BS ISO BRITISH STANDARD 13474:2009 Acoustics - Framework for calculating a distribution of sound exposure levels for impulsive sound events for the purposes of environmental noise assessment ICS 17.140.01 BSi NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BritishStandards BSISO 13474:2009 National foreword This British Standard is the UK implementation of ISO 13474:2009. It supersedes DD ISO/TS 13474:2003 and which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee EH/1/3, Residential and industrial noise. 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. CompliancewithaBritishStandard cannotconferimmunity from legal obligations. 2013Lice This British Standard Amendments/corrigenda issued since publication was published under the authority ofthe Standards Policy and Strategy Date Comments Committee on 28 February 2010. CBSI 2010 HH Lbal ISBN 978 0 580 54119 3 BS IS0 13474:2009 INTERNATIONAL ISO STANDARD 13474 Versloncorreclas0f03/01/2015,(o)TheBritishStar First edition 2009-06-15 Acoustics Framework for calculating a distribution of sound exposure levels for impulsive sound events for the purposes of environmental noise assessment AcoustiqueCadre pourle calcul d'unedistributiondes niveaux d'expositionsonorepourlessonsimpulsionnelspourlesbesoinsde I'evaluationdubruitenvironnemental ,Verskoncorreclas.af03/01/2015, (c)TheBriltishSt Reference number ISO 13474:2009(E) GO @ISO2009 BS ISO 13474:2009 ISO13474:2009(E) PDF disclaimer . (c) The Brllish 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 downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat accepts no liability in this area. Adobe is a trademark of Adobe Systems 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. (c)TheBrlish Stan of03/01/2015, COPYRIGHTPROTECTEDDOCUMENT @ISO2009 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 主 Casepostale56:CH-1211Geneva20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail [email protected] Web www.iso.org Published in Switzerland = Iso 2009-All rights reserved BSISO13474:2009 ISO13474:2009(E) Contents Page Foreword Introduction.. Scope 1 2 Normative references.. 3 Terms and definitions.. 2 4 Basic equations .6 4.1 General. 4.2 Probability of occurrence ... 6 4.3 4.4 Frequency-weighted sound exposure level.... 4.5 Long-term average single-event sound exposure level 4.6 Equivalent level from multiple events... 10 5 Calculation of a statistical distribution 6 Calculation of attenuation . 6.1 14 6.2 Geometric divergence 14 6.3 Atmosphericabsorption 14 6.4 Insertionlossbyscreeningobjects 15 6.5 Terrain shielding..... 6.6 Contributions to excess attenuation 16 6.6.1 General. 16 6.6.2 Refraction 16 6.6.3 Ground reflection and absorption ... 17 7 Classification 19 7.1 General. 19 7.2 Classification of atmospheric absorption.... .19 7.3 Classification of excess attenuation .. 19 7.3.1 19 7.3.2 Lookuptable requirements .20 7.3.3 Range-dependent sound speed profiles. 21 7.3.4 Directed sound speed prof