Electroacoustics - Hearing aids - Part 13: Requirements and methods of measurement for electromagnetic immunity to mobile digital wireless devices

IEC 60118-13:2019 covers the relevant EMC phenomena for hearing aids. Hearing aid immunity to high frequency fields originating from digital wireless devices such as mobile phones was identified as one of the most relevant EMC phenomena impacting hearing aids.
IEC 60118-13:2019 cancels and replaces the fourth edition published in 2016 and constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) it introduces a new measurement method and set of EMC requirements for hearing aids immunity to mobile digital wireless devices;
b) generic EMC requirements for hearing aids are no longer included – should be covered by other standards as appropriate.

Electroacoustique - Appareils de correction auditive - Partie 13: Exigences et méthodes de mesure de l'immunité électromagnétique aux appareils numériques mobiles sans fil

L'IEC 60118-13:2019 s'applique aux phénomènes de compatibilité électromagnétique (CEM) concernant les appareils de correction auditive. L'immunité des appareils de correction auditive aux champs de haute fréquence produits par les appareils numériques sans fil tels que les téléphones mobiles a été identifiée comme l'un des phénomènes de CEM les plus pertinents ayant un impact sur les appareils de correction auditive.
L'IEC 60118-13:2019 annule et remplace la quatrième édition parue en 2016, dont elle constitue une révision technique.
Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a) elle introduit une nouvelle méthode de mesure et un ensemble d'exigences de CEM relatives à l'immunité des appareils de correction auditive aux appareils numériques mobiles sans fil;
b) les exigences générales CEM pour les appareils de correction auditive ne sont plus incluses (il convient qu'elles soient couvertes par d'autres normes, selon le cas.

General Information

Status
Published
Publication Date
28-Oct-2019
Technical Committee
Current Stage
PPUB - Publication issued
Completion Date
29-Oct-2019
Ref Project

Buy Standard

Standard
IEC 60118-13:2019 - Electroacoustics - Hearing aids - Part 13: Requirements and methods of measurement for electromagnetic immunity to mobile digital wireless devices
English and French language
44 pages
sale 15% off
Preview
sale 15% off
Preview

Standards Content (sample)

IEC 60118-13
Edition 5.0 2019-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Electroacoustics – Hearing aids –
Part 13: Requirements and methods of measurement for electromagnetic
immunity to mobile digital wireless devices
Électroacoustique – Appareils de correction auditive–
Partie 13: Exigences et méthodes de mesure de l'immunité électromagnétique
aux appareils numériques mobiles sans fil
IEC 60118-13:2019-10(en-fr)
---------------------- Page: 1 ----------------------
THIS PUBLICATION IS COPYRIGHT PROTECTED
Copyright © 2019 IEC, Geneva, Switzerland

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form

or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from

either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC

copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or

your local IEC member National Committee for further information.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite

ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie

et les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des

questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez

les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.

IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC

The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes

International Standards for all electrical, electronic and related technologies.
About IEC publications

The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the

latest edition, a corrigendum or an amendment might have been published.

IEC publications search - webstore.iec.ch/advsearchform Electropedia - www.electropedia.org

The advanced search enables to find IEC publications by a The world's leading online dictionary on electrotechnology,

variety of criteria (reference number, text, technical containing more than 22 000 terminological entries in English

committee,…). It also gives information on projects, replaced and French, with equivalent terms in 16 additional languages.

and withdrawn publications. Also known as the International Electrotechnical Vocabulary

(IEV) online.
IEC Just Published - webstore.iec.ch/justpublished

Stay up to date on all new IEC publications. Just Published IEC Glossary - std.iec.ch/glossary

details all new publications released. Available online and 67 000 electrotechnical terminology entries in English and

once a month by email. French extracted from the Terms and Definitions clause of

IEC publications issued since 2002. Some entries have been

IEC Customer Service Centre - webstore.iec.ch/csc collected from earlier publications of IEC TC 37, 77, 86 and

If you wish to give us your feedback on this publication or CISPR.
need further assistance, please contact the Customer Service
Centre: sales@iec.ch.
A propos de l'IEC

La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des

Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications IEC

Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la

plus récente, un corrigendum ou amendement peut avoir été publié.
Recherche de publications IEC - Electropedia - www.electropedia.org

webstore.iec.ch/advsearchform Le premier dictionnaire d'électrotechnologie en ligne au

La recherche avancée permet de trouver des publications IEC monde, avec plus de 22 000 articles terminologiques en

en utilisant différents critères (numéro de référence, texte, anglais et en français, ainsi que les termes équivalents dans

comité d’études,…). Elle donne aussi des informations sur les 16 langues additionnelles. Egalement appelé Vocabulaire

projets et les publications remplacées ou retirées. Electrotechnique International (IEV) en ligne.

IEC Just Published - webstore.iec.ch/justpublished Glossaire IEC - std.iec.ch/glossary

Restez informé sur les nouvelles publications IEC. Just 67 000 entrées terminologiques électrotechniques, en anglais

Published détaille les nouvelles publications parues. et en français, extraites des articles Termes et Définitions des

Disponible en ligne et une fois par mois par email. publications IEC parues depuis 2002. Plus certaines entrées

antérieures extraites des publications des CE 37, 77, 86 et
Service Clients - webstore.iec.ch/csc CISPR de l'IEC.
Si vous désirez nous donner des commentaires sur cette
publication ou si vous avez des questions contactez-nous:
sales@iec.ch.
---------------------- Page: 2 ----------------------
IEC 60118-13
Edition 5.0 2019-10
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Electroacoustics – Hearing aids –
Part 13: Requirements and methods of measurement for electromagnetic
immunity to mobile digital wireless devices
Électroacoustique – Appareils de correction auditive–
Partie 13: Exigences et méthodes de mesure de l'immunité électromagnétique
aux appareils numériques mobiles sans fil
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 17.140.50; 33.100.20 ISBN 978-2-8322-7330-2

Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale
---------------------- Page: 3 ----------------------
– 2 – IEC 60118-13:2019 © IEC 2019
CONTENTS

FOREWORD ........................................................................................................................... 3

INTRODUCTION ..................................................................................................................... 5

1 Scope .............................................................................................................................. 6

2 Normative references ...................................................................................................... 6

3 Terms and definitions ...................................................................................................... 6

4 Operation and function of the hearing aid ........................................................................ 8

5 Requirements for electromagnetic immunity..................................................................... 8

5.1 General ................................................................................................................... 8

5.2 Compliance criteria ................................................................................................. 9

6 Test procedures for immunity to radiated RF electromagnetic fields .............................. 11

6.1 General ................................................................................................................. 11

6.2 Test setup ............................................................................................................. 11

6.3 Hearing aid test setting ......................................................................................... 11

6.4 Determination of gain ............................................................................................ 12

6.5 Measurement of the input related ambient noise (IRAN) ........................................ 12

6.6 Hearing aid output coupling during immunity test .................................................. 13

6.7 Position of the hearing aid during immunity test .................................................... 13

6.8 Measurement of the output related interference level (ORIL) ................................. 14

6.9 Calculation of the input related interference level (IRIL) ........................................ 15

6.10 Report................................................................................................................... 15

7 Measurement uncertainty for immunity to radiated RF electromagnetic fields ................ 16

Annex A (informative) Background for establishing test methods, performance criteria

and test levels ...................................................................................................................... 17

A.1 General ................................................................................................................. 17

A.2 Radiated RF electromagnetic fields – History of the test method ........................... 17

A.3 Performance criteria ............................................................................................. 19

A.4 Test field strengths – Bystander compatibility ....................................................... 19

A.5 Test field strengths – User compatibility ................................................................ 20

Bibliography .......................................................................................................................... 21

Figure 1 – Example of a test arrangement for hearing aid immunity measurements

using a GTEM cell ................................................................................................................ 11

Figure 2 – Examples of input-output response curves at 1 kHz and the determination

of gain at an input SPL of 55 dB ........................................................................................... 12

Figure 3 – Hearing aid test positions for BTE (upper) and ITE (lower) ................................... 14

Figure A.1 – Ratio of 1:2 between field strength and interference level in dB ........................ 18

Figure A.2 – Example of test arrangement for hearing aid immunity measurements

using dipole antenna ............................................................................................................. 20

Table 1 – Field strengths of RF test signals to be used to establish immunity for

bystander compatible and user compatible hearing aids ....................................................... 10

---------------------- Page: 4 ----------------------
IEC 60118-13:2019 © IEC 2019 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTROACOUSTICS –
HEARING AIDS –
Part 13: Requirements and methods of measurement
for electromagnetic immunity to mobile digital wireless devices
FOREWORD

1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising

all national electrotechnical committees (IEC National Committees). The object of IEC is to promote

international co-operation on all questions concerning standardization in the electrical and electronic fields. To

this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,

Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as "IEC

Publication(s)"). Their preparation is entrusted to technical committees; any IEC National Committee interested

in the subject dealt with may participate in this preparatory work. International, governmental and non-

governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely

with the International Organization for Standardization (ISO) in accordance with conditions determined by

agreement between the two organizations.

2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international

consensus of opinion on the relevant subjects since each technical committee has representation from all

interested IEC National Committees.

3) IEC Publications have the form of recommendations for international use and are accepted by IEC National

Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC

Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any

misinterpretation by any end user.

4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications

transparently to the maximum extent possible in their national and regional publications. Any divergence

between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in

the latter.

5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity

assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any

services carried out by independent certification bodies.

6) All users should ensure that they have the latest edition of this publication.

7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and

members of its technical committees and IEC National Committees for any personal injury, property damage or

other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and

expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC

Publications.

8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is

indispensable for the correct application of this publication.

9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of

patent rights. IEC shall not be held responsible for identifying any or all such patent rights.

International Standard IEC 60118-13 has been prepared by IEC technical committee 29:

Electroacoustics.

This fifth edition cancels and replaces the fourth edition published in 2016 and constitutes a

technical revision.

This edition includes the following significant technical changes with respect to the previous

edition:

a) it introduces a new measurement method and set of EMC requirements for hearing aids

immunity to mobile digital wireless devices;

b) generic EMC requirements for hearing aids are no longer included – should be covered by

other standards as appropriate.
---------------------- Page: 5 ----------------------
– 4 – IEC 60118-13:2019 © IEC 2019
The text of this International Standard is based on the following documents:
FDIS Report on voting
29/1024/FDIS 29/1031/RVD

Full information on the voting for the approval of this International Standard can be found in

the report on voting indicated in the above table.

This document has been drafted in accordance with the ISO/IEC Directives, Part 2.

A list of all parts in the IEC 60118 series, published under the general title Electroacoustics –

Hearing aids, can be found on the IEC website.

The committee has decided that the contents of this document will remain unchanged until the

stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to

the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates

that it contains colours which are considered to be useful for the correct

understanding of its contents. Users should therefore print this document using a

colour printer.
---------------------- Page: 6 ----------------------
IEC 60118-13:2019 © IEC 2019 – 5 –
INTRODUCTION

This part of IEC 60118 specifies methods of measurement and requirements for hearing aid

immunity to digital wireless devices. Most hearing aids contain digital signal processors and

some can contain wireless transceivers.

Experience in connection with the use of hearing aids in recent times has identified digital

wireless devices, such as wireless telephones and GSM mobile phones, as potential sources

of disturbance for hearing aids. Interference in hearing aids depends on the emitted power

from the digital wireless device as well as the immunity of the hearing aid. The performance

criteria in this document will not totally ensure hearing aid users' interference- and noise-free

use of wireless telephones, but will establish useable conditions in most situations.

In practice, a hearing aid user, when using a wireless telephone, will seek, if possible, to find

a position on the ear, which gives minimum or no interference in the hearing aid. Various test

methods have been considered for determining the immunity of hearing aids. When a digital

wireless device is used close to a hearing aid, there is an RF near-field illumination of the

hearing aid. However, validation investigations in preparing this document have shown that it

is possible to establish a correlation between the measured far-field immunity level and the

immunity level experienced by an actual hearing aid used in conjunction with a digital wireless

device. The use of a far-field test has shown high reproducibility and is considered sufficient

to verify and express the immunity of hearing aids. Near-field illumination of the hearing aid

(i.e. by generating an RF field using a dipole antenna) could however provide valuable

information during the design and development of hearing aids.

It is recognized that the new wireless products introduced have to coexist with existing

spectra, potential networks and other wireless products (medical as well as non-medical).

This revision does not address the issue of coexistence, and the user of this document shall

consult applicable entities for guidance.

In this fifth edition of IEC 60118-13, the field strengths and hearing aid positioning during

measurements have been updated for consistency with IEEE C63.19 [1] and

ANSI C63.19 [2]. The field strength levels used since the first edition of IEC 60118-13 was

published in 1997 have demonstrated, through measurements of more than 1 000 hearing aid

models (ref. European Hearing Instrument Manufacturers Association – EHIMA), to be

sufficiently high to ensure well-functioning hearing aids in everyday use, with only a small

expectation of a few complaints regarding interference from digital wireless devices.

Hearing aids where the outputs are non-acoustic, for example bone conduction hearing aids,

are not directly included in this document, but this document can be used if precise

descriptions of measurement setups for these types of hearing aids are given by the

manufacturer.
___________
Numbers in square brackets refer to the Bibliography
---------------------- Page: 7 ----------------------
– 6 – IEC 60118-13:2019 © IEC 2019
ELECTROACOUSTICS –
HEARING AIDS –
Part 13: Requirements and methods of measurement
for electromagnetic immunity to mobile digital wireless devices
1 Scope

This part of IEC 60118 covers the relevant EMC phenomena for hearing aids. Hearing aid

immunity to high frequency fields originating from digital wireless devices such as mobile

phones was identified as one of the most relevant EMC phenomena impacting hearing aids.

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.
IEC 60118-0:2015, Electroacoustics – Hearing aids – Part 0: Measurement of the
performance characteristics of hearing aids

IEC 60318-5, Electroacoustics – Simulators of human head and ear – Part 5: 2 cm coupler

for the measurement of hearing aids and earphones coupled to the ear by means of ear

inserts

IEC 61000-4-3, Electromagnetic compatibility (EMC) – Part 4-3: Testing and measurement

techniques – Radiated, radio-frequency, electromagnetic field immunity test

IEC 61000-4-20, Electromagnetic compatibility (EMC) – Part 4-20: Testing and measurement

techniques – Emission and immunity testing in transverse electromagnetic (TEM) waveguides

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:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
hearing aid

wearable instrument intended to aid a person with impaired hearing, usually consisting of a

microphone, amplifier, signal processor and earphone, powered by a low-voltage battery, and

possibly also containing an induction pick-up coil and which is fitted using audiometric and

prescriptive methods

Note 1 to entry: Hearing aids can be placed on the body (BW), behind the ear (BTE), in the ear (ITE) or in the

canal (ITC).
---------------------- Page: 8 ----------------------
IEC 60118-13:2019 © IEC 2019 – 7 –
3.2
bystander compatibility

immunity of a hearing aid that ensures it is usable in environments where digital wireless

devices are in operation in the proximity of the hearing aid wearer
3.3
user compatibility

immunity of a hearing aid that ensures that it is usable when the wearer is using a digital

wireless device at the wearer's own aided ear
3.4
gain

difference between the acoustic or the magnetic equivalent input level (L ) and the

p,in
respective acoustic output level (L )
p,out

Note 1 to entry: The gain is determined at an acoustic input sound pressure level (SPL) of 55 dB or (for induction

pick-up coils) at a magnetic field strength level re 1 A/m of −35 dB which is the magnetic equivalent of 55 dB

(SPL).
Note 2 to entry: G = L – L .
p,out p,in

Note 3 to entry: If not stated otherwise in this document, gain is determined at a frequency of 1 kHz.

3.5
output related interference level
ORIL

sound pressure level at the output of the hearing aid during exposure to a 1 kHz 80 %

amplitude modulated RF signal with time weighting FAST
Note 1 to entry: ORIL = L at 1 kHz, 80 % AM RF.
p, out
Note 2 to entry: This note applies to the French language only.
3.6
input related interference level
IRIL
ORIL with gain (G) subtracted:
IRIL = ORIL − G
Note 1 to entry: IRIL is used to characterize the immunity of a hearing aid.
Note 2 to entry: This note applies to the French language only.
3.7
input related ambient noise
IRAN

equivalent acoustic input sound pressure level that would lead to the acoustic noise output

produced by a hearing aid:
IRAN = ORIL − G
RF off
and
ORIL = L , RF switched off
RF off p, out

Note 1 to entry: IRAN is determined in the same way as IRIL but with the RF signal switched off.

Note 2 to entry: This note applies to the French language only.
---------------------- Page: 9 ----------------------
– 8 – IEC 60118-13:2019 © IEC 2019
3.8
GSM
global system for mobile communication
Note 1 to entry: This note applies to the French language only.
3.9
TEM cell

closed measuring device in which a voltage difference creates a TEM-mode electromagnetic

field
3.10
GTEM cell
TEM cell that has been altered to extend the usable frequency range
3.11
radio frequency
frequency of electromagnetic radiation within the range of 30 kHz to 30 GHz
Note 1 to entry: This note applies to the French language only.
3.12
microphone mode
hearing aid omnidirectional setting active
3.13
induction pick-up coil mode
hearing aid induction pick-up coil active
3.14
directional mode
hearing aid directional setting active
4 Operation and function of the hearing aid

Hearing aids basically consist of a microphone, an amplifier, an optional induction pick-up coil

and a small earphone (receiver). For behind the ear (BTE) hearing aids, the sound is often fed

to the ear canal by means of an individually made ear mould (ear insert), or with the receiver

in the auditory canal (RITE). In the ear (ITE) and in the canal (ITC) hearing aids, have the

active circuitry located in the ear.

The power source normally used is a small battery. On some hearing aids, the user can

perform some adjustments of the controls of the hearing aid.
5 Requirements for electromagnetic immunity
5.1 General

Clause 5 specifies the electromagnetic immunity requirements for hearing aids to wireless

digital devices. IEC 61000-4-3 describes testing and measurement techniques for general

radiated immunity which shall be applied. For the purpose of the radiated RF electromagnetic

field immunity requirements, two hearing aid user compatibility classes are defined (see 3.2

and 3.3) which are related to the hearing aid user's situation.

A "bystander compatible" hearing aid will ensure that the hearing aid is usable in

environments where digital wireless devices are in operation in the proximity of the hearing

aid wearer.
---------------------- Page: 10 ----------------------
IEC 60118-13:2019 © IEC 2019 – 9 –

A "user compatible" hearing aid will ensure that the hearing aid is usable when the hearing

aid wearer is using a mobile digital wireless device at the wearer's own aided ear.

5.2 Compliance criteria

To demonstrate compatibility, the following criteria shall be met when applying the immunity

test levels defined in Table 1 and following the measurement procedure specified in Clause 6:

• the hearing aid operation mode shall not change; and
• the IRIL shall not exceed 55 dB SPL.

Table 1 specifies the field strengths of RF test signals to establish immunity for bystander

compatible and user compatible hearing aids. "Bystander compatibility" criteria shall be

fulfilled as a minimum requirement, whereas "user compatibility" is optional.
---------------------- Page: 11 ----------------------
– 10 – IEC 60118-13:2019 © IEC 2019
Table 1 – Field strengths of RF test signals to be used to establish immunity
for bystander compatible and user compatible hearing aids
Bystander compatibility User compatibility
IRIL ≤ 55 dB SPL for field strengths, IRIL ≤ 55 dB SPL for field strengths,
E E
V/m V/m

Frequency 0,08 to 0,65 0,65 to 0,96 0,96 to 1,4 1,4 to 2,7 2,7 to 6,0 0,08 to 0,65 0,65 to 0,96 0,96 to 1,4 1,4 to 2,0 2,0 to 2,7 2,7 to 6,0

range in
GHz
Microphone Not relevant 10 Not 10 Not Not relevant 60 Not 40 30 Not
mode relevant relevant relevant relevant
Induction Not relevant 10 Not 10 Not Not relevant 60 Not 40 30 Not
pick-up coil relevant relevant relevant relevant
mode

Directional Not relevant 10 Not 10 Not Not relevant Not relevant Not Not Not Not

relevant relevant relevant relevant relevant relevant
mode
If provided.
---------------------- Page: 12 ----------------------
IEC 60118-13:2019 © IEC 2019 – 11 –
6 Test procedures for immunity to radiated RF electromagnetic fields
6.1 General
Clause 6 describes the equipment and measurement methods for the radiated RF

electromagnetic field immunity test. Annex A provides background information for the

development of the procedures.
6.2 Test setup
An example of a suitable test arrangement is given in Figure 1.

Hearing aids whose outputs are non-acoustic, for example, bone conduction hearing aids, will

require use of an appropriate load and coupling device. Precise descriptions of measurement

setups for these types of hearing aids shall be given by the manufacturer.

Proposed testing, validation and measurement techniques, when using a GTEM cell, is to be

found in IEC 61000-4-20.
Figure 1 – Example of a test arrangement for hearing aid
immunity measurements using a GTEM cell
6.3 Hearing aid test setting

The hearing aid gain control shall be adjusted to the reference test setting (RTS), and the

other controls shall be set to the basic settings as described in 6.4.3 in IEC 60118-0:2015

("adaptive features disabled").
---------------------- Page: 13 ----------------------
– 12 – IEC 60118-13:2019 © IEC 2019
6.4 Determination of gain

For the determination of gain, the same acoustic coupler and tubing as used for the ORIL

measurement shall be used. Measurement setup for determination of gain shall be in

accordance with IEC 60118-0:2015. The gain of a hearing aid in microphone mode is

determined by applying a sinusoidal 1 kHz signal with a sound pressure level (L ) to be

p,in

swept from 30 dB SPL to 80 dB SPL at the microphone reference point of the hearing aid.

From the input-output response curve, take the acoustic sound pressure level of the output

(L ) at 55 dB input level.
p,out

For the gain of a hearing aid in directional mode, use the gain obtained in microphone mode.

The gain of a hearing aid in induction pick-up coil mode is determined by applying a

sinusoidal 1 kHz signal with a magnetic field strength level re 1 A/m (L ) in dB to be swept

H,in

from −60 dB to −10 dB at the induction pick-up coil reference point of the hearing aid,

measuring the acoustic sound pressure level (L ) at its output.
p,out
From this input-output response cu
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.