1、Designation: E1573 09E1573 18Standard Test Method forEvaluating Measurement and Reporting of Masking Soundin Open Offices Levels Using A-Weighted and One-ThirdOctave Band One-Third-Octave-Band Sound PressureLevels1This standard is issued under the fixed designation E1573; the number immediately foll
2、owing the designation indicates the year oforiginal adoption or, in the case of revision, the year of last 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
3、 is one of a set of standards for evaluatingrelating to the acoustical performance ofcomponents or systems in an open office. open and closed office settings. The other standards in thisset deal with the measurement of the sound attenuation between work stations provided by partialheight space divid
4、ers, vertical surfaces, and acoustical ceiling systems; speech privacy; and theevaluation of masking sound.and speech privacy in open and closed spaces.1. Scope1.1 This test method specifies the procedures that can be procedure used to evaluate the spatial and temporal uniformity ofmeasure the maski
5、ng sound in open offices using A-weighted sound levels. It also specifies the procedure for evaluating themasking sound spectrum and level using one-third octave band terms of A-weighted and one-third-octave-band sound pressurelevels.1.2 The results of this test method can be used to determine if th
6、e masking sound meets a particular specification for spatial andtemporal uniformity if that specification is written in terms ofA-weighted sound levels and if and where the masking sound meetsa particular spectrum shape and level in the office area.(or does not meet) a particular specification.1.3 T
7、his test method must not be used to does not evaluate the acoustical environment in an office space. overall acousticalenvironment. It is intended only to evaluate measure and report the masking sound in an office. This test method, for instance, doesnot evaluate the low frequency levels.rumble nois
8、e found in some offices.1.4 The values stated in SI units are to be regarded as standard. The values in parentheses are for information only.1.5 This standard does not purport to address all of the safety problems,concerns, if any, associated with its use. It is theresponsibility of the user of this
9、 standard to establish appropriate safety safety, health, and healthenvironmental practices anddetermine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in th
10、e Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2C634 Terminology Relating to Building and Environmental AcousticsE1374 Guid
11、e for Open Office Acoustics and Applicable ASTM Standards1 This test method is under the jurisdiction of ASTM Committee E33 on Building and Environmental Acoustics and is the direct responsibility of Subcommittee E33.02on Speech Privacy.Current edition approved April 1, 2009Jan. 1, 2018. Published A
12、pril 2009February 2018. Originally approved in 1993. Last previous edition approved in 20022009 asE1573E1573 09.02. DOI: 10.1520/E1573-09.10.1520/E1573-18.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM
13、Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically poss
14、ible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, We
15、st Conshohocken, PA 19428-2959. United States12.2 ANSIIEC Standards:3S1.11 2004 Specification for Octave-Band and Fractional-Octave Band Analog and Digital FiltersS1.43IEC 61260:1 1997 (R 2007) Specifications for integrating averaging sound level meters Electroacoustics - Octave-bandand fractional-o
16、ctave-band filters - Part 1: SpecificationsIEC 6167261672:1 2002 Electroacoustics-Electroacoustics - Sound Level meters-part 1: specificationsmeters - Part 1:SpecificationsNOTE 1The IEC standards are often adopted by national standards organizations as national standards sometimes with additional un
17、ique nationalstandards numbers assigned.3. Terminology3.1 DefinitionsDefinitions:The3.1.1 The acoustical terminology used in this test method is consistent with the definitions in Terminology C634. acousticalterminology used in this test method is consistent with the definitions in Terminology C634.
18、3.2 Definitions of Terms Specific to This Standard:3.2.1 masking soundsound within an office that reduces the intelligibility of intruding speech and the distraction from activitynoise. Masking sound may be produced by a masking sound system, heating, ventilating, and air conditioning (HVAC) sources
19、,or other sources.of activity noise.3.2.1.1 DiscussionMasking sound is produced and controlled most effectively by an electronic sound masking system.3.2.2 masking sound masking systemthe electronic equipment and loudspeakers used to generate, distribute, and produce-control masking sound throughout
20、 an office space.a treated area.3.2.3 spatial uniformitya condition where the sound pressure levels throughout a defined space do not vary significantly fromthe arithmetic mean sound pressure level. The amount of allowable variation is specified by others such as a consultant, designer,or owner.3.2.
21、4 temporal uniformityat a given position, a condition where the average sound pressure level measured over a short timeinterval does not differ significantly from the average sound pressure level measured over a long time interval. The amount ofallowable variation is specified by others such as a co
22、nsultant, designer, or owner.4. Summary of Test Method4.1 The spatial uniformity conformity of the masking sound in an open office is determined by measuring the A-weightedaverage sound level with a sound level meter or real time analyzer at several locations and comparing these values to the arithm
23、eticmean sound level or to a specified level. The temporal uniformity of the masking sound to a specified curve and level is determinedby measuring theA-weighted sound levels over an extended period of time at one or more locations. The masking sound spectrumand level is determined by measuring the
24、one-third octave band level and the one-third-octave-band sound pressure levels at oneor more locations.sufficiently representative locations with a sound level meter and comparing these values to specified levels.5. Significance and Use5.1 Speech privacy in an open office Acoustical performance is
25、dependent on many factors (see Guide E1374 for a discussionon opengeneral office acoustical considerations). One of these factors is the masking sound in the office. Without masking soundin the open office, confidential speech privacy is not possible at normal voice levels. The four critical acousti
26、cal parameters ofmasking sound are its spatial uniformity, temporal uniformity, spectrum shape, and level. sound. The masking spectrum shape andlevel must conform within specified tolerances throughout the treated area. The measurement and determinationrecording of theseparameters are addressed in t
27、his test method.5.2 The results from this test method can be are used to determine if the masking sound meets a particular specification.6. Test Space6.1 The test space shall include the entire office area area of the building served by the masking system, or as otherwisespecified.system.6.2 The cei
28、ling system of the test space shall be completely finished, including light fixtures and air diffusers.6.3 The floor covering and all wall finishes shall be completely installed prior to testing.3 Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10
29、036, http:/www.ansi.org.International ElectrotechnicalCommission (IEC), 3, rue de Varemb, 1st Floor, P.O. Box 131, CH-1211, Geneva 20, Switzerland, http:/www.iec.ch.E1573 1826.4 To provide the most meaningful information concerning the ability of the masking sound to provide consistent privacy, itis
30、 preferable to test with interior furnishings in place since furniture may influence the distribution of masking sound within thespace. However, this test method may also be used for unfurnished spaces.All interior furnishings shall be in place.6.5 The officetest space shall be unoccupied during the
31、 tests.7. Test Signal7.1 The test signal used for this evaluation may be any of the following:7.1.1 The sound due to the HVAC system, system and the masking sound system, and any other noise sources,sound maskingsystem combined, or7.1.2 The sound due to the masking sound masking system alone, or7.1.
32、3 The sound due to the HVAC system alone.7.2 If the intent is toFor the case described in 7.1.1evaluate the performance of the combination of sounds from the maskingsound system, sound sources associated with the HVAC system and other equipment, then the , the test procedures shall be carriedout con
33、ducted with the masking sound system adjusted as intended to be used in the occupied space. masking system and all otherbackground sound sources operational. The HVAC system shouldshall be operated at its noisiest and quietest settings orconditions.normal daytime condition.7.3 If the intent is toFor
34、 the case described in 7.1.2evaluate the performance of the masking sound system alone, then thebackground sound pressure levels , the test procedures shall be conducted with the sound masking system only. Noise generatedby other background sound sources shall be at least 10 dB lower than the sound
35、pressure levels of the masking sound signal. Forthe measurement of temporal or spatial uniformity, this may require that the sound pressure levels of the masking sound systembe temporarily raised above the design level to provide the proper signal to noise ratio. Care should be taken not to overdriv
36、e themasking sound system, which may cause distortion.below the masking signal in all respective one-third-octave-bands. The HVACsystem shall be shut off and any remaining sounds that may interfere with the measurements shall be noted in the report.7.4 If the intent is to evaluate the performance of
37、 the masking measure the sound generated only by the HVAC system and otherbuilding sources, the HVAC system and other sound sources shall be operated at their noisiest and quietest settings or normaldaytime conditions.7.5 Sound masking features such as adaptive level adjustment or programmable timer
38、 shall be deactivated and set to thespecified base levels during measurements.NOTE 2Testing the HVAC system alone will typically occur in order to verify the need for electronic sound masking and conversely, to determinethe areas within a facility where the HVAC levels may already exceed ideal maski
39、ng sound levels.NOTE 3When the masking system is measured without the HVAC as per 7.1.2, the subsequent restoration of the HVAC may result in combinedambient noise levels that are unacceptable to the occupants.8. Test Instrumentation and Microphone Positioning8.1 Asound level meter or analyzer shall
40、 be used that conforms to, or is better than, Type I,ANSI S1.431997 (R 2007) or class1, IEC 616722002 for a Type 1 meter that has one-third octave band filters.Instrumentation Specification:8.1.1 The sound level meter or analyzer shall be an integrating-averaging type with appropriate microphone tha
41、t conforms toclass 1, IEC 61672:1-2013 requirements.8.1.2 The measurement system shall include one-third-octave-band filters that conform to IEC 61260:1-2014 for class 1.8.1.3 The overall frequency response of the filters for each test band shall conform toANSI S1.112004 for class 1 or better.Testda
42、ta may be acquired on-site or recorded for later analysis. The combined frequency response and other characteristics of themeasurement system and recording device shall meet the class 1 requirements of IEC 61672:1-2013.8.2 Test data may be acquired on-site or recorded for later analysis. The recordi
43、ng device shall have a frequency response of61 dB from 80 to 10 000 Hz.8.2 A microphone with a frequency response of 62 dB from 80 to 10 000 Hz shall be used. The microphone shall be orientedwith respect to the ceiling in the office per the manufacturers recommendation for the type of microphone bei
44、ng used.MicrophoneOrientation and Positioning:8.2.1 The measurement system will typically include a 12.7 mm (12 in.) microphone which will have either a free-field orrandom incidence inherent directivity response and the system may include electronic circuitry allowing the microphone tosimulate eith
45、er directivity response. Results above around 5000 Hz can be influenced by the microphone directivity response, thedegree of diffusivity of the sound field, and the orientation of the microphone if the field is not highly diffuse. These concerns canbe avoided by use of a 6.4 mm (14 in.) microphone.
46、For indoor measurements, it is often assumed that the field is diffusive, anda random incidence response microphone or setting is preferred with the orientation insignificant. Use of a free-field microphonein such fields will result in slightly low readings at higher frequencies. Large open plan spa
47、ces may not be diffuse. Especially ifit is clear to the ear that the dominant sound is from above, it is preferable in such spaces to use either a free-field response withE1573 183the microphone pointed upward, or a random-incidence response with the microphone pointed at about 45 above the horizont
48、al.The microphone directivity response and orientation shall be provided in the report.8.2.2 The microphone position(s) shouldcenter of the microphone sweep position(s) shall be at ear-height for the average seatedperson which is 1.2 m (4 ft) above the floor.8.2.3 The microphone sweep position(s) sh
49、ould be shall be selected if possible so that all measurements are at least 1 m (3.3ft) from any verticalreflective surfaces such as walls, columns, desks, or office furniture. In the event that this criterion cannot bemet, the selected location shall be as far as possible from the closest surface and the location shall be described in the report.metwith the specified sweep diameter, measurements may be as close as 0.5 m (1.6 ft) from surfaces. If the distance between reflectingsurfaces is less than 2 m (6.6 ft), reduce the diameter of the sweep to maintai
