IEC 60645-1:2012

Electroacoustics - Audiometric equipment - Part 1: Equipment for pure-tone audiometry

IEC 60645-1:2012 specifies general requirements for audiometers and particular requirements for pure-tone audiometers designed for use in determining hearing threshold levels, relative to standard reference threshold levels established by means of psychoacoustic test methods. The object of this standard is to ensure:
a) That tests of hearing in the frequency range 125 Hz to 16 000 Hz on a given human ear, performed with different audiometers which comply with this standard shall give substantially the same results;
b) That the results obtained represent a valid comparison between the hearing of the ear tested and the reference threshold of hearing;
c) That audiometers are classified according to the range of test signals they generate, according to the mode of operation or according to the complexity of the range of auditory functions they test.
This third edition cancels and replaces the second edition, published in 2001, and IEC 60645-4 published in 1994. It constitutes an editorial revision.

Electroacoustique - Appareils audiométriques - Partie 1: Appareils pour l'audiométrie tonale

La CEI 60645-1:2012 spécifie des exigences générales applicables aux audiomètres et des exigences particulières applicables aux audiomètres tonaux conçus pour la détermination des seuils d'audition, par rapport aux seuils d'audition établis au moyen de méthodes d'essai psychoacoustiques. L'objet de la présente norme est de s'assurer:
a) Que les essais d'audition effectués sur une oreille humaine donnée, dans le domaine des fréquences comprises entre 125 Hz et 16 000 Hz, avec différents audiomètres satisfaisant à la présente Norme, donnent obligatoirement sensiblement les mêmes résultats;
b) Que les résultats obtenus représentent une comparaison correcte entre l'audition de l'oreille mesurée et le seuil d'audition de référence;
c) Que les audiomètres sont classés conformément au domaine des signaux d'essai qu'ils produisent, à leur mode de fonctionnement ou à la complexité du domaine des fonctions auditives qu'ils peuvent examiner.
Cette troisième édition annule et remplace la deuxième édition parue en 2001, et la CEI 60645-4 parue en 1994. Elle constitue une révision éditoriale.

General Information

• Status: Published
• Publication Date: 15-Feb-2012
• ICS: 11.040.01 - Medical equipment in general
• ICS: 17.140.50 - Electroacoustics
• Technical Committee: TC 29 - Electroacoustics
• Drafting Committee: WG 10 - TC 29/WG 10
• Current Stage: DELPUB - Deleted Publication
• Completion Date: 14-Mar-2017

Relations

• Revised: IEC 60645-1:2017 - Electroacoustics - Audiometric equipment - Part 1: Equipment for pure-tone and speech audiometry
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 60645-1
®

Edition 3.0 2012-02
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE


Electroacoustics – Audiometric equipment –
Part 1: Equipment for pure-tone audiometry

Électroacoustique – Appareils audiométriques –
Partie 1: Appareils pour l’audiométrie tonale


IEC 60645-1:2012

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IEC 60645-1

®


Edition 3.0 2012-02




INTERNATIONAL



STANDARD




NORME



INTERNATIONALE











Electroacoustics – Audiometric equipment –

Part 1: Equipment for pure-tone audiometry




Électroacoustique – Appareils audiométriques –

Partie 1: Appareils pour l’audiométrie tonale
















INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE

PRICE CODE
INTERNATIONALE

CODE PRIX V


ICS 17.140.50 ISBN 978-2-88912-915-7



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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– 2 – 60645-1 © IEC:2012
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 9
4 Requirements for specific types of fixed frequency audiometer . 12
5 General requirements . 13
5.1 General safety requirements . 13
5.2 Acoustic safety requirements . 13
5.3 Environmental conditions . 13
5.4 Warm-up time . 13
5.5 Power supply variation . 13
5.5.1 Interruption of power supply . 13
5.5.2 Mains operation . 14
5.5.3 Battery operation . 14
5.5.4 Other power supplies . 14
5.6 Electromagnetic compatibility . 14
5.7 Unwanted sound . 14
5.7.1 General . 14
5.7.2 Unwanted sound from an earphone . 14
5.7.3 Unwanted sound from a bone vibrator . 14
5.7.4 Unwanted sound radiated by an audiometer . 15
5.8 Testing of automatic-recording audiometers . 15
5.9 Interface connections . 15
6 Test signals . 15
6.1 Pure tones . 15
6.1.1 Frequency range and hearing level range . 15
6.1.2 Frequency accuracy . 16
6.1.3 Total harmonic distortion . 16
6.1.4 Rate of frequency change . 17
6.2 Frequency modulation . 17
6.3 External signal source . 17
6.3.1 Signals . 17
6.3.2 Frequency response . 17
6.3.3 Electrical sensitivity . 18
6.3.4 Reference level for external signal source . 18
6.3.5 Operator to subject speech communication . 18
6.3.6 Subject to operator speech communication . 18
6.4 Masking sound . 18
6.4.1 General . 18
6.4.2 Narrow-band noise . 18
6.4.3 Other masking sound . 20
7 Transducers . 20
7.1 Type of transducers . 20
7.2 Headband. 20

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60645-1 © IEC:2012 – 3 –
7.3 Loudspeaker . 20
8 Signal level control . 20
8.1 Marking . 20
8.2 Signal indicator . 20
8.3 Accuracy of sound pressure level and vibratory force level . 21
8.4 Hearing level control . 21
8.4.1 Manual audiometers . 21
8.4.2 Automatic-recording audiometers . 21
8.4.3 Accuracy of control . 21
8.5 Masking level control . 22
8.5.1 General . 22
8.5.2 Masking level . 22
8.5.3 Accuracy of masking levels. 22
8.5.4 Masking level range . 22
8.6 Tone switching . 22
8.6.1 Tone switch for manual audiometers . 22
8.6.2 On/off ratio for manual audiometers . 22
8.6.3 Rise/fall times for manual audiometers . 23
8.6.4 Automatic pulsed presentation . 23
8.6.5 Subject’s response time for automated test procedures . 24
8.6.6 Subject’s response system . 24
9 Reference tone . 24
9.1 General . 24
9.2 Frequencies . 24
9.3 Reference tone level control . 25
9.3.1 Range . 25
9.3.2 Intervals . 25
9.3.3 Marking . 25
9.3.4 Accuracy . 25
9.3.5 Operation . 25
10 Calibration . 25
11 Electrical output of test signals . 26
12 Audiogram format . 26
13 Test requirements to demonstrate conformity . 27
13.1 General . 27
13.2 Environmental conditions and power supply variation . 27
13.3 Electromagnetic compatibility . 27
13.4 Unwanted sound . 28
13.4.1 Unwanted sound from an earphone . 28
13.4.2 Unwanted sound from a bone vibrator . 28
13.4.3 Unwanted sound radiated by an audiometer . 29
13.5 Total harmonic distortion of test signals . 29
13.6 Signal accuracy . 29
13.6.1 Accuracy of sound pressure level and vibratory force level . 29
13.6.2 Accuracy of hearing level control . 29
13.7 Masking sound . 29
13.7.1 Narrow-band noise . 29
13.7.2 Masking level . 30

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– 4 – 60645-1 © IEC:2012
13.8 Headbands . 30
13.8.1 General . 30
13.8.2 Supra-aural and circumaural earphone headband . 30
13.8.3 Bone vibrator headband . 30
14 Maximum permitted expanded uncertainty of measurements U . 30
max
15 Marking and instruction manual . 31
15.1 Marking . 31
15.2 Instruction manual . 31
Bibliography . 33

Figure 1 – Rise/fall envelope of test tones . 24

Table 1 – Minimum facilities for fixed-frequency audiometers . 12
Table 2 – Minimum number of frequencies to be provided and the minimum range of
values of hearing level for fixed frequency audiometers . 15
Table 3 – Minimum range of values of hearing level for EHF audiometers . 16
Table 4 – Maximum permissible acoustic total harmonic distortion, for supra-aural,

circumaural, insert earphones and bone vibrators . 17
Table 5 – Narrow-band masking noise: upper and lower cut-off frequencies for a
sound pressure spectrum density level of –3 dB referred to the level at the centre
frequency of the band . 19
Table 6 – Reference standards for obtaining audiometric zero . 26
Table 7 – Symbols for the graphical presentation of hearing threshold levels . 26
Table 8 – Values of U for basic measurements . 31
max

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60645-1 © IEC:2012 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

ELECTROACOUSTICS –
AUDIOMETRIC EQUIPMENT –

Part 1: Equipment for pure-tone audiometry

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
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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 60645-1 has been prepared by IEC technical committee 29:
Electroacoustics.
This third edition cancels and replaces the second edition, published in 2001, and
IEC 60645-4 published in 1994. It constitutes an editorial revision.
The text of this standard is based on the following documents:
FDIS Report on voting
29/754/FDIS 29/757/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.

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– 6 – 60645-1 © IEC:2012
A list of all parts of the IEC 60645 series can be found, under the general title
Electroacoustics, on the IEC website.
Future standard in this series will carry the new general title as cited above. Titles of existing
standards in this series will be updated at the time of the next edition.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site 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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60645-1 © IEC:2012 – 7 –
INTRODUCTION
Developments in the field of hearing measurements for diagnostic, hearing conservation and
rehabilitation purposes have resulted in the availability of a wide range of audiometers. In
addition it is possible to consider the audiometer in terms of a set of functional units which
can be specified independently. By specifying these functional units it is then possible to
specify the performance of other audiometric equipment which use these units. IEC 60645
series consists of a number of parts. IEC 60645-1 is the first in the series and covers the
requirements for pure tone audiometers.
This standard describes equipment which is designed for the measurement of hearing in the
frequency range from 125 Hz to 16 000 Hz.
Due to the development of the later parts of IEC 60645, no reference is now made in part 1 to
the use of broad-band noise for masking. Requirements for broad-band masking noise now
only relate to its use with speech signals as described in IEC 60645-2.
The test requirements to demonstrate conformity are now specified separately. Conformance
to the specifications in this standard is demonstrated only when the result of a measurement,
extended by the actual expanded uncertainty of measurement of the testing laboratory, lies
fully within the tolerances specified in this standard. The tolerances that are to be met by the
manufacturer of an audiometer are essentially the same as in the first edition of IEC 60645-1,
while the tolerances as applicable to the testing of the audiometer are increased by U
max
compared with those of the previous edition.
IEC 60645 series consists of the following parts:
IEC 60645-1, Electroacoustics – Audiometric equipment – Part 1: Equipment for pure-tone
audiometry
IEC 60645-2, Audiometers – Part 2: Equipment for speech audiometry
IEC 60645-3, Electroacoustics – Audiometric equipment – Part 3: Test signals of short
duration
IEC 60645-4, Audiometers – Part 4: Equipment for extended high-frequency audiometry
IEC 60645-5, Electroacoustics – Audiometric equipment – Part 5: Instruments for the
measurement of aural acoustic impedance/admittance
IEC 60645-6, Electroacoustics – Audiometric equipment – Part 6: Instruments for the
measurement of otoacoustic emissions
IEC 60645-7, Electroacoustics – Audiometric equipment – Part 7: Instruments for the
measurement of auditory brainstem responses

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– 8 – 60645-1 © IEC:2012
ELECTROACOUSTICS –
AUDIOMETRIC EQUIPMENT –

Part 1: Equipment for pure-tone audiometry



1 Scope
This part of IEC 60645 specifies general requirements for audiometers and particular
requirements for pure-tone audiometers designed for use in determining hearing threshold
levels, relative to standard reference threshold levels established by means of psychoacoustic
test methods.
The object of this standard is to ensure:
a) that tests of hearing in the frequency range 125 Hz to 16 000 Hz on a given human ear,
performed with different audiometers which comply with this standard shall give
substantially the same results;
b) that the results obtained represent a valid comparison between the hearing of the ear
tested and the reference threshold of hearing;
c) that audiometers are classified according to the range of test signals they generate,
according to the mode of operation or according to the complexity of the range of auditory
functions they test.
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 60268-3, Sound system equipment – Part 3: Amplifiers
IEC 60318-1, Electroacoustics – Simulators of human head and ear – Part 1: Ear simulator for
the measurement of supra-aural and circumaural earphones
IEC 60318-3, Electroacoustics – Simulators of human head and ear – Part 3: Acoustic coupler
for the calibration of supra-aural earphones used in audiometry
IEC 60318-4, Electroacoustics – Simulators of human head and ear – Part 4: Occluded-ear
simulator for the measurement of earphones coupled to the ear by means of ear inserts
IEC 60318-5, Electroacoustics – Simulators of human 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 60318-6, Electroacoustics – Simulators of human head and ear – Part 6: Mechanical
coupler for the measurement of bone vibrators
IEC 60601-1, Medical electrical equipment – Part 1: General requirements for basic safety
and essential performance

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60645-1 © IEC:2012 – 9 –
IEC 60601-1-2, Medical electrical equipment – Part 1-2: General requirements for basic safety
and essential performance – Collateral standard: Electromagnetic compatibility –
Requirements and tests
IEC 60645-2, Audiometers – Part 2: Equipment for speech audiometry
IEC 61672-1, Electroacoustics – Sound level meters – Part 1: Specifications
ISO 266, Acoustics – Preferred frequencies
ISO 389-1, Acoustics – Reference zero for the calibration of audiometric equipment – Part 1:
Reference equivalent threshold sound pressure levels for pure tones and supra-aural
earphones
ISO 389-2, Acoustics – Reference zero for the calibration of audiometric equipment – Part 2:
Reference equivalent threshold sound pressure levels for pure tones and insert earphones
ISO 389-3, Acoustics – Reference zero for the calibration of audiometric equipment – Part 3:
Reference equivalent threshold force levels for pure tones and bone vibrators
ISO 389-4:1994, Acoustics – Reference zero for the calibration of audiometric
...