EN 60118-0:1993
(Main)Hearing aids - Part 0: Measurement of electroacoustical characteristics
Hearing aids - Part 0: Measurement of electroacoustical characteristics
Defines the measurement of physical performance characteristics of air-conduction hearing aids based on a free-field technique and measured with an ear simulator. Describes methods of measurement for evaluation of the electroacoustical characteristics of hearing aids.
Hörgeräte - Teil 0: Messung der elektroakustischen Eigenschaften
Appareils de correction auditive - Partie 0: Méthodes de mesure des caractéristiques électroacoustiques
Décrit la mesure des caractéristiques physiques des appareils de correction auditive à conduction aérienne, fondée sur une technique de champ acoustique libre et utilisant un simulateur d'oreille. Décrit des méthodes de mesure pour l'évaluation des caractéristiques électroacoustiques des appareils de correction auditive.
Hearing aids - Part 0: Measurement of electroacoustical characteristics (IEC 60118-0:1983)
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SLOVENSKI STANDARD
01-september-2002
Hearing aids - Part 0: Measurement of electroacoustical characteristics (IEC 60118-
0:1983)
Hearing aids -- Part 0: Measurement of electroacoustical characteristics
Hörgeräte -- Teil 0: Messung der elektroakustischen Eigenschaften
Appareils de correction auditive -- Partie 0: Méthodes de mesure des caractéristiques
électroacoustiques
Ta slovenski standard je istoveten z: EN 60118-0:1993
ICS:
11.180.15 3ULSRPRþNL]DJOXKHRVHEHLQ Aids for deaf and hearing
RVHEH]RNYDURVOXKD impaired people
17.140.50 Elektroakustika Electroacoustics
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
NORME CEI
INTERNATIONALE IEC
118-0
INTERNATIONAL
Deuxième édition
STAN DARD
Second edition
de correction auditive
Appareils
Partie zéro:
Méthodes de mesure des caractéristiques
électroacoustiques
Hearing aids
Part 0:
Measurement of electroacoustical
characteristics
de reproduction Copyright - all rights reserved
© CEI 1983 Droits réservés —
Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in
utilisée sous quelque forme que ce soit et par aucun pro- any form or by any means, electronic or mechanical,
cédé, électronique ou mécanique, y compris la photocopie et including photocopying and microfilm, without permission
les microfilms, sans l'accord écrit de l'éditeur. in writing from the publisher.
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118-0 © IEC 1983 - 3 -
CONTENTS
Page
FOREWORD 7
PREFACE 7
Clause
1. Scope
2. Object 11
3. General conditions 13
4. Explanation of terms 13
4.1 Ear simulator 13
4.2 Substitution method 13
4.3 Comparison method
4.4 Pressure method 13
4.5 Simulated in situ method 13
4.6 13 Reference orientation (of a hearing aid)
4.7 Reference point (of a hearing aid)
4.8 Test point 15
4.9 Supply voltage 15
4.10 Acoustic gain 15
4.11 Full-on acoustic gain (frequency response curve)
4.12 Maximum acoustic gain at a specified frequency
4.13 Saturation sound pressure level (frequency response curve) 15
4.14 Maximum saturation sound pressure level
4.15 Output sound pressure level for an input sound pressure level of 90 dB (OSPL 90) at a specified frequency (or
frequencies) 15
4.16 Reference test frequency
4.17 Reference test gain control position 17
4.18 Reference test gain
4.19 Frequency response
4.20 Comprehensive frequency response curves 17
4.21 Basic frequency response curve
4.22 Steady state input-output graph
5. Test equipment 17
5.1 Acoustical requirements for the test enclosure
5.2 Sound field at the test point
5.3 Ear simulator 19
5.4 Equipment for the measurement of sound pressure level in the ear simulator 19
5.5 Equipment for automatic sweep frequency recording
5.6 Calibration of free-field sound pressure level 21
6. Test conditions
6.1 Choice of test point
6.2 Calibrating the sound field 23
6.3 Locating the hearing aid for tests
6.4 Normal operating conditions for the hearing aid 25
7. Measurements 27
7.1 Maximum saturation sound pressure level
7.2 Output sound pressure level frequency response for an input SPL of 90 dB 27
7.3 Full-on acoustic gain frequency response
7.4 Comprehensive frequency responses and basic frequency response
7.5 Effect of tone control position on the basic frequency response 31
7.6 Effect of gain control position on frequency response 31 .
7.7 Characteristics of the gain control 33
7.8 Effect on the full-on acoustic gain of va riation of battery or supply voltage 33
7.9 riation of internal resistance of battery or supply 33
Effect on the full-on acoustic gain of va
7.10 Effect on OSPL 90 of variation of battery or supply voltage 35
7.11 Battery current 35
7.12 Measurement of amplitude non-linearities in hearing aids 35
118-0 © I E C 1983 - 5 -
Page
Clause
7.13 Effect on amplitude non-linearities of variation of battery or supply voltage and internal impedance
7.14 Internal noise generated in the hearing aid
43 7.15 Characteristics of hearing aid with induction pick-up coil input
47 7.16 Characteristics of hearing aids with automatic gain control circuits
8. Frequency response recording chart
APPENDIX A — Harmonic and intermodulation distortion
- 7 -
118-0 © I E C 1983
INTERNATIONAL ELECTROTECHNICAL COMMISSION
HEARING AIDS
Part 0: Measurement of electroacoustical characteristics
FOREWORD
1) The formal decisions or agreements of the I EC on technical matters, prepared by Technical Committees on which all the
National Committees having a special interest therein are represented, express, as nearly as possible, an international
consensus of opinion on the subjects dealt with.
2) They have the form of recommendations for inte rnational use and they are accepted by the National Committees in that
sense.
3) In order to promote international unification, the I EC expresses the wish that all National Committees should adopt the
text of the I EC recommendation for their national rules in so far as national conditions will permit. Any divergence
between the I EC recommendation and the corresponding national rules should, as far as possible, be clearly indicated in
the latter.
PREFACE
This standard has been prepared by I EC Technical Committee No. 29: Electroacoustics.
It forms Part 0 of the second edition of I EC Publication 118 which is currently under revision and which will be issued with
a modified generic title: Hearing Aids.
This second edition will comprise the following parts:
Publication 118-0 Part
0: Measurement of Electroacoustical Characteristics.
Publication 118-1 Part 1: Hearing Aids with Induction Pick-up Coil Input.
Publication 118-2 Pa rt 2: Hearing Aids with Automatic Gain Control Circuits.
Publication 118-3 Pa rt 3: Hearing Aid Equipment not Entirely Worn on the Listener.
Publication 118-4 Pa rt 4: Magnetic Field Strength in Audio-frequency Induction Loops for Hearing Aid Purposes.
Publication 118-5 Pa rt 5: Nipples for Insert Earphones.
Publication 118-6 Pa 6: External Electrical Inputs to Personal Hearing Aids. (In preparation.)
rt
Publication 118-7 Part 7: Measurement of Performance Characteristics of Hearing Aids for Quality Inspection for Delivery
Purposes.
Publication 118-8 Part 8: Methods of Measurement of Perform ance Characteristics of Hearing Aids under Simulated in situ
Working Conditions. (In preparation.)
Publication 118-9 Part 9: Method of Measurement of Characteristics of Hearing Aids with Bone Vibrator Outputs. (In
preparation.)
Publication 118-10 Part 10: Standard Practices for Hearing Aid Specification. (Under consideration.)
Publication 118-11 Pa
rt 11: Symbols and other Markings on Hearing Aids and Related Equipment.
A first draft was discussed at the meeting held in Sydney in 1980. As a result of this meeting, a draft, Document 29(Central
Office)122, was submitted to the Na tional Committees for approval under the Six Months' Rule in December 1980.
- 9 -
118-0 © I E C 1983
The National Committees of the following countries voted explicitly in favour of publication:
Romania
Austria Germany
South Africa
Hungary Belgium
(Republic of)
Canada Israel
Italy Spain
Czechoslovakia
Sweden
Denmark Japan
Turkey
Egypt Netherlands
Norway United Kingdom
German Democratic
United States of America
Republic Poland
Other I EC publications quoted in this standard:
68: Basic Environmental Testing Procedures.
Publications Nos.
118: Hearing Aids.
1: Hearing Aids with Induction Pick-up Coil.
118-1: Part
118-2: Part 2: Hearing Aids with Automatic Gain Control Circuits.
7: Measurement of the Performance Characteristics of Hearing Aids for Quality Inspection
118-7: Part
for Delivery Purposes.
8: Methods of Measurement of Performance Characteristics of Hearing Aids under
118-8: Part
Simulated in situ Working Conditions (in preparation).
126: I EC Reference Coupler for the Measurement of Hearing Aids Using Earphones Coupled to the
Ear by Means of Ear Inserts.
225: Octave, Half-octave and Third-octave Band Filters Intended for the Analysis of Sounds and
Vibrations.
263: Scales and Sizes for Plotting Frequency Characteristics and Polar Diagrams.
rts.
711: Occluded-ear Simulator for the Measurement of Earphones Coupled to the Ear by Ear Inse
— 11 —
118-0 © I E C 1983
HEARING AIDS
Part 0: Measurement of electroacoustical characteristics
1. Scope
This standard describes the measurement of physical performance characteristics of air-
conduction hearing aids based on a free-field technique and measured with an ear simulator.
2. Object
2.1 The object of this standard is to describe methods of measurement for the evaluation of the
electroacoustical characteristics of hearing aids.
The methods are chosen first of all to be practical and reproducible, and consequently they
are based on fixed parameters chosen, to a ce rtain extent, arbitrarily. This should be taken into
consideration when comparisons are being made between test results for hearing aids of
different models and manufacture, and in each case it is advisable to examine to what extent
the arbitrarily chosen parameters will influence the comparison of such test results.
2.2 The test results obtained by the methods specified in this standard express the performance
under the conditions of the test and may deviate substantially from the performance of the
hearing aid under practical conditions of use.
2.3 It is not the purpose of this standard to restrict the variety of hearing aid performance and
characteristics available, nor to inhibit in any way advances in the state of the art.
2.4 The most significant change in this standard is the use of an ear simulator in accordance with
I E C Publication 711: Occluded-ear Simulator for the Measurement of Earphones Coupled to
the Ear by Ear Inserts, rather than an acoustic coupler, I E C Publication 126: I EC Reference
Coupler for the Measurement of Hearing Aids Using Earphones Coupled to the Ear by Means
of Ear Inserts. The effect of this change will be to give an apparent significant increase, at some
frequencies, of both gain and saturation output levels over the results obtained when
measurements are made with the acoustic coupler. Results obtained by using the methods
described in this standard cannot therefore be directly compared with those previously obtained
using the first edition of I E C Publication 118: Recommended Methods for Measurement of the
Electroacoustical Characteristics of Hearing Aids, or I E C Publication 118-7: Hearing Aids,
7: Measurement of Performance Characteristics of Hearing Aids for Quality Inspection for
Part
rt 8: Methods of Measurement of Performance
Delivery Purposes, or I E C Publication 118-8: Pa
in situ Working Conditions. (In preparation.)
Characteristics of Hearing Aids under Simulated
— 13 —
118-0 © IEC 1983
3. General conditions
3.1 Throughout this standard all sound pressure levels specified are referred to 20 µPa. When
appropriate, sound pressure level will be abbreviated to SPL.
3.2 Reference is made to IEC Publication 711 (1981): Occluded Ear Simulator for the
rts.
Measurement of Earphones Coupled to the Ear by Ear Inse
3.3 Test results obtained by the substitution method using point-by-point measurement shall be
considered basic and should be used as a reference when results from the comparison method
and the pressure method are being interpreted (see Sub-clauses 4.2, 4.3 and 4.9).
4. Explanation of terms
4.1 Ear simulator
An ear simulator is a device for measuring the output sound pressure of an earphone under
well-defined loading conditions in a specified frequency range. It consists essentially of a cavity
of specified volume, acoustic load networks, and a calibrated microphone. The location of the
microphone is chosen so that the sound pressure at the microphone corresponds approximately
to the sound pressure generated at the human eardrum (see I E C Publication 711).
4.2 Substitution method
A method of measurement in which the hearing aid and the microphone employed to
measure the free-field sound pressure are placed alternatively at the same point in the sound
field.
4.3 Comparison method
A method of measurement in which the hearing aid and the microphone employed to
measure the free-field sound pressure, are placed simultaneously at two acoustically equivalent
points in the sound field.
4.4 Pressure method
A method of measurement in which the input sound pressure level is controlled close to the
sound entry of the hearing aid by a pressure calibrated controlling microphone, thus substan-
tially eliminating diffraction effects from the hearing aid.
4.5 Simulated in situ method
A method of measurement in which the hearing aid is mounted upon an artificial head and
torso in order to simulate the acoustical effects of an average adult wearer.
4.6 Reference o rientation (of a hearing aid)
The orientation of a hearing aid in the test enclosure with respect to the sound source, which
corresponds to the o rientation of a hearing aid under actual use on a person facing the sound
source.
— 15 —
118-0 © I E C 1983
4.7 Reference point (of a hearing aid)
A point on the hearing aid chosen for the purpose of defining its position.
4.8 Test point
A position in the test enclosure to which the measurements of the free-field sound pressure
level are referred and at which the reference point of the hearing aid is located for test purposes.
Supply voltage
4.9
The voltage at the battery terminals of the hearing
...
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