1、Designation: E1179 11Standard Specification forSound Sources Used for Testing Open Office Componentsand Systems1This standard is issued under the fixed designation E1179; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification states the requirements for soundsources used for measuring the speech privacy between openoffices
3、and for measuring the laboratory performance ofacoustical components (see Test Methods E1111 and E1130).1.2 The sound source shall be a loudspeaker located in anenclosure driven with an appropriate test signal.1.3 This specification describes the sound source andmethod of qualifying it using a speci
4、al qualification signal. Testsignals required by open office test methods may differ.1.4 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.2. Referenced Documents2.1 ASTM Standards:2C384 Test Method for Impedance andAbsorption ofA
5、cous-tical Materials by Impedance Tube MethodC634 Terminology Relating to Building and EnvironmentalAcousticsE1050 Test Method for Impedance and Absorption ofAcoustical Materials Using a Tube, Two Microphones anda Digital Frequency Analysis SystemE1111 Test Method for Measuring the InterzoneAttenuat
6、ionof Open Office ComponentsE1130 Test Method for Objective Measurement of SpeechPrivacy in Open Plan Spaces Using Articulation Index2.2 ANSI Standards:3S1.4 Specification for Sound Level MetersS1.6 Preferred Frequencies, Frequency Levels, and BandNumbers for Acoustical MeasurementsS1.11 Specificati
7、on for Octave Band and Fractional OBAnalog and Digital FiltersS1.43 Specifications for Integrating-Averaging Sound LevelMeters2.3 IEC Standards:461260 ElectroacousticsOctave and fractional-octave bandfilters616721 ElectroacousticsSound Level MetersPart 1:Specifications3. Terminology3.1 Definitions:3
8、.1.1 The acoustical terminology used in this specificationis consistent with Terminology C634.3.2 Descriptions of Terms Specific to This Standard:3.2.1 directivity measurementthe measurement used todetermine directivity as defined in 4.2.3.2.2 qualification signala test signal of broadband noiseor b
9、ands of white or pink noise as defined in TerminologyC634.3.2.3 source pointthe point at which the loudspeaker axisintersects the front plane of the loudspeaker (see Fig. 1).3.3 The following terms in this standard have specificmeanings that are defined in Terminology C634:3.3.1 background noise,3.3
10、.2 pink noise,3.3.3 sound pressure level, and3.3.4 white noise4. Sound Source Specifications4.1 Sound Source DescriptionThe sound source shall be aloudspeaker enclosed in a box that has a maximum dimensionof 0.30 m on a side.4.2 DirectivityWith the source driven with the qualifica-tion signal, the m
11、aximum and minimum sound pressure levelsof any one-third octave band, from 200 to 3150 Hz measuredat a distance of 1.0 m from the source point, at any angle up toand including 25 in any direction from the loudspeaker axis,shall differ by no more than 2 dB. At frequencies above 3150Hz, the difference
12、 shall be no more than 3dB.NOTE 1At angles beyond 25 from the loudspeaker axis, the source1This specification is under the jurisdiction of ASTM Committee E33 onBuilding and Environmental Acoustics and is the direct responsibility of Subcom-mittee E33.02 on Open Plan Spaces.Current edition approved N
13、ov. 1, 2011. Published December 2011. Originallyapproved in 1987. Last previous edition approved in 2007 as E1179 07. DOI:10.1520/E1179-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume
14、 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 York, NY 10036, http:/www.ansi.org.4Available from International Electrotechnical Commission (IEC), 3, rue deVaremb, P.O. Box 131,
15、 CH-1211 Geneva 20, Switzerland, http:/www.iec.ch.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.may produce lower sound pressure levels than within the 50 includedangle.NOTE 2The directivity requirement may be met by using more tha
16、none loudspeaker, each one used separately to cover a different portion ofthe test frequency range.5. Source Qualification5.1 Test EnvironmentThe measurements shall be carriedout in a sound field, essentially free of acoustical reflections.The preferred test environment is an anechoic room withsurfa
17、ces that have a minimum normal incidence sound absorp-tion coefficient of 0.990 at all frequencies above 175 Hz asmeasured in accordance with Test Methods C384 or E1050 or,by the use of other methods, can be shown to be essentiallyanechoic between 200 Hz and 5000 Hz. Alternatively, anoutdoor environ
18、ment may be used if it is shown that soundreflections do not influence the data.5.2 Test Instruments:5.2.1 The measurement system used to measure soundpressure levels shall satisfy the accuracy requirements ofANSIS1.4 or IEC 61672-1 Type 1 sound level meters except thatweighting networks are not req
19、uired.5.2.2 The microphone shall meet the requirements of eitherIEC 616721 or ANSI S1.4. For microphones meeting ANSIS1.4, the microphone shall be oriented so the sound in incidenton the microphone at the calibration angle of incidence for themicrophone. For microphones meeting IEC 616721, themicrop
20、hone shall be oriented so the sound is incident on themicrophone from the reference direction.5.2.3 One-third octave filters shall meet the requirements ofANSI S1.11 for Class III, Type R or Type E filters or IEC61260.5.3 Qualification Sound OutputWhen the sound source isdriven with the qualificatio
21、n signal, the sound output shall beadequate to maintain one-third octave-band sound pressurelevels at least 10 dB above the corresponding background noisein each band at each measurement location.NOTE 3Sources which produce anA-weighted sound level of 70 to 90dB at 1 m (3.3 ft) when driven with broa
22、dband noise usually meet thisrequirement.NOTE 4The background noise consists of the ambient noise and theinternal noise of the measuring instruments, as defined in TerminologyC634.5.4 Directivity MeasurementThe directivity of the soundsource shall be verified by driving the source with thequalificat
23、ion signal and measuring the sound pressure levels atmeasurement points that include those shown in Fig. 1. Themicrophone shall be oriented such that the angle between theaxis of the microphone and the line connecting the center of themicrophone diaphragm and the center of the speaker is thesame for
24、 each measurement. This shall be carried out for eachone-third octave with midband frequencies from 200 to 5000Hz defined in ANSI S1.6 or IEC 61260. At a minimum, thedata shall be obtained at seven measurement points in each oftwo perpendicular planes, such as the horizontal and verticalplanes, at a
25、 distance of 1 m from the source point.5.5 It is recommended that the source be characterized per5.4 prior to first use and after repair or replacement of anycomponent in the speakers that can affect directivity.6. Qualification Report6.1 A report shall be made available providing the qualifi-cation
26、 test data for sources that meet this specification.7. Keywords7.1 loudspeaker; open office; open office components; openoffice components and systems; sound; sound source directiv-ity; sound sourcesFIG. 1 Measurement Points for Sound Source DirectivityE1179 112ASTM International takes no position r
27、especting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.Thi
28、s standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM Inte
29、rnational Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown
30、below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).E1179 113
