ISO INTERNATIONAL STANDARD 7731 Second edition 2003-11-01 Ergonomics Danger signals for public and work areas Auditory danger signals Ergonomie - Signaux de danger pour lieux publics et lieux de travail - Signaux de danger auditifs Reference number ISO 7731:2003(E) ISO @ ISO 2003 ISO 7731:2003(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In accepts no liability in this area. Adobe is a trademarkof AdobeSystems Incorporated. Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by IsO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below ?ISO2003 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, 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 Licencedby Standards New ZealandtoBartons Sound SystemsLtd Order#243313/Downloaded: 2020-01-28 ii ISO 7731:2003(E) Contents Page Foreword. .iv Introduction 1 Scope 2 Normative references . 3 Terms, definitions and symbols. 4 Safety requirements 4.1 General. 4.2 Recognition 4.2.1 Introduction 4.2.2 Audibility.. 4.2.3 Distinctiveness.. 4.2.4 Unambiguity .... 4.2.5 Moving sources... 4.3 Review of the signal.. 4.4 Recommended maximum level of the danger signal. 5 Test methods..... 5.1 Measurement equipment.................. 5.2 Objective acoustic measurements. 5.2.1 General.... 5.2.2 Weighted measurements 5.2.3 Measurements made in the frequency domain.... 5.2.4 Measurement of the auditory signal with ambient noise present. 5.3 Subjective test method... 6 Design criteria for auditory danger signals.... 6.1 6.2 Sound-pressure level.... 6.3 Spectral characteristics. 6.4 Temporalcharacteristics. 6.4.1 Temporal distribution of the danger signal... 6.4.2 Temporal distribution of the frequencies . 6.4.3 Duration of the danger signals .. 6.5 Information required from suppliers. Annex A (normative) Definitions of symbols.. Annex B (normative) .Calculation of effective masked threshold.................... 9 Annex C (normative) Listening test.. 10 Annex D (informative) Examples of danger signals.. 1 Bibliography .. Licenced by Standards New Zealand to Bartons Sound Systems Ltd Order #243313/Downloaded:2020-01-28 Iso2003—All rightsreserved Single-user licence only, copying and networking prohibited ii ISO 7731:2003(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 non-governmental,inliaisonwithIsO,also take partin the work.Iso collaboratesclosely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/lEC Directives, Part 2 adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. rights. IsO shall not be held responsible for identifying any or all such patent rights. ISO 7731 was prepared by Technical Committee ISO/TC 159, Ergonomics, Subcommittee SC 5, Ergonomics of the physical environment. Thissecondeditioncancelsandreplacesthefirstedition(lSO7731:1986),whichhasbeentechnicallyrevised Licenced by Standa