SIST EN ISO 7029:2017

SLOVENSKI STANDARD
SIST EN ISO 7029:2017
01-maj-2017
1DGRPHãþD
SIST EN ISO 7029:2001
$NXVWLND6WDWLVWLþQDSRUD]GHOLWHYSUDJDVOLãQRVWLYRGYLVQRVWLRGVWDURVWLLQVSROD
,62
Acoustics - Statistical distribution of hearing thresholds related to age and gender (ISO
7029:2017)
Acoustique - Distribution statistique des seuils d'audition en fonction de l'âge et du sexe
(ISO 7029:2017)
Ta slovenski standard je istoveten z: EN ISO 7029:2017
ICS:
13.140 Vpliv hrupa na ljudi Noise with respect to human
beings
17.140.99 Drugi standardi v zvezi z Other standards related to
akustiko acoustics
SIST EN ISO 7029:2017 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 7029:2017

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SIST EN ISO 7029:2017


EN ISO 7029
EUROPEAN STANDARD

NORME EUROPÉENNE

January 2017
EUROPÄISCHE NORM
ICS 13.140 Supersedes EN ISO 7029:2000
English Version

Acoustics - Statistical distribution of hearing thresholds
related to age and gender (ISO 7029:2017)
Acoustique - Distribution statistique des seuils
d'audition en fonction de l'âge et du sexe (ISO
7029:2017)
This European Standard was approved by CEN on 14 January 2017.

CEN 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 CEN
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 CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and United Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2017 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 7029:2017 E
worldwide for CEN national Members.

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SIST EN ISO 7029:2017
EN ISO 7029:2017 (E)
Contents Page
European foreword . 3
2

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SIST EN ISO 7029:2017
EN ISO 7029:2017 (E)
European foreword
This document (EN ISO 7029:2017) has been prepared by Technical Committee ISO/TC 43 “Acoustics”
in collaboration with Technical Committee CEN/TC 211 “Acoustics” the secretariat of which is held by
DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by July 2017, and conflicting national standards shall be
withdrawn at the latest by July 2017.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent
rights.
This document supersedes EN ISO 7029:2000.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 7029:2017 has been approved by CEN as EN ISO 7029:2017 without any modification.


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SIST EN ISO 7029:2017

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SIST EN ISO 7029:2017
INTERNATIONAL ISO
STANDARD 7029
Third edition
2017-01
Acoustics — Statistical distribution
of hearing thresholds related to age
and gender
Acoustique — Distribution statistique des seuils d’audition en
fonction de l’âge et du sexe
Reference number
ISO 7029:2017(E)
©
ISO 2017

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SIST EN ISO 7029:2017
ISO 7029:2017(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2017, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
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Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2017 – All rights reserved

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SIST EN ISO 7029:2017
ISO 7029:2017(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 2
3 Terms and definitions . 2
4 Specification . 2
4.1 General . 2
4.2 Median . 3
4.3 Distribution around the median . 3
4.4 Application of data . 5
Annex A (informative) Selected values of the Gaussian distribution . 7
Annex B (informative) Numerical example to illustrate the procedure . 8
Annex C (informative) Median values of expected hearing threshold deviations .9
Annex D (informative) Selected values of the statistical distribution of hearing
threshold deviations.10
Annex E (informative) Expected median thresholds at audiometric frequencies from
9 000 Hz to 12 500 Hz .13
Annex F (informative) Notes on the derivation of descriptive statistics of hearing thresholds .15
Annex G (informative) Dispersion of source data around the expected median of
hearing thresholds .20
Bibliography .21
© ISO 2017 – All rights reserved iii

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SIST EN ISO 7029:2017
ISO 7029:2017(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment,
as well as information about ISO’s adherence to the World Trade Organization (WTO) principles in the
Technical Barriers to Trade (TBT) see the following URL: www . i so .org/ iso/ foreword .html.
The committee responsible for this document is ISO/TC 43, Acoustics.
This third edition cancels and replaces the second edition (ISO 7029:2000), which has been technically
revised with the following changes:
— new data has been adopted, as explained in the introduction;
— estimation accuracy of expected medians and statistical distributions of hearing thresholds were
generally improved by modifying the formulae used;
— the age range for which the expected medians and statistical distributions of hearing thresholds are
calculable was extended to the age of 80 years at audiometric frequencies of 2 000 Hz and below; it
was up to 70 years for all frequencies in the previous editions.
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SIST EN ISO 7029:2017
ISO 7029:2017(E)

Introduction
The sensitivity of human hearing is well known to decrease with age and the impairment of hearing
develops more rapidly for sound at high frequencies than at low frequencies. Moreover, the magnitude
of this effect varies considerably among individuals.
When testing the hearing of persons markedly over 18 years of age, part of any observed hearing loss
will probably be associated with age. It is important to be aware of this when estimating the amount of
hearing loss attributable to other causes under investigation.
It should be noted that a decrease in hearing ability may not necessarily be caused by ageing itself, but
by many injurious influences during lifetime, which are not known in detail.
This document is based on a thorough examination of literature data on the differences between groups
having different ages for populations of otologically normal persons as defined herein. Distinction is
made between males and females since the difference is found to be of significance in the case of older
age groups. The data have been derived from investigations using pure tones transmitted to the ear
from an earphone, but no evidence is known that disqualifies their use for noise band stimuli.
This document is a revision of the second edition (ISO 7029:2000). The expected medians and statistical
distributions of hearing thresholds were re-estimated using audiometric data published after the
establishment of the first edition (ISO 7029:1984). All the data on which the second edition had been
based were discarded. Thus, this third edition describes the hearing sensitivity profile of people in
recent years.
Hearing thresholds presented in this document are generally lower at high frequencies than those in
the previous editions of this document. The 4 kHz dip observed in males has become negligibly small.
The source data of the previous editions might not have been screened rigorously in terms of hearing
abnormalities. Problems related to instrumentation might also have affected measurement data.
The expected median hearing thresholds at the frequencies from 9 000 Hz to 12 500 Hz are presented
for information. Audiometry at those frequencies is executable using an extended high-frequency
audiometer.
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SIST EN ISO 7029:2017
INTERNATIONAL STANDARD ISO 7029:2017(E)
Acoustics — Statistical distribution of hearing thresholds
related to age and gender
1 Scope
This document provides descriptive statistics of the hearing threshold deviation for populations
of otologically normal persons of various ages under monaural earphone listening conditions. It
specifies the following, for populations within the age limits from 18 years to 80 years for the range of
audiometric frequencies from 125 Hz to 8 000 Hz:
a) the expected median value of hearing thresholds given relative to the median hearing threshold at
the age of 18 years;
b) the expected statistical distribution above and below the median value.
For the frequencies from 3 000 Hz to 8 000 Hz, the median and statistical distribution for populations
above 70 years are presented for information only.
This document also provides for information the expected median values at audiometric frequencies
from 9 000 Hz to 12 500 Hz within the age limits from 22 years to 80 years.
The data are applicable for estimating the amount of hearing loss caused by a specific agent in a
population. Such a comparison is valid if the population under study consists of persons who are
otologically normal except for the effect of the specific agent. Noise exposure is an example of a specific
agent and for this application, selected data from this document are referred to as “database A” in
ISO 1999.
NOTE 1 ISO 1999:2013, Database A is based on a previous edition of ISO 7029.
The data may also be used to assess an individual’s hearing in relation to the distribution of hearing
thresholds which is normal for the person’s age group. However, it is not possible to determine for
an individual precisely which part of an observed hearing loss is attributable to an accumulation of
detrimental effects on the hearing which increase with age, and which part has been caused by other
factors such as noise.
The hearing threshold deviation as defined herein and the hearing threshold level as defined in other
International Standards (ISO 389-1, ISO 389-2, ISO 389-5, ISO 389-8, ISO 8253-1, ISO 8253-2, IEC 60645-
1) express the hearing threshold of an individual or an individual ear, respectively, relative to
— the expected median hearing threshold of 18-year-old age group of the same gender, or
— a reference zero level specified in various parts of ISO 389.
To the extent that the reference zero level represents the median of the 18-year-old population, the
values of the two terms will be the same.
NOTE 2 The values of these two are not always the same for some reasons. One reason is that the reference
zero level has been determined based on the hearing threshold levels of persons older than 18 years, including
those aged up to 25 years or to 30 years, who have slightly worse hearing sensitivity on average.
NOTE 3 ISO 28961 specifies the expected statistical distribution of hearing thresholds, expressed in sound
pressure level in decibels, for populations of otologically normal persons of the age from 18 years to 25 years
under binaural, free-field listening conditions. It enables the calculation not only at audiometric frequencies, but
also for other frequencies at one-third-octave intervals from 20 Hz to 16 000 Hz.
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SIST EN ISO 7029:2017
ISO 7029:2017(E)

2 Normative references
There are no normative references in this document.
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 https:// www .iso .org/ obp/
3.1
otologically normal person
person in a normal state of health who is free from all signs or symptoms of ear disease and from
obstructing wax in the ear canal and who has no history of undue exposure to noise, exposure to
potentially ototoxic substances or familial hearing loss
[SOURCE: ISO 8253-1:2010, 3.7, modified — The term “ototoxic drugs” has been changed to “ototoxic
substances”.]
3.2
hearing threshold deviation
ΔH
threshold of hearing of an individual minus the median threshold of hearing of a population of 18-year-
old otologically normal persons (3.1) of the same gender
Note 1 to entry: The term threshold of hearing is defined in ISO 389-1:1998, 3.4.
4 Specification
4.1 General
The statistical distribution of hearing threshold deviations for otologically normal persons of a specific
age Y and a specific gender is given in terms of the median value (see 4.2) and the distribution around
the median (see 4.3).
The range of Y is from 18 years to 80 years for audiometric frequencies from 125 Hz to 8 000 Hz. For the
frequencies from 3 000 Hz to 8 000 Hz, the Y value above 70 years is given for information purposes only.
NOTE The statistical distribution estimation for the age above 70 years at 3 000 Hz and above is subject to
a large uncertainty because the hearing threshold level from many subjects is not obtainable (“scales out”) at
those frequencies.
Annex E presents expected median thresholds at audiometric frequencies from 9 000 Hz to 12 500 Hz.
Annex F discusses the derivation of the descriptive statistics of hearing thresholds.
Annex G shows root-mean-square error (RMSE) values and estimating the uncertainty of the
statistical values.
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SIST EN ISO 7029:2017
ISO 7029:2017(E)

4.2 Median
The median value ΔH , in decibels, at audiometric frequencies from 125 Hz to 8 000 Hz is given by
md,Y
Formula (1):
β
md
DHY=−α � 18 (1)
()
md,mY d
where
α and β are dimensionless quantities as given in Table 1;
md md
Y is the age in years.
The age of 18 years is the lower limit of the Y range for which Formula (1) is valid.
Table 1 — Values of α and β in Formula (1)
md md
Frequency α β
md md
Hz Males Females Males Females
–6 –4
125 2,50 × 10 6,16 × 10 3,841 2,451
–4 –4
250 1,39 × 10 3,98 × 10 2,832 2,568
–4 –4
500 4,59 × 10 2,61 × 10 2,537 2,708
–4 –4
750 5,70 × 10 2,25 × 10 2,512 2,775
–4 –4
1 000 7,02 × 10 2,21 × 10 2,494 2,805
–3 –4
1 500 1,09 × 10 2,53 × 10 2,446 2,813
–3 –4
2 000 1,56 × 10 3,12 × 10 2,404 2,792
–3 –4
3 000 2,54 × 10 4,88 × 10 2,350 2,728
–3 –4
4 000 3,40 × 10 7,37 × 10 2,325 2,660
–3 –3
6 000 4,53 × 10 1,47 × 10 2,315 2,539
–3 –3
8 000 5,06 × 10 2,53 × 10 2,328 2,439
4.3 Distribution around the median
The distribution around the median shall be approximated by the upper and lower halves, respectively,
of two Gaussian distributions, each with their standard deviation s and s , in decibels, given by
u l
Formulae (2) and (3):
2 3 44 5
s =γγ++YY−18 γγ−18 ++YY−18 γ −18 + γ Y −18 (2)
() () () () ()
u0,su1,su2,su 3,su 4,su 5,su
2 3 44 5
s =γγ++YY−18 γγ−18 ++YY−18 γ −18 + γ Y −18 (3)
() () () () ()
l0,sl1,sl2,sl 3,sl 4,sl 5,sl
The values of coefficients γ and γ (n = 0, 1, 2, ., 5) are given in Tables 2 and 3 for males and in
n,su n,sl
Tables 4 and 5 for females. The age of 18 years is the lower limit of the Y range for which Formulae (2)
and (3) are valid.
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SIST EN ISO 7029:2017
ISO 7029:2017(E)

Table 2 — Values of γ (n = 0, 1, 2, ., 5) in Formula (2) for males
n,su
Frequency
γ γ γ γ γ γ
0,su 1,su 2,su 3,su 4,su 5,su
Hz
–2 –3 –5 –7
125 4,63 0,645 –8,85 × 10 3,69 × 10 –5,98 × 10 3,39 × 10
–2 –3 –5 –7
250 5,27 0,710 –9,13 × 10 3,64 × 10 –5,74 × 10 3,22 × 10
–2 –3 –5 –7
500 4,98 0,751 –9,20 × 10 3,68 × 10 –5,84 × 10 3,28 × 10
–2 –3 –5 –7
750 4,65 0,733 –8,81 × 10 3,59 × 10 –5,76 × 10 3,24 × 10
–2 –3 –5 –7
1 000 4,42 0,714 –8,54 × 10 3,57 × 10 –5,82 × 10 3,29 × 10
–2 –3 –5 –7
1 500 4,14 0,679 –8,04 × 10 3,52 × 10 –5,89 × 10 3,35 × 10
–2 –3 –5 –7
2 000 4,10 0,632 –7,53 × 10 3,46 × 10 –5,94 × 10 3,40 × 10
–2 –3 –5 –7
3 000 4,29 0,530 –6,28 × 10 3,09 × 10 –5,37 × 10 2,95 × 10
–2 –3 –5 –7
4 000 4,68 0,455 –5,52 × 10 2,95 × 10 –5,30 × 10 2,92 × 10
–2 –3 –5 –7
6 000 5,61 0,363 –4,72 × 10 2,92 × 10 –5,58 × 10 3,12 × 10
–2 –3 –5 –7
8 000 6,62 0,291 –4,16 × 10 2,92 × 10 –5,85 × 10 3,33 × 10
Table 3 — Values of γ (n =0, 1, 2, ., 5) in Formula (3) for males
n,sl
Frequency
γ γ γ γ γ γ
0,sl 1,sl 2,sl 3,sl 4,sl 5,sl
Hz
–2 –3 –5 –7
125 3,34 0,131 –2,02 × 10 1,12 × 10 –2,28 × 10 1,57 × 10
–2 –3 –5 –7
250 3,32 0,230 –2,54 × 10 1,20 × 10 –2,27 × 10 1,46 × 10
–2 –3 –5 –7
500 3,43 0,362 –4,11 × 10 1,87 × 10 –3,44 × 10 2,21 × 10
–2 –3 –5 –7
750 3,60 0,384 –4,43 × 10 1,98 × 10 –3,55 × 10 2,22 × 10
–2 –3 –5 –7
1 000 3,77 0,363 –4,19 × 10 1,82 × 10 –3,14 × 10 1,89 × 10
–2 –3 –5 –7
1 500 3,93 0,365 –4,22 × 10 1,79 × 10 –2,96 × 10 1,70 × 10
–2 –3 –5 –7
2 000 4,01 0,387 –4,47 × 10 1,87 × 10 –3,02 × 10 1,69 × 10
–2 –3 –5 –7
3 000 4,11 0,405 –4,56 × 10 1,86 × 10 –2,83 × 10 1,46 × 10
–2 –3 –5 –7
4 000 4,09 0,439 –4,78 × 10 1,92 × 10 –2,84 × 10 1,40 × 10
–2 –3 –5 –7
6 000 4,01 0,497 –4,97 × 10 1,93 × 10 –2,67 × 10 1,18 × 10
–2 –3 –5 –7
8 000 3,90 0,559 –5,62 × 10 2,40 × 10 –3,92 × 10 2,29 × 10
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SIST EN ISO 7029:2017
ISO 7029:2017(E)

Table 4 — Values of γ (n =0, 1, 2, ., 5) in Formula (2) for females
n,su
Frequency
γ γ γ γ γ γ
0,su 1,su 2,su 3,su 4,su 5,su
Hz
–2 –3 –5 –7
125 5,05 0,400 –4,60 × 10 1,73 × 10 –2,75 × 10 1,71 × 10
–2 –3 –5 –7
250 5,01 0,481 –4,88 × 10 1,80 × 10 –2,81 × 10 1,67 × 10
–2 –3 –5 –7
500 4,68 0,510 –5,16 × 10 1,95 × 10 –3,07 × 10 1,77 × 10
–2 –3 –5 –7
750 4,45 0,511 –5,25 × 10 2,03 × 10 –3,18 × 10 1,81 × 10
–2 –3 –5 –7
1 000 4,34 0,492 –5,15 × 10 2,03 × 10 –3,18 × 10 1,78 × 10
–2 –3 –5 –7
1 500 4,23 0,479 –5,12 × 10 2,07 × 10 –3,26 × 10 1,80 × 10
–2 –3 –5 –7
2 000 4,26 0,456 –4,91 × 10 2,01 × 10 –3,16 × 10 1,70 × 10
–2 –3 –5 –7
3 000 4,36 0,476 –5,15 × 10 2,19 × 10 –3,51 × 10 1,91 × 10
–2 –3 –5 –7
4 000 4,61 0,477 –5,07 × 10 2,19 × 10 –3,51 × 10 1,88 × 10
–2 –3 –5 –7
6 000 5,22 0,483 –4,83 × 10 2,13 × 10 –3,39 × 10 1,74 × 10
–2 –3 –5 –7
8 000 5,84 0,516 –4,89 × 10 2,18 × 10 –3,49 × 10 1,77 × 10
Table 5 — Values of γ (n =0, 1, 2, ., 5) in Formula (3) for females
n,sl
Frequency
γ γ γ γ γ γ
0,sl 1,sl 2,sl 3,sl 4,sl 5,sl
Hz
–3 –5 –7 –8
125 3,64 0,047 2,28 × 10 –6,68 × 10 –8,72 × 10 2,30 × 10
–3 –5 –7 –9
250 3,11 0,226 –7,71 × 10 9,83 × 10 –7,11 × 10 9,02 × 10
–2 –4 –6 –8
500 2,98 0,338 –1,74 × 10 3,53 × 10 –2,78 × 10 1,01 × 10
–2 –4 –6 –8
750 3,03 0,378 –2,24 × 10 5,20 × 10 –4,60 × 10 1,50 × 10
–2 –4 –6 –9
1 000 3,15 0,382 –2,39 × 10 5,62 × 10 –4,60 × 10 9,87 × 10
–2 –4 –6 –8
1 500 3,32 0,387 –2,64 × 10 6,71 × 10 –5,76 × 10 1,07 × 10
–2 –4 –6 –8
2 000 3,47 0,392 –2,84 × 10 7,79 × 10 –7,35 × 10 1,71 × 10
–2 –4 –6 –9
3 000 3,69 0,392 –2,96 × 10 8,44 × 10 –7,55 × 10 8,16 × 10
–2 –4 –5 –8
4 000 3,84 0,402 –3,17 × 10 9,99 × 10 –1,08 × 10 2,99 × 10
–2 –3 –5 –8
6 000 4,04 0,403 –3,15 × 10 1,06 × 10 –1,21 × 10 3,44 × 10
–2 –3 –6 –9
8 000 4,15 0,413 –3,01 × 10 1,00 × 10 –9,97 × 10 8,74 × 10
4.4 Application of data
The hearing threshold deviation ΔH which can be expected to be exceeded by a given fraction Q of an
Q,Y
otologically normal population of given age Y and given gender, is given by Formula (4) or (5):
DDHH= + ks (4)
Q,YYmd,u
DDHH= + ks (5)
Q,Y md,Y l
Formula (4) applies when 0,05 ≤ Q ≤ 0,50, whereas Formula (5) applies when 0,50 ≤ Q ≤ 0,95. Values
of the multiplier k correspond to the Gaussian distribution. For information, these values are given in
Table A.1.
Due to uncertainties in the experimental data on which this document is based, tails of the statistical
distributions are only reliable within the range of 0,05 ≤ Q ≤ 0,95.
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SIST EN ISO 7029:2017
ISO 7029:2017(E)

The values given in Tables 1 to 5 are the outcome of comprehensive statistical analyses. The resolution
provided is for calculation only, and the final results should be rounded to the nearest integer of a
decibel.
An example of a calculation is given in Annex B. Calculated values for a range of parameters are given in
Figure C.1 and Table D.1.
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SIST EN ISO 7029:2017
ISO 7029:2017(E)

Annex A
(informative)

Selected values of the Gaussian distribution
Table A.1 — Values of the multiplier k corresponding to the Gaussian distribution
Q k Q k
0,05 0,95 1,64 0,26 0,74 0,643
0,06 0,94 1,55 0,27 0,73 0,613
0,07 0,93 1,48 0,28 0,72 0,583
0,08 0,92 1,41 0,29 0,71 0,553
0,09 0,91 1,34 0,30 0,70 0,524
0,10 0,90 1,28 0,31 0,69 0,496
0,11 0,89 1,23 0,32 0,68 0,468
0,12 0,88 1,17 0,33 0,67 0,440
0,13 0,87 1,13 0,34 0,66 0,412
0,14 0,86 1,08 0,35 0,65 0,385
0,15 0,85 1,04 0,36 0,64 0,358
0,16 0,84 0,994 0,37 0,63 0,332
0,17 0,83 0,954 0,38 0,62 0,305
0,18 0,82 0,915 0,39 0,61 0,279
0,19 0,81 0,878 0,40 0,60 0,253
0,20 0,80 0,842 0,41 0,59 0,228
0,21 0,79 0,806 0,42 0,58 0,202
0,22 0,78 0,772 0,43 0,57 0,176
0,23 0,77 0,739 0,44 0,56 0,151
0,24 0,76 0,706 0,45 0,55 0,126
0,25 0,75 0,674 0,46 0,54 0,100
0,47 0,53 0,075 3
0,48 0,52 0,050 2
0,49 0,51 0,025 1
  0,50 0,000
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SIST EN ISO 7029:2017
ISO 7029:2017(E)

Annex B
(informative)

Numerical example to illustrate the procedure
B.1 Example
Calculate the hearing threshold deviation exceeded by 25 % of an otologically normal male population
of age 60 years at the audiometric frequency 4 000 Hz.
B.2 Calculation
−3
Step 1:  Table 1, Males, 4 000 Hz, gives α = 3,40 × 10 and β = 2,325.
md md
−3
Step 2:  Formula (1), Y = 60 years, α = 3,40 × 10 and β = 2,325, gives ΔH = 20,21 dB.
md md md,60
−2 −3
Step 3:  Table 2, 4 000 Hz, gives γ = 4,68, γ = 0,455, γ = −5,52 × 10 , γ = 2,95 × 10 ,
0,su 1,su 2,su 3,su
−5 −7
γ = −5,30 × 10 and γ = 2,92 × 10 .
4,su 5,su
NOTE The example concerns 25 % of the population (upper quartile), hence the required parameters are
those for the distribution above the median, i.e. γ (n = 0, 1, 2, …, 5).
n,su
−2 −3 −5
Step 4:  Formula (2), γ = 4,68, γ = 0,455, γ = −5,52 × 10 , γ = 2,95 × 10 , γ = −5,30 × 10
0,su 1,su 2,su 3,su 4,su
−7
and γ = 2,92 × 10 gives s = 18,22 dB.
5,su u
Step 5:  Table A.1, Q = 0,25 (25 %), gives k = 0,674.
Step 6:  Formula (4), ΔH = 20,21 dB, k = 0,674, s = 18,22 dB, gives the required hearing threshold
md,60 u
deviation ΔH = 32,49 dB.
25,60
Step 7:  The result should be rounded to the nearest integer, i.e. 32 dB.
8 © ISO 2017 – All rights reserved

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SIST EN ISO 7029:2017
ISO 7029:2017(E)

Annex C
(informative)

Median values of expected hearing threshold deviations
Key
f frequency, Hz
ΔH hearing threshold deviation, dB
From top to bottom, the curves represent ΔH value
...