands permit the simultaneous using of a safety helmet. Universal bands can be
used over-the-head, behind-the-head or under-the-chin.
Requirements for earmuffs are specified in EN 352-1.
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5.1.2 Earmuffs attached to head protection and/or face protection devices
Earmuffs attached to head protection and/or face protection devices (also called mounted earmuffs)
consist of individual cups attached to arms that are mounted to a safety helmet or other equipment
serving as carrier for the hearing protector, such as rigid head top of a powered and supplied air
respirator system. The arms are adjustable so that the cups can be positioned over the ears.
Requirements for earmuffs attached to head protections and/or face protection devices are specified in
EN 352-3.
5.1.3 Earplugs
5.1.3.1 General
Earplugs are hearing protectors that are designed to be inserted into the ear canal or to cover the ear
canal entrance. They are sometimes provided with an interconnecting cord, rigid band or finger grips.
Earplugs can be either disposable (intended for single use) or reusable (intended for repeated use). All
types of earplugs except custom moulded earplugs can be available in range of sizes.
Requirements for earplugs are specified in EN 352-2.
5.1.3.2 Pre-shaped earplugs
Pre-shaped earplugs can readily be inserted into the ear canal without prior shaping. Pre-shaped
earplugs are available in a variety of materials.
5.1.3.3 User-formable earplugs
User-formable earplugs are made from compressible materials that the user forms before inserting
them into the ear canal. After insertion, these earplugs are designed to expand and form a seal within
the ear canal.
5.1.3.4 Banded earplugs
These are pre-shaped earplugs attached to a band which presses them into the ear canal or against the
entrance of the ear canal. Some are intended to be used in more than one position, e.g. with the band
under-the-chin.
5.1.3.5 Custom moulded earplugs
Custom moulded earplugs are individually moulded to fit the shape of the user’s ear canals typically
using an impression or a scan of the individual concha and the outer ear canal of the user. They can be
manufactured in a range of materials and with different acoustic filters to offer a range of attenuation.
5.2 Function mode
5.2.1 Basic function mode
All hearing protectors have the characteristics of reducing noise by their design and type of material
used, to absorb and/or reflect sound. Devices that have only this function are called passive devices.
They constitute the basis for all other additional function modes as described in 5.2.2 to 5.2.4.
5.2.2 Level-dependent hearing protectors
5.2.2.1 General
Level-dependent hearing protectors are designed to provide different attenuation as the external sound
level changes. Their main purpose is to protect against impulsive or intermittent hazardous noise while
allowing situational awareness.
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5.2.2.2 Passive level-dependent hearing protectors
Passive level-dependent hearing protectors use the acoustic properties of carefully designed air ducts
to give different protection at different noise levels. These types of hearing protectors are designed to
be effective against very high level single-impulse noises, such as firearms, rather than the continuous
noise or repetitive impulses found in most industrial situations.
5.2.2.3 Sound-restoration level-dependent hearing protectors
Sound-restoration level-dependent hearing protectors incorporate an electronic sound reproduction
system. At low sound pressure levels, the sound detected by an external microphone is amplified and
relayed to a loudspeaker inside the earmuff or earplug. As the external sound pressure level increases,
the electronics reduce the gain and control the level of reproduced sound inside the hearing protector.
Requirements for level-dependent hearing protectors are specified in EN 352-4 (for earmuffs) and
EN 352-7 (for earplugs), e.g. minimum criterion levels.
There are two types of sound-restoration level-dependent hearing protectors: products only intended
for use in impulsive type noise situations and products for all types of noise environment (continuous,
fluctuating and intermittent noise including impulsive noise, see Annex G).
5.2.3 Active noise reduction (ANR) protectors
These are hearing protectors which incorporate an electronic sound cancelling system to achieve
additional noise attenuation where passive hearing protectors can be less effective. ANR is particularly
effective at low frequencies (50 Hz to 500 Hz).
Requirements for active noise reduction earmuffs are specified in EN 352-5.
5.2.4 Hearing protectors with external audio input
5.2.4.1 General
These devices use a wired or wireless system through which communication signals, alarms, messages
or audio entertainment can be relayed. Some products incorporate a system to limit the sound pressure
level.
5.2.4.2 Hearing protector with entertainment audio input
These devices can incorporate a radio receiver set or music player for entertainment or allow audio
input from external devices. Such devices incorporate functions for limiting sound exposure.
Requirements for entertainment audio hearing protectors are specified in EN 352-8 (for earmuffs) and
EN 352-10 (for earplugs).
5.2.4.3 Hearing protector with safety-related audio input
These devices include wired or wireless input and/or built-in two-way radio and can be used for work-
related or safety-related communication. As the information to be received might be crucial for safety,
the product standards impose no limitation on the reproduced sound pressure level at the ear.
Requirements for hearing protectors with electrical audio input (for work or safety-related
communication) are specified in EN 352-6 (for earmuffs) and EN 352-9 (for earplugs).
6 Selection
6.1 Principles
Personal hearing protection should be selected so that, when used correctly and for the entire duration
of exposure, it will eliminate or minimize the risk to hearing.
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As there are many different hearing protectors intended for use in a wide range of noise environments
it is important to choose a suitable type. The product shall be checked for regulatory conformance.
Consideration should be given to the factors listed in a) to h). The list is neither exclusive nor
exhaustive:
a) sound attenuation, see 6.2;
b) work environment, see 6.3;
c) essential work or safety-related communication, especially speech intelligibility, see 6.4;
d) compatibility with other personal protective equipment (PPE), such as helmets, spectacles, etc., see
6.5;
e) the interaction between the user and the situation of use, see 6.6;
f) medical factors, see 6.7;
g) user comfort and ergonomic requirements, see 6.8;
h) sustainability aspects of the products, see Clause 9.
The selection procedure should be reviewed at regular intervals to ensure that an effective attenuation
is maintained. When considering all factors in the selection process the most important outcome is that
the hearing protector will be used during the whole time of noise exposure.
6.2 Selection according to sound attenuation
6.2.1 Guide to protection rating
Hearing protectors should be chosen according to the sound attenuation they will provide. Methods to
predict the sound attenuation of hearing protectors are given in 6.2.3.
NOTE 1 It is generally accepted that the risk of hearing damage associated with occupational noise exposure is
low where the daily noise exposure level (L ) is below 80 dB, and insignificant where L is below 75 dB.
EX,8h EX,8h
NOTE 2 National regulations or other guidelines can stipulate selection criteria for personal hearing protection
and place limits on sound exposure. Such relevant criteria and limits are often taken into account in deciding what
level of sound attenuation is required.
In general, a hearing protector which provides an effective sound level at the ear (L' ) of between
p,A,eq
70 dB and 80 dB is considered suitable. If the chosen hearing protector provides excessive attenuation,
users are at risk of failing to recognize warning signals and understand essential communications. Users
can also feel isolated from their working environment. The perception of isolation increases as the
sound level effective to the ear decreases.
Workers can be exposed to different noise environments during the working day. It can be possible to
select a single hearing protector which is adequate for all situations likely to be encountered, or in some
situations, to select more than one type of hearing protector.
EXAMPLE 1 A worker’s only significant noise exposure is to an L of 98 dB, for a total of 30 min per day.
p,A,eq
His L is 86 dB. His employer wishes to minimize the risk to the worker’s hearing, and so aims to provide a
EX,8h
hearing protector that provides an effective sound pressure level at the ear of below 80 dB, ideally between 75 dB
and 70 dB during the noise exposure. The employer selects a protector that provides a sound attenuation of
M = 26 dB.
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EXAMPLE 2 A worker spends the majority of her working day (a total of 6 h) in an environment with an L
p,A,eq
of 94 dB. Her L is around 93 dB. Her employer wishes to reduce the effective L' to at least below 80 dB,
EX,8h EX,8h
and to minimize the risk to the worker’s hearing. The employer rejects a protector that provides a sound
attenuation of M = 32 dB, as this would reduce the effective sound pressure level at the ear to 62 dB and so risk
excessive attenuation. The employer selects a protector that provides a sound attenuation of M = 22 dB.
6.2.2 Sound attenuation in practice
The attenuation afforded by a hearing protector when used under normal working conditions can differ
from that indicated on the device packaging or in the user information. This can be due to factors
including incorrect selection of type and/or size, use (see Clause 7), misuse and poor maintenance. For
remarks on improving field performance see Annex E.
These differences can be overcome by appropriate information, instruction and on-going training in the
use of the product. There are tools, referred to as “fit testing systems” that allow individual tests to be
carried out to verify the correct fit. Further information and guidance on these systems can be found in
7.3 and more extensively in EN 17479.
In the absence of fit testing, some countries have published specific guidance on de-rating the published
data in an attempt to address the issue of attenuation in practice. Refer to your national guidance for
further information.
NOTE Sound attenuation in practice can be referred to as real-world attenuation or field attenuation.
6.2.3 Acoustical selection methods
6.2.3.1 Overview of applicable methods
The applicability of methods for estimating the sound pressure level effective to the ear for different
types of hearing protector is summarized in Table 1. If the risk assessment indicates that the national
peak regulation level is likely to be exceeded, refer also to the last column of Table 1.
Table 1 — Applicability of acoustical selection methods to different types of hearing protector
Selection based only on Selection also based on
Type of hearing protector
L' L'
NR NR,peak
Passive Annex A Annex B
Passive level dependent Annex A Annex B
a
Sound restoration level dependent Annex C
Annex B
b a
ANR Annex A Annex B
a
Audio input Annex A and Annex D
Annex B
c c
Dual hearing protection
Annex A Annex B
a
using the passive attenuation data
b
using the total (passive and active) attenuation data
c
using the passive attenuation data for the combination
6.2.3.2 Methods for estimating the level effective to the ear when selecting a hearing protector
based on the national regulation level L'
NR
This approach is suitable for continuous, fluctuating and intermittent noise.
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When selecting a suitable hearing protector, consideration should be given to the characteristics of the
noise and the attenuation data of potentially suitable hearing protectors. The attenuation of most
hearing protectors varies with frequency. To determine if a hearing protector is (acoustically) suitable,
it is necessary to estimate the sound pressure level effective to the ear when the hearing protector is
used. There are four methods of estimating the sound pressure level effective to the ear. These are:
— Octave band method;
— HML method;
— HML check method;
— SNR method.
All four methods are explained in detail in Annex A including worked examples. Table 2 shows the type
of information on workplace noise needed for each estimation method.
Table 2 — Information on workplace noise required for assessing sound attenuation
Estimation method Information required
Octave band method (see A.2) octave band sound pressure level; L / L
p,oct p,oct,eq
HML method (see A.3) A and C-weighted sound pressure level; L and L / L and
p,A p,C p,A,eq
L
p,C,eq
A-weighted sound pressure level, L / L
p,A p,A,eq
HML check method (see A.4)
subjective decision between two noise classes (using lists of
examples of noise sources, see A.4)
SNR method (see A.5) C-weighted sound pressure level, L / L
p,C p,C,eq
For changing noise environments and/or exposure times it can be appropriate to use more than one
type of hearing protector in a working day. If the noise is not continuous but fluctuating or impulsive,
the equivalent level should be calculated or measured. The four estimation methods do not take account
of any de-rating values. Refer to your national guidance for further information on this issue (see 6.2.2).
6.2.3.3 Method for estimating the level effective to the ear when selecting a hearing protector
based on the national peak regulation level L'
NR, peak
The method described in Annex B is applicable to all hearing protectors. At high peak sound pressure
levels non-passive devices operate in the passive mode and therefore passive HML attenuation data are
used.
6.2.3.4 Selection method for sound-restoration level-dependent hearing protectors intended for
all types of noise environment, using HML criterion values
Annex C describes a method to aid the correct selection of a non-passive sound-restoration level-
dependent hearing protector for use in all types of noise environment. The method is applicable to both
earmuffs and earplugs using HML criterion level data obtained in accordance with EN 352-4 and
EN 352-7 respectively. The method can be suitable for other similar non-passive devices. The criterion
levels describe the maximum external noise level for which this product does not lead to more than
85 dB(A) effective to the ear. The criterion levels are determined with volume control set to maximum.
The annex determines only whether the hearing protector will reduce the A-weighted sound pressure
level effective to the ear to below the defined limit of 85 dB(A). This annex cannot give the specific level
at the ear.
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prEN 458:2024(E)
6.2.3.5 Method for estimating the level effective to the ear when an active noise reduction
hearing protector based on the national regulation level L'
NR
The selection can be made following the methods of Annex A according to the octave band method in
A.2, the HML method in A.3 or the HML check method in A.4, using the total attenuation values
according to EN 352-5. In addition, it should be checked that the external sound pressure level for
which the sound pressure level effective to the ear remains linear is not exceeded (these data are
obtained from the instructions for use). The outcome of the assessment is be compared to the national
regulation level L' . The product should be assessed based on the passive attenuation values in the
NR
event that the active noise reduction is not operational.
6.2.3.6 Method for estimating the level effective to the ear for a hearing protector with audio
input
When there is a need or demand for radio for essential communication or entertainment, hearing
protectors with an audio input are available. These are divided in two types: for entertainment
(listening to a music source) or for safety or work-related speech communication.
The user will be exposed to both the attenuated ambient noise and the audio input signal. Hearing
protectors with entertainment audio input shall conform to EN 352-8 (for earmuffs) or EN 352-10 (for
earplugs). For products with wireless or wired entertainment audio input the sound pressure level is
limited to 82 dB (L' ).
p,A,eq
For hearing protectors with electrical audio input the sound pressure level can exceed 82 dB(A) for
input voltages higher than those specified by the manufacturer. To minimize the risk of hazardous
exposure it is therefore recommended to select products with built-in limiter functions.
Where communication is essential, hearing protectors shall conform to EN 352-6 (for earmuffs) or
EN 352-9 (for earplugs). The following information is provided by the manufacturer:
— the input signal level corresponding to 82 dB(A) effective to the ear (criterion input signal);
— the relationship between sound output level and input signal in 5 dB steps from a sound output
level of 70 dB(A) up to the maximum input signal;
— the sound output level for maximum input signal;
— the usage time for the maximum input signal that corresponds to an equivalent sound output level
of 82 dB(A) over 8 h.
NOTE The usage time can be increased, if the input signal level is lowered.
If the contribution of the audio input signal to the sound level effective to the ear is substantial the
combined exposure should be considered. It can be necessary to reduce the contribution of the external
source. Annex D describes a calculation method for combining these sources.
When selecting this type of product, it is important to realize that the additional sound input will
negatively affect the awareness of the sound from the environment and warning signals. Systems
providing the input signal to only one ear might be a safer solution. The audibility of warning signals
shall be checked.
6.2.4 Selection of combination of earmuffs and earplugs
Personnel working in extremely noisy environments can require higher attenuation than a single
hearing protector can provide. In such cases, increased protection can be obtained by using a
combination of earmuffs and earplugs. Dual protection should be considered when the daily noise
exposure exceeds 105 dB(A) if there is substantial noise at frequencies below 500 Hz. For higher
oSIST prEN 458:2025
prEN 458:2024(E)
frequency dominant noise dual protection should be considered from 110 dB(A). The attenuation of a
combination of earmuffs and earplugs is not the sum of the attenuation of the individual protectors. The
typical increase in attenuation will depend on the noise, fit and what combination of protectors is used.
NOTE Results from 46 combination measurements show a range of 1 dB to 12 dB increase above the higher
SNR. For seven combinations of earmuffs with high attenuating earplugs an increase in M-value between 5 dB and
9 dB was observed. The L-value can vary in a wider range and is dependent strongly on the attenuation of the
earplug.
Where dual protection is required, it is important to obtain attenuation data for the chosen combination
of earplug and earmuff (and helmet, if used), e.g. by contacting the manufacturer. If both the earplug
and earmuff are well fitted, the increase in attenuation is mainly at frequencies below 1 000 Hz. Bone
conduction can limit the total sound attenuation, particularly around 2 000 Hz. The most suitable
combinations of earplug and earmuff (dual hearing protection) are dependent on both the noise as well
as any need for communication, situational awareness and issues related to use of personal protect
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