Electroacoustics - Measurement of real-ear acoustical performance characteristics of hearing aids

This International Standard gives recommendations and requirements for the measurement
and estimation of the real-ear acoustical performance characteristics of air-conduction
hearing aids and for the measurement of certain acoustic properties of the ear related to the
application of hearing aids.
Measurements of real-ear acoustical characteristics of hearing aids which apply non-linear or
analytical processing techniques are valid only for the test signals used and conditions
employed.
The purpose of this standard is to ensure that measurements of real-ear acoustical
performance characteristics of a given hearing aid on a given human ear can be replicated in
other locations with other test equipment.

Elektroakustik - Messung der Kenndaten von Hörgeräten am menschlichen Ohr

Électroacoustique - Mesure des caractéristiques de performances acoustiques des appareils de correction auditive sur une oreille réelle

L'IEC 61669:2015 donne les recommandations et les exigences relatives au mesurage et à l'estimation des caractéristiques de performances acoustiques sur une oreille réelle des appareils de correction auditive à conduction aérienne, et au mesurage de certaines propriétés acoustiques de l'oreille liées à l'application des appareils de correction auditive. Les mesurages des caractéristiques acoustiques des appareils de correction auditive sur une oreille réelle qui appliquent des techniques opératoires non linéaires ou analytiques sont valables uniquement pour les signaux d essai utilisés et les conditions expérimentales. La présente norme a pour objet de s'assurer que les mesurages des caractéristiques de performances acoustiques sur une oreille réelle d'un appareil de correction auditive donné, effectués sur une oreille humaine donnée peuvent être répétés dans d autres emplacements avec un autre appareillage d'essai. Cette deuxième édition annule et remplace la première édition de l'IEC 61669:2001 et la première édition de l'ISO 12124:2001. Cette édition consiste en une révision technique.

Elektroakustika - Meritve akustičnih karakteristik slušnih pripomočkov v človeškem ušesu

Ta mednarodni standard daje priporočila in zahteve za meritve in ocene akustičnih karakteristik slušnih pripomočkov v človeškem ušesu za merjenje nekaterih akustičnih lastnosti ušesa, povezanih z uporabo slušnih pripomočkov.
Meritve akustičnih karakteristik slušnih pripomočkov, ki uporabljajo nelinearne ali analitične tehnike obdelave, veljajo samo za uporabljene preskusne signale v pogojih merjenja.
Namen tega standarda je zagotoviti, da je mogoče meritve akustičnih karakteristik danega slušnega pripomočka na danem človeškem ušesu ponoviti tudi na drugih lokacijah z drugo preskusno opremo.

General Information

Status
Published
Publication Date
09-Mar-2016
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
02-Mar-2016
Due Date
07-May-2016
Completion Date
10-Mar-2016

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SLOVENSKI STANDARD
SIST EN 61669:2016
01-april-2016
1DGRPHãþD
SIST EN 61669:2002
(OHNWURDNXVWLND0HULWYHDNXVWLþQLKNDUDNWHULVWLNVOXãQLKSULSRPRþNRYY
þORYHãNHPXãHVX

Electroacoustics - Measurement of real-ear acoustical performance characteristics of

hearing aids
Ta slovenski standard je istoveten z: EN 61669:2016
ICS:
11.180.15 3ULSRPRþNL]DJOXKHRVHEHLQ Aids for deaf and hearing
RVHEH]RNYDURVOXKD impaired people
17.140.50 Elektroakustika Electroacoustics
SIST EN 61669:2016 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 61669:2016
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SIST EN 61669:2016
EUROPEAN STANDARD EN 61669
NORME EUROPÉENNE
EUROPÄISCHE NORM
February 2016
ICS 17.140.50 Supersedes EN 61669:2001
English Version
Electroacoustics - Measurement of real-ear acoustical
performance characteristics of hearing aids
(IEC 61669:2015)

Électroacoustique - Mesure des caractéristiques de Elektroakustik - Messung der Kenndaten von Hörgeräten

performances acoustiques des appareils de correction am menschlichen Ohr
auditive sur une oreille réelle (IEC 61669:2015)
(IEC 61669:2015)

This European Standard was approved by CENELEC on 2015-12-09. CENELEC 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 CENELEC 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 CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the

same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,

Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,

Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,

Turkey and the United Kingdom.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels

© 2016 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.

Ref. No. EN 61669:2016 E
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SIST EN 61669:2016
EN 61699:2016
European foreword
The text of document 29/886/FDIS, future edition 2 of IEC 61699, prepared by

IEC/TC 29 "Electroacoustics" was submitted to the IEC-CENELEC parallel vote and approved by

CENELEC as EN 61699:2016.
The following dates are fixed:
(dop) 2016-09-09
• latest date by which the document has to be
implemented at national level by
publication of an identical national
standard or by endorsement
(dow) 2018-12-09
• latest date by which the national
standards conflicting with the
document have to be withdrawn
This document supersedes EN 61699:2001.

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such

patent rights.
Endorsement notice

The text of the International Standard IEC 61699:2015 was approved by CENELEC as a European

Standard without any modification.

In the official version, for Bibliography, the following notes have to be added for the standards indicated:

IEC 60118-0 NOTE Harmonized as EN 60118-0.
IEC 60118-7 NOTE Harmonized as EN 60118-7.
IEC 60118-8 NOTE Harmonized as EN 60118-8.
IEC 60118-15 NOTE Harmonized as EN 60118-15.
IEC 60318-4 NOTE Harmonized as EN 60318-4.
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SIST EN 61669:2016
EN 61699:2016
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

The following documents, in whole or in part, are normatively referenced in this document and are

indispensable for its application. For dated references, only the edition cited applies. For undated

references, the latest edition of the referenced document (including any amendments) applies.

NOTE 1 When an International Publication has been modified by common modifications, indicated by (mod), the relevant

EN/HD applies.

NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available here:

www.cenelec.eu.
Publication Year Title EN/HD Year
IEC 60318-5 - Electroacoustics - Simulators of human EN 60318-5 -
head and ear -- Part 5: 2 cm³ coupler for
the measurement of hearing aids and
earphones coupled to the ear by means of
ear inserts
IEC 60601-1 - Medical electrical equipment -- Part 1: EN 60601-1 -
General requirements for basic safety and
essential performance
IEC 60601-1-2 - Medical electrical equipment -- Part 1-2: EN 60601-1-2 -
General requirements for basic safety and
essential performance - Collateral
standard: Electromagnetic disturbances -
Requirements and tests
IEC 60942 - Electroacoustics - Sound calibrators EN 60942 -
IEC 61260-1 - Electroacoustics - Octave-band and EN 61260-1 -
fractional-octave-band filters -- Part 1:
Specifications
ISO 266 - Acoustics - Preferred frequencies EN ISO 266 -
ISO 8253-2 - Acoustics - Audiometric test methods - Part EN ISO 8253-2 -
2: Sound field audiometry with pure-tone
and narrow-band test signals
ISO/TR 25417 - Acoustics_- Definitions of basic quantities - -
and terms
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SIST EN 61669:2016
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SIST EN 61669:2016
IEC 61669
Edition 2.0 2015-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Electroacoustics – Measurement of real-ear acoustical performance
characteristics of hearing aids
Électroacoustique – Mesure des caractéristiques de performances acoustiques
des appareils de correction auditive sur une oreille réelle
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 17.140.50 ISBN 978-2-8322-2994-1

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
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SIST EN 61669:2016
– 2 – IEC 61669:2015 © IEC 2015
CONTENTS

FOREWORD ........................................................................................................................... 4

INTRODUCTION ..................................................................................................................... 6

1 Scope .............................................................................................................................. 7

2 Normative references ...................................................................................................... 7

3 Terms and definitions ...................................................................................................... 8

4 Test setup diagrams ...................................................................................................... 13

5 Limitations ..................................................................................................................... 15

6 Test equipment .............................................................................................................. 16

6.1 Safety requirements .............................................................................................. 16

6.2 Ambient conditions................................................................................................ 16

6.3 Test signal ............................................................................................................ 16

6.4 Sound field source ................................................................................................ 17

6.5 Coupled sound source .......................................................................................... 17

6.6 Test signal range .................................................................................................. 17

6.7 Test signal level indication .................................................................................... 17

6.8 Equalization .......................................................................................................... 17

6.9 Frequency ............................................................................................................. 17

6.10 Harmonic distortion ............................................................................................... 17

6.11 Probe microphone measurement ........................................................................... 17

6.12 Noise floor of probe microphone measurement ..................................................... 17

6.13 Attenuation of probe microphone to external signals ............................................. 18

6.14 Analysis characteristics......................................................................................... 18

6.15 Output indication ................................................................................................... 18

6.16 Graphical printout ................................................................................................. 18

7 Test conditions .............................................................................................................. 19

7.1 Ambient conditions in the test space ..................................................................... 19

7.2 Background noise ................................................................................................. 19

7.3 Acoustical properties ............................................................................................ 19

7.4 Sound field characteristics .................................................................................... 19

7.5 Calibration ............................................................................................................ 19

7.6 Equalization .......................................................................................................... 19

7.6.1 General ......................................................................................................... 19

7.6.2 Substitution method ....................................................................................... 19

7.6.3 Modified pressure method – Stored equalization ............................................ 20

7.6.4 Modified pressure method – Concurrent equalization ..................................... 20

7.7 Test signal level .................................................................................................... 20

7.8 Location of the subject .......................................................................................... 20

7.9 Location of the tester ............................................................................................ 20

7.10 Location of the field reference point ...................................................................... 20

7.11 Location of the measurement point ....................................................................... 21

7.12 Instructions to the subject ..................................................................................... 21

7.13 Location and coupling of the hearing aid ............................................................... 21

7.14 Operating conditions for the hearing aid ................................................................ 21

8 Measurements ............................................................................................................... 21

8.1 General ................................................................................................................. 21

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SIST EN 61669:2016
IEC 61669:2015 © IEC 2015 – 3 –

8.2 Real-ear unaided response (REUR) curve............................................................. 21

8.3 Real-ear unaided gain (REUG) curve .................................................................... 22

8.4 Real-ear occluded response (REOR) curve ........................................................... 22

8.5 Real-ear occluded gain (REOG) curve .................................................................. 22

8.6 Real-ear aided response (REAR) curve................................................................. 22

8.7 Real-ear aided gain (REAG) curve ........................................................................ 23

8.8 Real-ear insertion gain (REIG) curve .................................................................... 23

8.9 Real-ear to coupler difference (RECD) curve ........................................................ 23

8.10 Real-ear to dial difference (REDD) curve .............................................................. 23

9 Measurement uncertainty for the performance requirements of Clause 6 ....................... 24

Annex A (informative) Positioning the probe microphone sound inlet at the

measurement point ............................................................................................................... 25

A.1 General ................................................................................................................. 25

A.2 Visual positioning .................................................................................................. 25

A.3 Acoustically-assisted positioning ........................................................................... 25

A.4 Acoustic positioning – Method 1 ............................................................................ 26

A.5 Acoustic positioning – Method 2 ............................................................................ 26

A.6 Geometrical positioning ........................................................................................ 26

Annex B (informative) Issues in RECD measurement and application .................................. 27

B.1 General ................................................................................................................. 27

B.2 Influence of the coupled sound source .................................................................. 27

B.3 Estimating ear canal SPL produced by a hearing aid............................................. 30

B.4 Correcting an HL audiogram obtained with an insert earphone and a

standard eartip ...................................................................................................... 32

B.5 Correcting an HL audiogram obtained with an insert earphone and a custom

earmould............................................................................................................... 32

Annex C (informative) Relationship between tolerance interval, corresponding

acceptance interval and the maximum permitted uncertainty of measurement ....................... 34

Bibliography .......................................................................................................................... 35

Figure 1 – Test set-up ........................................................................................................... 14

Figure 2 – Real-ear measurement arrangement .................................................................... 15

Figure B.1 – Computer-simulated ECLD for an average adult ear ......................................... 29

Figure B.2 – Computer-simulated ECLD for an average 3-month old child’s ear .................... 29

Figure B.3 – Computer-simulated error in estimating SPL in an average adult ear ................ 31

Figure B.4 – Computer-simulated error in estimating SPL in an average 3-month old

child’s ear ............................................................................................................................. 31

Figure B.5 – Computer-simulated HL correction for an average 3 month old child’s ear ....... 33

Figure C.1 – Relationship between tolerance interval, corresponding acceptance

interval and the maximum permitted uncertainty of measurement ......................................... 34

Table 1 – Tolerance limits, acceptance limits and U for basic measurements ................. 24

max
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SIST EN 61669:2016
– 4 – IEC 61669:2015 © IEC 2015
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTROACOUSTICS –
MEASUREMENT OF REAL-EAR ACOUSTICAL
PERFORMANCE CHARACTERISTICS OF HEARING AIDS
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 61669 has been prepared by IEC technical committee 29:

Electroacoustics.

This second edition cancels and replaces the first edition of IEC 61669:2001 and the first

edition of ISO 12124:2001. This edition constitutes a technical revision.

This edition includes the following significant technical changes with respect to

IEC 61669:2001 and ISO 12124:2001:

a) the addition of the International Speech Test Signal as a preferred speech-like stimulus;

b) definitions and test methods for the real-ear to dial difference;
c) definitions and test methods for the real-ear to coupler difference and

d) an annex dealing with issues in the measurement and application of the real-ear to

coupler difference;
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SIST EN 61669:2016
IEC 61669:2015 © IEC 2015 – 5 –
The text of this standard is based on the following documents:
FDIS Report on voting
29/886/FDIS 29/893/RVD

Full information on the voting for the approval of this standard can be found in the report on

voting indicated in the above table.

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

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

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

related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
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SIST EN 61669:2016
– 6 – IEC 61669:2015 © IEC 2015
INTRODUCTION

The performance characteristics of hearing aids in actual use can differ significantly from

those determined in accordance with standards such as IEC 60118-0, and IEC 60118-7, due

to differing acoustic influence and coupling presented by individual ears. Measuring methods

that take into account the acoustic coupling and the acoustic influence of the individual

wearer on the performance of hearing aids are therefore important in the fitting of these

devices. Such measuring methods have come to be known as “real-ear measurements” and

are sometimes performed clinically in less than ideal acoustic environments. The accuracy

and repeatability of measurements made under such conditions are complex functions of the

sound field, the test environment, the nature of the test signal, the hearing aid under

evaluation, the method of test signal control, the location of the sound field source, the nature

of the data acquisition, analysis and presentation as well as the degree of subject movement

permitted.

This standard provides definitions for terms used in the measurement of real-ear performance

characteristics of hearing aids, provides procedural and reporting guidelines, and identifies

essential characteristics to be reported by the manufacturer of equipment used for this

purpose. Acceptable tolerances for the control and measurement of sound pressure levels

are indicated. Where possible, sources of error have been identified and suggestions provided

for their management.
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SIST EN 61669:2016
IEC 61669:2015 © IEC 2015 – 7 –
ELECTROACOUSTICS –
MEASUREMENT OF REAL-EAR ACOUSTICAL
PERFORMANCE CHARACTERISTICS OF HEARING AIDS
1 Scope

This International Standard gives recommendations and requirements for the measurement

and estimation of the real-ear acoustical performance characteristics of air-conduction

hearing aids and for the measurement of certain acoustic properties of the ear related to the

application of hearing aids.

Measurements of real-ear acoustical characteristics of hearing aids which apply non-linear or

analytical processing techniques are valid only for the test signals used and conditions

employed.

The purpose of this standard is to ensure that measurements of real-ear acoustical

performance characteristics of a given hearing aid on a given human ear can be replicated in

other locations with other test equipment.
2 Normative references

The following documents, in whole or in part, are normatively referenced in this document and

are indispensable for its application. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any
amendments) applies.

IEC 60601-1, Medical electrical equipment – Part 1: General requirements for basic safety

and essential performance

IEC 60601-1-2, Medical electrical equipment – Part 1-2: General requirements for basic safety

and essential performance – Collateral Standard: Electromagnetic disturbances –
Requirements and tests

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 60942, Electroacoustics – Sound calibrators

IEC 61260-1, Electroacoustics – Octave-band and fractional-octave-band filters – Part 1:

Specifications
ISO 266, Acoustics – Preferred frequencies

ISO 8253-2, Acoustics – Audiometric test methods – Part 2: Sound field audiometry with pure-

tone and narrow-band test signals
ISO/TR 25417, Acoustics – Definitions of basic quantities and terms
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SIST EN 61669:2016
– 8 – IEC 61669:2015 © IEC 2015
3 Terms and definitions

For the purpose of this document, the terms and definitions of ISO/TR 25417 and the

following apply:
3.1
test signal
acoustic signal at the field reference point
3.2
coupled sound source

earphone or hearing aid receiver and any tubing used to couple its acoustic output, without

leakage, to the ear canal or the cavity of a coupler
3.3
free sound field

sound field where the boundaries of the room exert a negligible effect on the sound waves

Note 1 to entry: In practice, a free sound field is a field in which the influence of reflections at the boundaries or

other disturbing objects is negligible over the frequency range of interest.
[SOURCE: ISO 8253-2:2009, 3.12, modified (addition of note to entry)]
3.4
quasi-free sound field

sound field where the boundaries of the room exert only a moderate effect on the sound

waves
[SOURCE: ISO 8253-2:2009, 3.13]
3.5
subject
person in whose ear the hearing aid performance is characterized
3.6
subject reference point

point bisecting the line joining the centres of the openings of the ear canals of the subject (at

the junction between concha and ear canal)

Note 1 to entry: In cases where severe head shape abnormality or asymmetry make it difficult to determine the

reference point of the subject, the subject reference point used should be stated.

3.7
subject test position

position with subject seated in a reproducible upright position with the head erect and the

subject reference point located on the test axis at the working distance
3.8
test axis

line through the centre of the surface from which sound exits the sound field source and in the

direction of maximum acoustic radiation
SEE: Figure 1.
3.9
test point

reproducible position on the test axis at which the subject reference point is located for test

purposes
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SIST EN 61669:2016
IEC 61669:2015 © IEC 2015 – 9 –
SEE: Figure 1.
3.10
working distance

distance from the subject reference point to the plane of the mounting ring or protective grille

of the sound field source measured along the test axis
SEE: Figure 1.
3.11
SPL
sound pressure level

ten times the logarithm to the base 10 of the ratio of the square of the sound pressure, p, to

the square of a reference value, p
2 2
L = 10lg(p /p ) dB
p 0
where the reference value, p , is 20 µPa
Note 1 to entry: Sound pressure level is expressed in decibels.

Note 2 to entry: Because of practical limitations of the measuring instruments, p is always understood to denote

the square of a frequency-weighted, frequency-band-limited or time-weighted sound pressure.

Note 3 to entry: This note applies to the French version only.
[SOURCE: ISO/TR 25417:2007, 1.2]
3.12
BSPL
band sound pressure level
SPL for a specified frequency band
Note 1 to entry: This note applies to the French language only.
3.13
test signal level
SPL of the test signal at the field reference point

Note 1 to entry: For broad-band signals the bandwidth of the SPL measurement and the BSPL as a function of

frequency should be specified and stated.
3.14
equalization

process of controlling the test signal level as a function of frequency such that it does not vary

from the desired level
3.14.1
concurrent equalization
real time equalization

equalization performed at the time of measurement based on the monitoring of the test signal

level
3.14.2
stored equalization

equalization performed at the time of measurement based on data recorded during a prior

measurement of the sound field
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SIST EN 61669:2016
– 10 – IEC 61669:2015 © IEC
...

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