EN 17479:2021

SLOVENSKI STANDARD
01-januar-2022
Varovala sluha - Navodila za izbiro ustreznih preskusnih metod za individualno
prilagajanje
Hearing protectors - Guidance on selection of individual fit testing methods
Gehörschützer - Leitfaden zur Auswahl von Prüfverfahren für die individuelle Passung
Protecteurs individuels contre le bruit - Recommandations relatives au choix des
méthodes individuelles de contrôle de l'ajustement
Ta slovenski standard je istoveten z: EN 17479:2021
ICS:
13.340.20 Varovalna oprema za glavo Head protective equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 17479
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2021
EUROPÄISCHE NORM
ICS 13.340.20
English Version
Hearing protectors - Guidance on selection of individual fit
testing methods
Protecteurs individuels contre le bruit - Gehörschützer - Leitfaden zur Auswahl von
Recommandations relatives au choix des méthodes Prüfverfahren für den individuellen Sitz
individuelles de contrôle de l'ajustement
This European Standard was approved by CEN on 13 September 2021.

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. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists 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, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 17479:2021 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Individual fit testing methods . 7
4.1 General . 7
4.2 Test methods . 8
4.3 Reference method for sound attenuation measurements of hearing protectors . 9
4.4 Description of different fit testing methods . 9
5 Test procedure of the fit testing methods . 16
5.1 General . 16
5.2 Sound-level measurements with microphone in real ear (MIRE) (method 1) . 16
5.3 Audiometric method (method 2) . 18
5.4 Audiometric-based method (method 3) . 21
5.5 Loudness balancing (method 4) . 22
5.6 Acoustic leakage test (method 5) . 23
5.7 Air leakage test (method 6) . 24
6 Evaluation criteria . 25
6.1 Application field of the different methods . 25
6.2 Selection according to ease of use . 27
6.3 Individual care for workers with hearing impairment . 28
6.4 Applicability of methods to the different types of hearing protectors . 29
7 Frequency of fit testing . 30
8 Uncertainty . 30
8.1 General factors for the uncertainty of fit testing . 30
8.2 Particular factors regarding the uncertainty for the different fit testing methods . 31
8.3 Quantitative approach. 33
9 Test report . 34
Annex A (informative) Comparison to target values . 36
Annex B (informative) Example of a protocol for the determination of measurement
uncertainty . 40
Bibliography . 41

European foreword
This document (EN 17479:2021) has been prepared by Technical Committee CEN/TC 159 “Hearing
protectors”, the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by May 2022, and conflicting national standards shall be
withdrawn at the latest by May 2022.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: 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, Turkey and the United
Kingdom.
Introduction
The need for the use of hearing protectors is obvious nowadays. Appropriate hearing protection is chosen
based on different selection criteria such as required sound attenuation, comfort, workplace environment
and a possible need for communication, audibility of important sounds etc. Different selection criteria for
hearing protector selection are given in EN 458:2016 “Hearing protectors — Recommendations for
selection, use, care and maintenance — Guidance document” [4].
As appropriate sound attenuation should be key in this selection process, this should be compared to the
user’s need in two steps. Firstly, appropriate hearing protection should be selected based on the
attenuation data from the REAT test according to EN ISO 4869-1:2018 [7] and EN ISO 4869-2:2018 [8],
as provided by the manufacturer. Secondly, by using individual fit testing methods the effective
attenuation can be assessed (e.g. acoustic or pressure sealing, personal attenuation rating, etc.).
In addition, the effective attenuation can be estimated and compared to the required sound attenuation.
Whilst fit testing can play a valuable role in the selection and usage, it is no substitute for conformity
testing.
Fit testing can also be used to increase the awareness of the user on the importance of a proper fit. It can
help the user achieve a fit that maximizes the likelihood of that user receiving the expected level of
protection. It could also form part of the training for safety engineers, healthcare specialists and
supervisors, to provide a good understanding of the importance of a proper fitting and it can also be a
helpful training aid for the user.
This document gives practical guidance for the appropriate selection of fit testing methods, their uses and
limitations.
This document does not specify the technical requirements for manufacturing fit testing equipment.
1 Scope
This document gives guidelines for the appropriate selection of fit testing methods and measurement,
and provides practical guidelines on fit testing methods, their uses and limitations.
This document does not specify the technical requirements for manufacturing fit testing equipment.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological 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
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
3.2
repeatability
closeness of the agreement between the results of successive measurements of the same test item carried
out under the same conditions of measurement
Note 1 to entry: These conditions are called repeatability conditions.
Note 2 to entry: Repeatability conditions include:
— the same measurement procedure;
— the same observer;
— the same measuring instrument, used under the same conditions;
— the same location;
— repetition over a short period of time.
Note 3 to entry: Repeatability may be expressed quantitatively in terms of the dispersion characteristics of the
results.
[SOURCE: ISO/IEC Guide 98-3:2008, B.2.15, modified: “(of results of measurements)” deleted in term
designation and “measurand” replaced by “test item”.]
3.3
reproducibility
closeness of the agreement between the results of measurements of the same test item carried out under
changed conditions of measurement
Note 1 to entry: A valid statement of reproducibility requires specification of the conditions changed.
Note 2 to entry: The changed conditions may include:
— principle of measurement;
— method of measurement;
— observer;
— measuring instrument;
— reference standard;
— location;
— provision of suitable facility (e.g. sound booth);
— conditions of use;
— time.
Note 3 to entry: Reproducibility may be expressed quantitatively in terms of the dispersion characteristics of the
results.
Note 4 to entry: Results are here usually understood to be corrected results.
[SOURCE: ISO/IEC Guide 98-3:2008, B.2.16, modified: “(of results of measurements)” deleted in term
designation and “measurand” replaced by “test item”.]
3.4
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.
3.5
real-ear attenuation at threshold method
REAT method
test procedure for determination of the sound attenuation of a hearing protector
Note 1 to entry: The measurement of sound attenuation is described in EN ISO 4869-1 [7].
3.6
threshold of hearing
lowest sound pressure level at which, under specified conditions, a person gives a predetermined
percentage of correct detection responses on repeated trials
Note 1 to entry: For the purpose of this document, the threshold of hearing is measured w
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