IEC TS 60318-7:2017

IEC TS 60318-7 ®
Edition 2.0 2017-04
TECHNICAL
SPECIFICATION
colour
inside
Electroacoustics – Simulators of human head and ear –
Part 7: Head and torso simulator for the measurement of air-conduction hearing
aids
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.

IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé Fax: +41 22 919 03 00
CH-1211 Geneva 20 info@iec.ch
Switzerland www.iec.ch
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 corrigenda or an amendment might have been published.

IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing 20 000 terms and definitions in
Technical Specifications, Technical Reports and other English and French, with equivalent terms in 16 additional
documents. Available for PC, Mac OS, Android Tablets and languages. Also known as the International Electrotechnical
iPad. Vocabulary (IEV) online.

IEC publications search - www.iec.ch/searchpub IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a 65 000 electrotechnical terminology entries in English and
variety of criteria (reference number, text, technical French extracted from the Terms and Definitions clause of
committee,…). It also gives information on projects, replaced IEC publications issued since 2002. Some entries have been
and withdrawn publications. collected from earlier publications of IEC TC 37, 77, 86 and

CISPR.
IEC Just Published - webstore.iec.ch/justpublished

Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc
details all new publications released. Available online and If you wish to give us your feedback on this publication or
also once a month by email. need further assistance, please contact the Customer Service
Centre: csc@iec.ch.
IEC TS 60318-7 ®
Edition 2.0 2017-04
TECHNICAL
SPECIFICATION
colour
inside
Electroacoustics – Simulators of human head and ear –

Part 7: Head and torso simulator for the measurement of air-conduction hearing

aids
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 17.140.50 ISBN 978-2-8322-4166-0

– 2 – IEC 60318-7:2017  IEC 2017
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 Construction . 11
4.1 General . 11
4.2 Geometrical dimensions of the manikin . 12
4.2.1 Head and torso . 12
4.2.2 Pinna simulators for hearing aid measurements . 13
4.2.3 Ear canal extension . 14
4.2.4 Ear simulator . 16
4.2.5 Materials . 17
4.3 Acoustical characteristics of the manikin . 17
4.3.1 Free-field frequency response . 17
4.3.2 Diffuse-field frequency response . 19
4.3.3 Acceptance intervals . 20
4.3.4 Openings . 20
5 Calibration . 21
5.1 Reference environmental conditions . 21
5.2 Calibration method . 21
5.2.1 General . 21
5.2.2 Test signal, test space and measurement equipment . 21
5.2.3 Measurement of sound pressure level. 22
5.2.4 Alignment of manikin azimuth and elevation . 23
5.2.5 Test for sound leakage . 23
6 Marking and instruction manual . 23
6.1 Markings of the manikin . 23
6.2 Instruction manual . 23
7 Maximum permitted uncertainty of measurements . 24
Annex A (informative) Design example of an anatomically shaped manikin . 26
Annex B (informative) Design examples of a geometrically shaped manikin . 27
Annex C (informative) Relationship between tolerance interval, corresponding
acceptance interval and the maximum permitted uncertainty of measurement . 29
Annex D (informative) 3D representation of example pinna simulators . 30
D.1 Background. 30
D.2 Scanning technique . 30
D.3 Examples of pinna simulator shape . 30
D.4 Verification of conformance . 31
Bibliography . 32

Figure 1 – Manikin geometrical references . 10
Figure 2 – Coordinate scheme for azimuth and elevation angles . 11
Figure 3 – Illustration of manikin head and torso dimensions . 12
Figure 4 – Illustration of manikin pinna simulator dimensions . 15
Figure A.1 – Example of an anatomically shaped manikin . 26

IEC 60318-7:2017  IEC 2017 – 3 –
Figure B.1 – Example 1 of a geometrically shaped manikin . 27
Figure B.2 – Example 2 of a geometrically shaped manikin . 28
Figure C.1 – Relationship between tolerance interval, corresponding acceptance
interval and the maximum permitted uncertainty of measurement . 29
Figure D.1 – (Embedded 3D PDFs) – Examples of a pinna simulator . 31

Table 1 – Manikin head and torso dimensions . 13
Table 2 – Dimensions of the pinna simulator and the cylindrical ear canal extension of
the manikin . 16
Table 3 – Dimensions of the pinna simulator and the tapered ear canal extension of
the manikin . 16
Table 4 – Free-field frequency response of the manikin for an azimuth angle of 0°
(right ear). 18
Table 5 – Free-field frequency responses of the manikin for azimuth angles of 90°,
180° and 270° (right ear) . 19
Table 6 – Diffuse-field frequency response of the manikin (right ear) . 20
Table 7 – Maximum permitted uncertainty U for type approval measurements . 25
max
– 4 – IEC 60318-7:2017  IEC 2017
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTROACOUSTICS – SIMULATORS OF HUMAN HEAD AND EAR –

Part 7: Head and torso simulator for the measurement of
air-conduction 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.
The main task of IEC technical committees is to prepare International Standards. In
exceptional circumstances, a technical committee may propose the publication of a technical
specification when
• the required support cannot be obtained for the publication of an International Standard,
despite repeated efforts, or
• the subject is still under technical development or where, for any other reason, there is the
future but no immediate possibility of an agreement on an International Standard.
Technical specifications are subject to review within three years of publication to decide
whether they can be transformed into International Standards.
IEC TS 60318-7, which is a Technical Specification, has been prepared by IEC technical
committee 29: Electroacoustics.

IEC 60318-7:2017  IEC 2017 – 5 –
This publication contains attached files in the form of 3D PDF files. These files are intended to
be used as a complement and do not form an integral part of the publication.
This second edition cancels and replaces the first edition published in 2011. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) the document is based on the designs of three different commonly used types of manikins;
b) the cross sections of the head and torso and pinna simulators of the previous edition are
replaced by maximum and minimum values of their geometric dimensions;
c) the diffuse field frequency response of the manikin is added;
d) the usable frequency range is extended to 100 Hz to 16 000 Hz;
e) in addition to the cylindrical ear canal extension a tapered ear canal extension is added;
f) design examples of one anatomically shaped manikin and of two different geometrically
shaped manikins are given in the annexes;
g) the relationship between tolerance interval, corresponding acceptance interval and the
maximum permitted uncertainty of measurement are given in an annex;
h) 3D representations of three different types of pinna simulators are given in an annex.
The text of this technical specification is based on the following documents:
Enquiry draft Report on voting
29/907/DTS 29/921A/RVDTS
Full information on the voting for the approval of this technical specification 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 of IEC 60318 series, published under the general title Electroacoustics –
Simulators of human head and ear, 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.
A bilingual version of this publication may be issued at a later date.

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.
– 6 – IEC 60318-7:2017  IEC 2017
ELECTROACOUSTICS – SIMULATORS OF HUMAN HEAD AND EAR –

Part 7: Head and torso simulator for the measurement of
air-conduction hearing aids
1 Scope
This document, which is a Technical Specification, describes a head and torso simulator, or
manikin, intended for the measurement of air-conduction hearing aids in the frequency range
from 100 Hz to 16 000 Hz.
The manikin described in this document is intended for airborne acoustic measurements only.
It is not suitable for measurements which depend upon vibration transmission paths such as
bone conduction, or for measurements requiring the simulation of bone or tissue.
This document specifies the manikin in terms of both its geometrical dimensions and its
acoustical properties. Only manikins compliant with both sets of specifications are in
conformance with this document.
WARNING – It is acknowledged that devices conforming to this document are used as the
basis for applications extending beyond this scope, for example the measurement of sound
sources close to the ear or of hearing protection devices. In such cases, it is recommended
that any necessary design variations are documented, and that a statistical analysis of the
measurement data is carried out to determine the level of repeatability that can be achieved.
It will also be necessary to assess the relevance of the measurements made with the head
and torso simulator to the application in question.
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 60118-8, Electroacoustics – Hearing aids – Part 8: Methods of measurement of
performance characteristics of hearing aids under simulated in situ working conditions
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 61260-1, Electroacoustics – Octave-band and fractional-octave-band filters – Part 1:
Specifications
ISO/IEC Guide 98-4, Uncertainty of measurement – Role of measurement uncertainty in
conformity assessment
ISO 3:1973, Preferred numbers – Series of preferred numbers

IEC 60318-7:2017  IEC 2017 – 7 –
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
manikin
head and torso simulator
simulator of a median adult human head and part of the torso extending in total from the top
of the head to the waist and designed to simulate the sound pick-up characteristics and
acoustic diffraction
Note 1 to entry The head and torso simulator includes two pinna simulators, and at least one occluded-ear
simulator.
3.2
manikin type
designation of the manikin as either anatomical or geometrical in shape
3.3
pinna simulator
device which has the approximate shape and dimensions of a median adult human pinna
3.4
ear simulator
device for measuring the acoustic output of sound sources where the sound pressure is
measured by a calibrated microphone coupled to the source so that the overall acoustic
impedance of the device approximates that of the normal human ear at a given location and in
a given frequency band
Note 1 to entry In this document, an ear simulator comprises an ear canal extension and an occluded-ear
simulator (see 4.2.4).
3.5
occluded-ear simulator
ear simulator which approximates the acoustic transfer impedance of the inner part of the ear
canal, from the tip of an ear insert to the eardrum
Note 1 to entry An occluded-ear simulator is standardised in IEC 60318-4.
3.6
ear canal extension
device that provides a connection between the occluded-ear simulator and the aperture of the
device simulating the concha
3.7
reference plane of the occluded-ear simulator
plane perpendicular to the axis of the cavity of the simulator, chosen to pass through the
position normally occupied by the tip of an ear mould in a human ear canal
3.8
reference point of the manikin
point bisecting the line joining the right and left ear canal entrance points (EEP, see 3.17)

– 8 – IEC 60318-7:2017  IEC 2017
3.9
plane of symmetry of the manikin
plane passing through the reference point of the manikin that divides the left and right
portions of the manikin into symmetrical halves, within the allowed tolerances, where left and
right is interpreted as for the human torso
Note 1 to entry See Figure 1.
3.10
axis of rotation of the manikin
straight line about which the manikin can be rotated, passing through the reference point of
the manikin, lying in the plane of symmetry of the manikin, and having a direction that would
be vertical if the manikin were mounted in a position corresponding to that of a standing
person
Note 1 to entry See Figure 1.
3.11
reference plane of the manikin
plane perpendicular to the axis of rotation that contains the reference point of the manikin
Note 1 to entry See Figure 1.
3.12
test point
reproducible position in the test space at which the sound pressure level is measured with the
manikin absent and at which the reference point of the manikin is to be located for test
purposes
Note 1 to entry See Figure 2.
3.13
test axis
line joining the test point and the centre of the sound source
Note 1 to entry See Figure 2.
3.14
test plane
plane perpendicular to the test axis and containing the test point
3.15
azimuth angle of sound incidence
angle between the plane of symmetry of the manikin and the plane defined by the axis of
rotation of the manikin and the test axis
Note 1 to entry When the manikin faces the sound source, the azimuth angle of sound incidence is defined as 0°.
When the right ear of the manikin faces the sound source, the angle is defined as +90°. When the left ear of the
manikin faces the sound source, the angle is defined as +270°.
Note 2 to entry See Figure 2.
3.16
elevation angle of sound incidence
angle between the reference plane of the manikin and the test axis
Note 1 to entry When the vertex points towards the sound source the elevation angle is defined as +90°. When
the test axis lies in the reference plane of the manikin, the elevation angle is defined as 0°.
Note 2 to entry See Figure 2.
IEC 60318-7:2017  IEC 2017 – 9 –
3.17
ear canal entrance point
EEP
point located at the centre of the manikin ear canal at the junction between concha and ear
canal extension
3.18
transverse plane of the manikin
plane perpendicular to the plane of symmetry of the manikin and containing the axis of
rotation
3.19
reference position of the manikin
position of the manikin in the test space where the reference point of the manikin coincides
with the test point, and the azimuth and elevation angles are both equal to zero
3.20
manikin free-field frequency response
difference, as a function of frequency, between the sound pressure level at the ear simulator
microphone with the reference point of the manikin at the test point within a free-field
measurement environment and the sound pressure level at the test point with the manikin
absent
3.21
manikin diffuse-field frequency response
difference, as a function of frequency, between the sound pressure level at the ear simulator
microphone with the reference point of the manikin at the test point within a diffuse-field
measurement environment and the sound pressure level at the test point with the manikin
absent
– 10 – IEC 60318-7:2017  IEC 2017
Vertex Vertex
Reference point
Reference plane
90°
90°
Axis of rotation
Plane of symmetry
Reference point (and top
view of axis of rotation).
It bisects the line joining
the centres of the openings
of the ear simulator canals.
90°
IEC
NOTE The reference point of the manikin is situated within the head.
Figure 1 – Manikin geometrical references

IEC 60318-7:2017  IEC 2017 – 11 –
Test axis
Reference point
and test point
Elevation angle of sound incidence
α
Range: –90° to +90°
Reference plane
Azimuth angle of sound incidence
Range: 0° to +360°
θ
Test axis
Reference point
Sound source
and test point
IEC
Figure 2 – Coordinate scheme for azimuth and elevation angles
4 Construction
4.1 General
The simulator consists of a head mounted on a torso that extends to the waist. The head is
equipped with simulated pinnae and one or two occluded-ear simulators formed of cavities
having acoustic impedance terminations corresponding to that of a median human adult, and
microphones located at positions corresponding to the eardrums. It has been designed to
provide acoustic diffraction similar to that encountered around the median human head and
torso. Measurement results obtained with a manikin can differ substantially from similar
measurements made on an individual person, due to anatomical variations. Measurement
results for a given hearing aid obtained with different models of manikin conforming to this
document can also differ, depending on the type and the method of fitting the hearing aid. The
same holds for measurement results obtained with the same manikin model but with different
models of pinna simulators. Above 10 kHz, an occluded-ear simulator conforming to
IEC 60318-4 does not simulate the acoustic impedance of the human ear and can only be
used as an acoustic coupler in this frequency range.
The realization of the manikin conforming to this document can be either anatomically shaped
(see Annex A) or geometrically shaped (see Annex B) and can have different anatomically
shaped pinna simulators. The realization of the ear canal entrance, together with the
additional ear canal extension can be either cylindrical or tapered in shape. This enables the

– 12 – IEC 60318-7:2017  IEC 2017
measurements of all types of hearing aids, for example behind-the-ear (BTE) and in-the-ear
(ITE) designs.
NOTE Nevertheless, some specific ITE hearing aid models might not be compatible.
This document covers both the geometrical dimensions of the manikin’s head, torso, pinnae
and ear canals and the manikin’s acoustical characteristics. As a minimum, the manikin shall
be specified with cylindrical ear canal extensions, and comply with the appropriate acoustical
characteristics. Optionally, tapered ear canal extensions may also be specified. The model
and type of the manikin used (see 3.2) and the model of the pinna simulator used shall be
stated when giving results of hearing aid measurements made with the manikin.
4.2 Geometrical dimensions of the manikin
4.2.1 Head and torso
The geometrical dimensions of the head and the torso are illustrated in Figure 3, and listed in
Table 1. The realization of the head (excluding the pinnae) and of the torso can be either
anatomically shaped or geometrically shaped. Anatomically shaped manikins are not
necessarily completely symmetrical and may be described as "quasi-symmetrical", when
staying within the allowable differences from the completely symmetrical manikin. Both
anatomically and geometrically shaped manikins shall conform to the specified ranges of
geometrical dimensions and acoustical characteristics specified in this document.
The acceptance interval of the quasi-symmetrical left and right portion of the manikin shall be
± 2 mm for the head and ± 3 mm for the torso with respect to the plane of symmetry.
NOTE For measurements that include both head and torso dimensions, for example EEP to shoulder, the
acceptance interval sums up to ± 5 mm.
Head length
Head breadth
EEP to occipital wall
EEP to vertex
Chin-to-vertex
Neck diameter
EEP to EEP
Shoulder location
Chest breadth
Shoulder
Shoulder position
Shoulder breadth depth
Chest depth
IEC
NOTE For position of ear canal entrance point (EEP), see Figure 4.
Figure 3 – Illustration of manikin head and torso dimensions
EEP to shoulder
Manikin height
EEP to shoulder
IEC 60318-7:2017  IEC 2017 – 13 –
Table 1 – Manikin head and torso dimensions
Linear dimension of Nominal Minimum Maximum 1
Average human data [19]
mm mm mm
mm
Head breadth  151 148 153 151
Head length 195 190 204 188
EEP to vertex 130 128 135 130
EEP to EEP distance 132 130 134 132
EEP to occipital wall 95 93 99 95
Chin-to-vertex length 220 217 225 222
c
EEP to shoulder 175 169 181 176
Neck diameter 113 111 115 112
Shoulder breadth 432 399 456 427
Chest breadth 282 280 284 291
Chest depth 219 180 241 –
d
Shoulder depth 110 108 161 –
b, e
Shoulder location 6 –4 20 –
a, f
Shoulder position 78 76 80 –
Manikin height – 600 –
NOTE To be independent of the type of pinna simulator used, this document uses the ear canal entrance point
(EEP) rather than the tragion as a reference point. The differences between both sets of values are chosen in
conformity with [8] to be 5 mm for EEP to vertex, –11 mm for left EEP to right EEP, –3 mm for EEP to occipital wall
and –5 mm for EEP to shoulder.
a For anatomically shaped manikin only.
b For geometrically shaped manikin only.
c Measured from the shoulder surface, 175 mm sideways from the plane of symmetry, to the reference plane of
the manikin.
d Measured between front and back shoulder points, 175 mm sideward from the plane of symmetry of the
manikin.
e Measured from the point of the shoulder section, 175 mm sideward from the plane of symmetry, to the
transverse plane of the manikin (positive behind transverse plane).
f Measured between front shoulder point, 175 mm sideward from the plane of symmetry of the manikin to the

front-most point on the torso.

4.2.2 Pinna simulators for hearing aid measurements
The right and left pinna simulators shall be anatomically shaped.
For each type of manikin, only one pair of pinna simulators with cylindrical ear canal
extensions and optionally only one pair of pinna simulators with the tapered ear canal
extensions shall be specified. Their principal dimensions and orientation are illustrated in
Figure 4, and listed in Table 2 and Table 3.
The acceptance intervals of the quasi-symmetrical left and right pinna simulator of the
manikin shall be ±2 mm.
NOTE In addition to the pinna simulators described in this document, there are many other models of pinna
simulator on the market, for instance a small one used for the measurement of earphones (see IEC 60268-7).
However, these pinna simulators are not intended for hearing aid measurements.
___________
Numbers in square brackets refer to the Bibliography.

– 14 – IEC 60318-7:2017  IEC 2017
4.2.3 Ear canal extension
Only one cylindrical, and optionally, one tapered ear canal extension shall be used. The
cylindrical ear canal extension shall have a nominal diameter of 7,50 mm. It is mainly
intended for the measurement of behind-the-ear and full-concha in-the-ear types of hearing
aids. If a tapered ear canal extension is specified, it shall have a nominal diameter of
7,50 mm where it couples to the occluded-ear simulator and a larger diameter where it
couples to the bottom of the concha of the pinna simulator (see Table 3). Tapered ear canal
extensions are mainly intended for the measurement of in-the-ear and completely-in-the-canal
types of hearing aids.
IEC 60318-7:2017  IEC 2017 – 15 –
Side view
Vertical tilt
Ear breadth
Ear length
above EEP
Ear length
Concha
length Concha
length
below
EEP
Concha breadth,
EEP to anti-helix
Concha breadth,
Tragion to anti-helix
IEC
Key
1 anti-helix 4 EEP
2 helix 5 tragion
3 concha 6 crus of helix
Figure 4 a) – Pinna simulator
Cross-section
Protrusion angle
Ear canal
Concha
extension
depth
IEC
Figure 4 b) – Ear canal extension cylindrical
Cross-section
Protrusion angle
Ear canal
Concha
extension
depth
tapered
IEC
Figure 4 c) – Ear canal extension tapered
Figure 4 – Illustration of manikin pinna simulator dimensions
Protrusion
Protrusion
– 16 – IEC 60318-7:2017  IEC 2017
Table 2 – Dimensions of the pinna simulator and the cylindrical ear
canal extension of the manikin
Linear dimension of Nominal Minimum Maximum
mm or degrees mm or degrees mm or degrees
Ear length 65 64 67
Ear length above EEP 35 33 38
Ear breadth 37 36 38
Ear protrusion 20 18 24
Ear protrusion angle 160° 159,5° 160,5°
Vertical tilt front view 9° 7,5° 10,5°
Vertical tilt side view 6° 5,5° 6,5°
Concha length 24 23 26
Concha length below EEP 10 8 11
Concha breadth, tragion to anti-helix 23 22 24
Concha breadth, EEP to anti-helix 17 14 20
Concha depth 13 11 16
Diameter of ear canal extension 7,50 7,40 7,60
Length of ear canal extension 10 9 11

Table 3 – Dimensions of the pinna simulator and the tapered ear canal extension
of the manikin
Linear dimension of Nominal Minimum Maximum
mm or degrees mm or degrees mm or degrees
Ear length 66 65 67
Ear length above EEP 36 35 37
Ear breadth 37 36 38
Ear protrusion 23 19 24
Ear protrusion angle 160° 159,5° 160,5°
Vertical tilt front view 10° 8° 10,5°
Vertical tilt side view 6° 5,5° 6,5°
Concha length 28 24 29
Concha length below EEP 10 9 11
Concha breadth, tragion to anti-helix 23 22 24
Concha breadth, EEP to anti-helix 23 19 24
Concha depth 15 12 16
Diameter of ear canal extension at the 7,50 7,40 7,60
reference plane of the occluded-ear
simulator
Diameter of ear canal extension at the 10 9,5 10,5
pinna simulator
Length of ear canal extension 8,8 7,8 10

4.2.4 Ear simulator
The ear simulator shall comprise an occluded-ear simulator, for example as described in
IEC 60318-4, and an ear canal extension (see 3.4).

IEC 60318-7:2017  IEC 2017 – 17 –
If occluded-ear simulators differing in detail from that specified in IEC 60318-4 are used, their
characteristics should be stated when giving results of measurements of hearing aids made
with the manikin.
4.2.5 Materials
The manikin shall have a non-porous surface, with an acoustic impedance which is high
compared to that of air, and be of a material which ensures dimensional stability.
The pinna simulators shall be made from a high-quality elastomer. The shore-OO hardness
[18] shall be in the range from 30° to 60°. The time interval for which the mechanical
characteristics of the pinna simulators are expected to remain compliant with this document
shall be indicated by means of an expiration date.
Measurement results on hearing aids obtained with the same manikin fitted with different
pinna simulator models can differ by varying degrees depending on the type of hearing aid
under test and the way it is fitted. The model, or similar identification, of the pinna simulators
together with their shore-OO hardness should be stated when giving results of hearing aid
measurements made with the manikin.
4.3 Acoustical characteristics of the manikin
4.3.1 Free-field frequency response
Table 4 and Table 5 give the free-field frequency responses of the manikin (right ear)
equipped with cylindrically shaped ear canal extensions. Values are stated for 0° elevation
angle and azimuth angles of 0° (frontal incidence), 90°, 180° and 270°. The values also apply
for the corresponding symmetrical azimuth angles for the left pinna.
NOTE 1 Difficulties can be experienced when measuring the manikin frequency response at the azimuth angle
270° for 6,3 kHz and higher frequencies. This is due to a combination of reflections from the boundaries of the test
enclosure, and the head shadow effect. Hence, these values have been omitted in Table 5.
The nominal free-field frequency responses were obtained from a power average of the
measured free-field frequency responses of the three manikins in Annex A and Annex B,
extracted from [16]. The free field-frequency response is given in one-twelfth-octave intervals
centred at the nominal one-third-octave band centre frequencies.
NOTE 2 The nominal one-third-octave band centre frequencies used as test frequencies in Table 3 and Table 4
correspond to the ISO 3 R 10 preferred number series.

– 18 – IEC 60318-7:2017  IEC 2017
Table 4 – Free-field frequency response of the manikin
for an azimuth angle of 0° (right ear)
One-third-octave band centre frequency Free-field frequency response Acceptance interval
Hz dB dB
Azimuth angle
0°
100 0,0 +1,5 –1,5
125 0,0 +1,5 –1,5
160 0,0 +1,5 –1,5
200 0,0 +1,5 –1,5
250 0,0 +1,5 –1,5
315 1,0 +1,5 –1,5
400 2,0 +1,5 –1,5
500 2,5 +2,0 –1,5
630 3,0 +1,5 –1,5
800 4,0 +1,5 –1,5
1 000 4,0 +2,0 –2,5
1 250 3,0 +2,0 –3,5
1 600 5,0 +1,5 –2,0
2 000 12,0 +2,0 –2,5
2 500 16,5 +3,0 –3,0
3 150 17,5 +2,0 –2,5
4 000 14,0 +2,0 –3,0
5 000 11,5 +2,5 –3,0
6 300 7,0 +2,0 –2,0
8 000 2,0 +3,5 –5,5
10 000 2,0 +4,0 –4,5
12 500 9,0 +4,0 –4,5
16 000 3,0 +4,0 –6,0
NOTE 1 The free field-frequency response is given in one-twelfth-octave intervals centred at the nominal one-
third-octave band centre frequencies.
NOTE 2 The values in Table 4 are valid only for pinna simulators for hearing aid measurements by means of
cylindrical ear canal extensions according to Table 2.

IEC 60318-7:2017  IEC 2017 – 19 –
Table 5 – Free-field frequency responses
of the manikin for azimuth angles of 90°, 180° and 270° (right ear)
One-third-octave band centre Free-field frequency response Acceptance interval
frequency
Hz dB dB
Azimuth angle
90° 180° 270°
100 0,5 0,0 –0,5 +1,5 –1,5
125 0,5 0,0 –0,5 +1,5 –1,5
160 1,0 –0,5 –1,0 +1,5 –1,5
200 1,5 0,0 –1,0 +1,5 –2,0
250 2,5 0,0 –0,5 +1,5 –1,5
315 3,5 0,0 0,0 +1,5 –1,5
400 4,5 0,5 0,5 +1,5 –1,5
500 5,5 1,0 1,5 +2,0 –1,5
630 7,0 2,0 1,5 +1,5 –2,0
800 8,0 4,0 2,0 +1,5
–2,0
1 000 7,5 4,0 2,5 +1,5 –2,0
1 250 9,5 5,5 3,5 +2,5 –2,5
1 600 9,5 5,5 5,0 +2,0 –2,0
2 000 11,0 9,5 7,0 +2,5 –4,0
2 500 16,5 14,0 10,0 +2,5 –2,5
3 150 17,0 13,5 9,0 +3,0 –2,0
4 000 13,5 10,5 3,5 +5,0 –3,0
5 000 17,0 6,0 –3,5 +7,0 –8,0
6 300 17,0 2,0 – +2,5 –5,0
8 000 16,5 3,5 – +5,0 –10,5
10 000 10,5 –1,5 – +6,0 –10,5
12 500 11,5 –0,5 – +6,0 –8,5
16 000 3,5 –4,0 – +6,0 –11,0
NOTE 1 The free field-frequency response is given in one-twelfth-octave intervals centred at the nominal one-
third-octave band centre frequencies.
NOTE 2 The values in Table 5 are valid only for pinna simulators for hearing aid measurements by means of
cylindrical ear canal extensions according to Table 2.
NOTE 3 Free-field responses for 0° azimuth angle are given in Table 4.

4.3.2 Diffuse-field frequency response
Table 6 gives the diffuse-field frequency response of the manikin (right ear) equipped with
cylindrically shaped ear canal extensions.
The nominal diffuse-field frequency responses were obtained from a power average of the
diffuse-field frequency responses of the three manikins in Annex A and Annex B, extracted
from [16]. The diffuse-field frequency response is given in one-third-octave frequency
intervals.
– 20 – IEC 60318-7:2017  IEC 2017
Table 6 – Diffuse-field frequency response of the manikin (right ear)
One-third-octave band centre Diffuse-field frequency response Acceptance interval
frequency
Hz dB dB
100 -0,5 +1,5 -1,5
125 0,0 +1,5 -1,5
160 0,0 +1,5 -1,5
200 0,5 +1,5 -1,5
250 0,0 +1,5 -1,5
315 0,5 +1,5 -1,5
400 1,5 +1,5 -1,5
500 2,0 +1,5 -1,5
630 3,5 +1,5 -1,5
800 3,5 +1,5 -1,5
1 000 4,0 +1,5 -2,0
1 250 5,0 +1,5 -1,5
1 600 7,0 +1,5 -2,0
2 000 10,5 +2,0 -2,0
2 500 14,0 +2,0 -2,0
3 150 14,5 +2,5 -2,0
4 000 12,5 +2,0 -2,0
5 000 9,5 +2,0 -2,0
6 300 8,0 +2,5 -2,0
8 000 8,0 +2,5 -2,5
10 000 5,0 +3,5 -2,5
12 500 2,5 +4,5 -2,5
16 000 0,0 +6,5 -4,0
NOTE The values in Table 6 are valid only for pinna simulators for hearing aid measurements by means of
cylindrical ear canal extensions according to Table 2.

4.3.3 Acceptance intervals
Acceptance intervals on the manikin free-field and diffuse-field frequency responses are
stated in Table 4, Table 5 and Table 6. The values include the acceptance interval in the
calibration of the occluded-ear simulator, but not the free-field or diffuse-field sensitivity of the
microphone. They are rounded to the nearest 0,5 dB increment.
4.3.4 Openings
Any openings for access to the interior of the manikin other than the ears shall not affect the
responses of the manikin as specified in 4.3.1 and 4.3.2.

IEC 60318-7:2017  IEC 2017 – 21 –
5 Calibration
5.1 Reference environmental conditions
The reference environmental conditions are the following.
Reference ambient pressure: . 101,325 kPa
Reference temperature: . 23 °C
Reference relative humidity:. 50 %
5.2 Calibration method
5.2.1 General
When determining the acoustical characteristics of the manikin, no wig shall be used with the
head and no clothing shall be used with the head or torso. If the head can be inclined, the
upright position shall be used. If the length of the neck can be adjusted, the nominal value of
"EEP to shoulder" from Table 1 shall be used.
5.2.2 Test signal, test space and measurement equipment
5.2.2.1 Free-field testing
The manikin free-field frequency response shall be measured in one-twelfth-octave frequency
intervals at centre frequencies as given in the ISO 3 R 10 preferred frequency series.
Any stimulus providing adequate energy at all frequencies of interest can be used as test
signal.
NOTE 1 The test signal used in [16] was a 16 seconds long exponential swept sine from 20 Hz to 25,6 kHz. Its
advantage is a considerably improved signal-to-noise ratio. The one-twelfth-octave-band frequency response data
were in turn calculated from the swept-sine data using the methodology given in [20].
For the manikin free-field frequency response, the test space and sound source shall together
pro
...