1、Designation: E 1179 07Standard Specification forSound Sources Used for Testing Open Office Componentsand Systems1This standard is issued under the fixed designation E 1179; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year o
2、f last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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 openoffic
3、es or for measuring the laboratory performance of acous-tical components (see Test Methods E 1111 and E 1130).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
4、 special qualification signal. Testsignals required by open office test methods may differ.2. Referenced Documents2.1 ASTM Standards:2C 384 Test Method for Impedance and Absorption ofAcoustical Materials by Impedance Tube MethodC 634 Terminology Relating to Building and Environmen-tal AcousticsE 105
5、0 Test Method for Impedance and Absorption ofAcoustical Materials Using ATube, Two Microphones andA Digital Frequency Analysis SystemE 1111 Test Method for Measuring the Interzone Attenua-tion of Open Office ComponentsE 1130 Test Method for Objective Measurement of SpeechPrivacy in Open Offices Usin
6、g Articulation Index2.2 ANSI Standards:S1.4 Specification for Sound Level Meters3S1.6 Preferred Frequencies, Frequency Levels, and BandNumbers for Acoustical Measurements3S1.11 Specification for Octave Band and Fractional OBAnalog and Digital Filters3S1.43 Specifications for Integrating-Averaging So
7、und LevelMeters33. Terminology3.1 Definitions:3.1.1 The acoustical terminology used in this specificationis consistent with Terminology C 634.3.2 Descriptions of Terms Specific to This Standard:3.2.1 directivity measurementthe measurement used todetermine directivity as defined in 4.2.3.2.2 qualific
8、ation signala test signal of broadband noiseor bands of white or pink noise as defined in TerminologyC 634.3.2.3 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 defin
9、ed in Terminology C 634:3.3.1 background noise,3.3.2 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 (1 ft) on a side, to reduce spuriou
10、s sound reflections.4.2 DirectivityWith the source driven with the qualifica-tion signal, the maximum and minimum sound pressure levelswithin any one-third octave band, from 200 to 3150 Hzmeasured at a distance of 1.0 m (39 in.) from the source point,at any angle up to and including 25 in any direct
11、ion from theloudspeaker axis, shall differ by 2 dB or less. At frequenciesabove 3150 Hz, the difference can be 3dB or less.NOTE 1At angles beyond 25 from the loudspeaker axis, the sourceshall produce lower levels than within the 50 included angle.NOTE 2The directivity requirement may be met by using
12、 more thanone 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 free sound field. The preferred test environment is an1This specification is under the jurisdiction of ASTM
13、 Committee E33 onBuilding and Environmental Acoustics and is the direct responsibility of Subcom-mittee E33.02 on Open Plan Spaces.Current edition approved Oct. 1, 2007. Published November 2007. Originallyapproved in 1987. Last previous edition approved in 2003 as E 1179 87 (2003).2For referenced AS
14、TM standards, 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.,4t
15、h Floor, New York, NY 10036, http:/www.ansi.org.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.anechoic room with surfaces that have a minimum normalincidence sound absorption coefficient of 0.990 at all frequen-cies above 175 Hz as
16、 measured in accordance with TestMethods C 384 or E 1050 or, by the use of other methods, canbe shown to be essentially anechoic between 200 Hz and 5000Hz. Alternatively, an outdoor environment may be used if it isshown that sound reflections do not influence the data.5.2 Test Instruments:5.2.1 The
17、measurement microphone, amplifier, and levelmeter used to measure sound pressure levels shall satisfy therequirements of ANSI S1.4 for Type 1 or better sound levelmeters except that weighting networks are not required.5.2.2 A free field microphone shall be used, that is, one thathas its flattest fre
18、quency response for sounds arriving normal tothe diaphragm.5.2.3 One-third octave filters shall meet the requirements ofANSI S1.11 for Class III, Type R or Type E filters.5.3 Qualification Sound OutputWhen the sound source isdriven with the qualification signal, the sound output shall beadequate to
19、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 broadband noise usually meet thisrequirement.NOTE 4
20、The background noise consists of the ambient noise and theinternal noise of the measuring instruments, as defined in TerminologyC 634.5.4 Directivity MeasurementThe directivity of the soundsource shall be verified by driving the source with thequalification signal and measuring the sound pressure le
21、vels atmeasurement points that include those shown in Fig. 1. Forthese measurements, the axis of the microphone shall beoriented along the line from the measurement point to thesource point with the microphone diaphragm facing the source.This shall be carried out at each one-third octave-band pre-fe
22、rred center frequency from 200 to 5000 Hz defined in ANSIS1.6. At a minimum, the data shall be obtained at sevenmeasurement points in each of two perpendicular planes, suchas the horizontal and vertical planes, at a distance of 1 m (3.3ft) from the source point.5.5 It is recommended that the source
23、be certified per 5.4prior 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 test data for sources that meet this specification.7. Keywords7.1 loudspeaker; o
24、pen office; open office components; openoffice components and systems; sound; sound source directiv-ity; sound sourcesFIG. 1 Measurement Points for Sound Source DirectivityE1179072ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item m
25、entionedin 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.This standard is subject to revision at any time by the responsible technical committ
26、ee 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 International Headquarters. Your comments will receive careful consideration at a meet
27、ing 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 below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, P
28、O 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).E1179073
