1、Designation:E263810Standard Test Method forObjective Measurement of the Speech Privacy Provided bya Closed Room1This standard is issued under the fixed designation E2638;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of las
2、t revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.INTRODUCTIONThis test method is one of a set of standards for evaluating speech privacy in buildings.It isdesigned to measure the degree
3、of speech privacy provided by a closed room,indicating the degreeto which conversations occurring within are kept private from listeners outside the room.A relatedmethod(Test Method E1130)deals with assessing speech privacy in open plan spaces.1.Scope1.1 This test method describes a test procedure f
4、or measur-ing the degree of speech privacy provided by a closed room,for conversations occurring within the room,and with potentialeavesdroppers located outside the room.1.2 The degree of speech privacy measured by this methodis that due to the sound insulation of the room structurethewalls,floor,ce
5、iling and any other elements of the roomboundariesand to the background noise at listening positionsoutside the closed the room.1.3 Potential eavesdroppers are assumed to be unaided byelectronic or electroacoustic equipment,and not touching theroom boundaries.Determined efforts to eavesdrop are nota
6、ddressed.1.4 The method may be applied to any enclosed room,whether specifically intended to be protected against eaves-dropping or not.1.5 The method does not set criteria for adequate speechprivacy.A non-mandatory appendix provides guidance on howthe results of this test method may be used to esti
7、mate theprobability of an eavesdropper being able to understand speechoutside a closed room,and how to set criteria for such rooms.1.6 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.7 This standard does not purport to address
8、all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2C634 Terminology Relat
9、ing to Building and EnvironmentalAcousticsE1130 Test Method for Objective Measurement of SpeechPrivacy in Open Plan Spaces Using Articulation Index2.2 ANSI Standards:S1.11 Specification for Octave-Band and Fractional-Octave-Band Analog and Digital Filters3S1.43 Specifications for Integrating-Averagi
10、ng Sound LevelMeters33.Terminology3.1 The following terms used in this test method havespecific meanings that are defined in Terminology C634:airborne soundsound attenuationaverage sound pressure levelsound isolationbackground noisesound leveldecibelsound pressure levellevelsource roomoctave bandwhi
11、te noisepink noise3.2 Definitions of Terms Specific to This Standard:3.2.1 receiving pointa location outside the closed roomunder consideration where someone might accidentally over-hear or deliberately listen to speech occurring within the room.1This test method is under the jurisdiction ofASTM Com
12、mittee E33 on Buildingand Environmental Acoustics and is the direct responsibility of SubcommitteeE33.02 on Speech Privacy.Current edition approved May 1,2010.Published May 2010.Originallyapproved in 2008.Last previous edition approved in 2008 as E263808 DOI:10.1520/E2638-10.2For referenced ASTM sta
13、ndards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New Yo
14、rk,NY 10036,http:/www.ansi.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.2.2 speech privacy class(SPC)an objective rating of thespeech privacy provided by a closed room,calculated as a sumof factors related to sound isolation prov
15、ided by the room,andbackground noise at the receiving point.4.Summary of Test Method4.1 Sound is generated at a high level in the closed roomunder consideration.To improve spatial uniformity,a sourceloudspeaker is to be placed successively at two or morelocations within the room.4.2 Receiving points
16、 outside the closed room under consid-eration that are near potential weak spots in the soundinsulation or that are possible locations for an eavesdropper areselected for measurement.4.3 With the source operating in each successive location,measurements of sound pressure level are made within theclosed room to obtain source room levels,and at receivingpoints outside the closed room to obtain received levels.4.4 With the source turned off,measurements of soundpressure level are made at the receiv