BS ISO 28961:2012 BSl Standards Publication Acoustics Statistical distribution of hearing thresholds of otologically normal persons in the age range from 18 years to 25 years under free-field listening conditions bsi. ..making excellence a habit. BSISO28961:2012 BRITISHSTANDARD National foreword This British Standard is the UK implementation ofISO 28961:2012. The UK participation in its preparation was entrusted to Technical Committee EH/1/1, Hearing. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. @The British Standards Institution 2012 ISBN9780580700804 ICS 13.140 Compliance with a British Standard cannot confer immunity from legal obligations. This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31January2012. Amendments issued since publication Date Text affected BSISO28961:2012 INTERNATIONAL ISO STANDARD 28961 First edition 2012-01-15 AcousticsStatistical distribution of hearing thresholds of otologically normal persons in the age range from 18 years to 25 years under free-field listening conditions AcoustiqueRepartition statistique des niveaux liminaires d'audition de personnes otologiquementnormales agees de 18a 25ansdansdes conditions d'ecoute en champ libre Reference number ISO 28961:2012(E) @ISO2012 BSISO28961:2012 ISO28961:2012(E) COPYRIGHTPROTECTEDDOCUMENT @ ISO 2012 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 IsO at the address below or ISO's member body in the country of the requester. ISO copyright office Case postale 56 · CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail [email protected] Web www.iso.org Published in Switzerland ii @ ISO 2012 -All rights reserved BSISO28961:2012 ISO28961:2012(E) Contents Page Foreword iv Introduction. 1 Scope. 2 Normative references. 3 Calculation of percentiles of hearing threshold distribution 3.1 General. 3.2 Thresholddistributionatfrequencieslowerthan10000Hz. 3.3 Threshold distribution at 10 000 Hz and higherfrequencies AnnexA (informative)Numerical examples to illustratetheprocedure. 5 AnnexB(informative)Selectedvaluesofthestatisticaldistributionofhearingthresholdsof otologicallynormal persons in the agerange 18 years to25 years inclusive ..6 AnnexC (informative)Selectedvaluesof 9 Annex D (informative) Notes on the derivation of the statistical distribution of normal hearing thresholds .10 Bibliography. @ ISO 2012 -All rights reserved ili BSISO28961:2012 ISO 28961:2012(E) Foreword Iso (the International Organization for Standardization) is a worldwide federation of national standards bodies (lSOmemberbodies).TheworkofpreparingInternationalStandardsisnormallycarriedoutthroughISo Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. InternationalStandardsaredraftedinaccordancewiththerulesgivenintheISO/lECDirectives,Part2 The main task of technical committees is to prepare International Standards. Draft International Standards International Standard requires approval by at least 75 % of the member bodies casting a vote. 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. ISO28961waspreparedbyTechnicalCommitteeISO/TC43,Acoustics iv ISO2012-All rightsreserved BSISO28961:2012 ISO28961:2012(E) Introduction The threshold of hearing in a free sound field is specified in ISO 226 and ISO 389-7. Threshold data in these median values of hearing thresholds. However, other values on the threshold distribution of individuals are who might be able to detect a