1、Designation: C634 13Standard Terminology Relating toBuilding and Environmental Acoustics1This standard is issued under the fixed designation C634; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number
2、in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.INTRODUCTIONIn some of the entries, those that are measures of physical quantities, the term is followed by threeitems: symbol, dimensions, and unit. The
3、symbol, in italics, stands for the magnitude of the quantityin mathematical expressions. The dimensions of a quantity express its measure in terms of threefundamental quantities: M for mass, L for length, and T for time. Speed, for instance, is the quotientobtained when the distance an object moves
4、is divided by the time involved. The dimensions areLT1, the negative exponent indicating division. The unit is consistently in SI, Le SystmeInternational dUnits. Those still using the cgs (centimetre-gram-second) or the inchpound system ofunits are referred for most of the conversion factors to IEEE
5、/ ASTM SI 10. A few conversion factorsare listed in Section 4 of this terminology.The dimensions of a quantity are the same regardless of the units in which the quantity is measured.Speed has the dimensions LT1 whether it is measured in miles per hour, feet per second, or metresper second. Quantitie
6、s with different dimensions are not the same. Flow resistance and specific flowresistance, for instance, are quantities of different kinds even though the names are similar. On theother hand, quantities with the same dimensions are not necessarily of the same kind. Sound energydensity, for instance,
7、 has the same dimensions as sound pressure, ML1T2, but it is not a kind ofsound pressure. Nor is absorption with the dimensions L2 a kind of area.1. Scope1.1 This terminology covers terms and definitions related toenvironmental acoustics. Only definitions common to two ormore standards under the jur
8、isdiction of Committee E33 arelisted here. The purpose of this terminology is to promoteuniformity of key definitions. Definitions pertinent to only onestandard and exceptions to the definitions listed below arecontained in the individual standards and should be used whenfollowing those standards.2.
9、 Referenced Documents2.1 ASTM Standards:2C423 Test Method for SoundAbsorption and SoundAbsorp-tion Coefficients by the Reverberation Room MethodC367 Test Methods for Strength Properties of PrefabricatedArchitectural Acoustical Tile or Lay-In Ceiling PanelsC384 Test Method for Impedance and Absorptio
10、n of Acous-tical Materials by Impedance Tube MethodC522 Test Method for Airflow Resistance of AcousticalMaterialsC635 Specification for the Manufacture, Performance, andTesting of Metal Suspension Systems for Acoustical Tileand Lay-in Panel CeilingsC636 Practice for Installation of Metal Ceiling Sus
11、pensionSystems for Acoustical Tile and Lay-In PanelsC667 Specification for Prefabricated Reflective InsulationSystems for Equipment and Pipe Operating at Tempera-tures above Ambient AirC871 Test Methods for Chemical Analysis of Thermal Insu-lation Materials for Leachable Chloride, Fluoride, Silicate
12、,and Sodium IonsE90 Test Method for Laboratory Measurement of AirborneSound Transmission Loss of Building Partitions andElementsE336 Test Method for Measurement of Airborne SoundAttenuation between Rooms in BuildingsE413 Classification for Rating Sound InsulationE477 Test Method for Laboratory Measu
13、rements of Acous-tical andAirflow Performance of Duct Liner Materials andPrefabricated Silencers1This terminology is under the jurisdiction of ASTM Committee E33 onBuilding and Environmental Acoustics and is the direct responsibility of Subcom-mittee E33.07 on Definitions and Editorial.Current editi
14、on approved Sept. 1, 2013. Published December 2013. Originallyapproved in 1969. Last previous edition approved in 2011 as C634 11. DOI:10.1520/C0634-13.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMSta
15、ndards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1E492 Test Method for Laboratory Measurement of ImpactSound Transmission Through Floor-Ceiling A
16、ssembliesUsing the Tapping MachineE497 Practice for Installing Sound-Isolating LightweightPartitions (Withdrawn 2008)3E557 Guide for Architectural Design and Installation Prac-tices for Sound Isolation between Spaces Separated byOperable PartitionsE596 Test Method for Laboratory Measurement of Noise
17、Reduction of Sound-Isolating EnclosuresE756 Test Method for Measuring Vibration-Damping Prop-erties of MaterialsE795 Practices for Mounting Test Specimens During SoundAbsorption TestsE966 Guide for Field Measurements of Airborne SoundAttenuation of Building Facades and Facade ElementsE989 Classifica
18、tion for Determination of Impact InsulationClass (IIC)E1007 Test Method for Field Measurement of TappingMachine Impact Sound Transmission Through Floor-Ceiling Assemblies and Associated Support StructuresE1014 Guide for Measurement of Outdoor A-WeightedSound LevelsE1042 Classification for Acoustical
19、ly Absorptive MaterialsApplied by Trowel or SprayE1050 Test Method for Impedance and Absorption ofAcoustical Materials Using a Tube, Two Microphones anda Digital Frequency Analysis SystemE1110 Classification for Determination ofArticulation ClassE1111 Test Method for Measuring the Interzone Attenuat
20、ionof Open Office ComponentsE1123 Practices for Mounting Test Specimens for SoundTransmission Loss Testing of Naval and Marine ShipBulkhead Treatment MaterialsE1129/E1129M Specification for Thermocouple ConnectorsE1124 Test Method for Field Measurement of Sound PowerLevel by the Two-Surface MethodE1
21、130 Test Method for Objective Measurement of SpeechPrivacy in Open Plan Spaces Using Articulation IndexE1179 Specification for Sound Sources Used for TestingOpen Office Components and SystemsE1222 Test Method for Laboratory Measurement of theInsertion Loss of Pipe Lagging SystemsE1264 Classification
22、 for Acoustical Ceiling ProductsE1265 Test Method for Measuring Insertion Loss of Pneu-matic Exhaust SilencersE1289 Specification for Reference Specimen for SoundTransmission LossE1332 Classification for Rating Outdoor-Indoor Sound At-tenuationE1374 Guide for Open Office Acoustics and ApplicableASTM
23、 StandardsE1408 Test Method for Laboratory Measurement of theSound Transmission Loss of Door Panels and DoorSystems (Withdrawn 2009)3E1414 Test Method for Airborne Sound Attenuation Be-tween Rooms Sharing a Common Ceiling PlenumE1433 Guide for Selection of Standards on EnvironmentalAcoustics (Withdr
24、awn 2010)3E1503 Test Method for Conducting Outdoor Sound Mea-surements Using a Digital Statistical Sound AnalysisSystemE1573 Test Method for Evaluating Masking Sound in OpenOffices Using A-Weighted and One-Third Octave BandSound Pressure LevelsE1574 Test Method for Measurement of Sound in Residen-ti
25、al SpacesE1686 Guide for Applying Environmental Noise Measure-ment Methods and CriteriaE1704 Guide for Specifying Acoustical Performance ofSound-Isolating EnclosuresE1779 Guide for Preparing a Measurement Plan for Con-ducting Outdoor Sound Measurements (Withdrawn2012)3E1780 Guide for Measuring Outdo
26、or Sound Received froma Nearby Fixed SourceE2179 Test Method for Laboratory Measurement of theEffectiveness of Floor Coverings in Reducing ImpactSound Transmission Through Concrete FloorsE2202 Practice for Measurement of Equipment-GeneratedContinuous Noise for Assessment of Health HazardsE2235 Test
27、Method for Determination of Decay Rates forUse in Sound Insulation Test MethodsE2249 Test Method for Laboratory Measurement of Air-borne Transmission Loss of Building Partitions and Ele-ments Using Sound IntensityE2459 Guide for Measurement of In-Duct Sound PressureLevels from Large Industrial Gas T
28、urbines and FansE2638 Test Method for Objective Measurement of theSpeech Privacy Provided by a Closed RoomIEEE/ ASTM SI 10 Standard for Use of the InternationalSystem of Units (SI): The Modern Metric System2.2 ANSI Standard:ANSI S1.4 Specification for Sound Level Meters4ANSI S1.6 Preferred Frequenci
29、es, Frequency Levels, andBand Numbers for Acoustical MeasurementsANSI S1.11 Octave-Band and Fractional Octave-Band Ana-log and Digital Filters, Specifications for3. Terminology3.1 If the term sought by the user cannot be found in 3.2,itmay be found in 4.1.3.2 Definitions:acoustic impedance, Z R + jX
30、; ML4T1; mks acousticohm (Pas/m3)of a surface, for a given frequency, thecomplex quotient obtained when the sound pressure aver-aged over the surface is divided by the volume velocitythrough the surface. The real and imaginary components arecalled, respectively, acoustic resistance and acoustic reac
31、-tance.3The last approved version of this historical standard is referenced onwww.astm.org.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.C634 132acoustical barriercontiguous objects such as solid walls,buildings, or ear
32、then berms that substantially block the directpath of sound between a source and receiver, and which, ifthey have an open edge or edges allowing diffraction aroundthem, are sufficiently wide and high to cause significantreduction of the sound traveling from the source to thereceiver.acoustical mater
33、ialany material considered in terms of itsacoustical properties. Commonly and especially, a materialdesigned to absorb sound.admittance ratio, yc gcjbc; dimensionlessthereciprocal of the impedance ratio. The real and imaginarycomponents are called, respectively, conductance ratio andsusceptance rati
34、o.airborne soundsound that arrives at the point of interest,such as one side of a partition, by propagation through air.airflow resistance, R;ML4T1; mks acoustic ohm (Pas/m3)the quotient of the air pressure difference across aspecimen divided by the volume velocity of airflow throughthe specimen. Th
35、e pressure difference and the volumevelocity may be either steady or alternating.airflow resistivity, ro; ML3T1; mks rayl/m (Pas/m2)of ahomogeneous material, the quotient of its specific airflowresistance divided by its thickness.ambient noisethe composite of airborne sound from manysources near and
36、 far associated with a given environment.No particular sound is singled out for interest.arithmetic mean sound pressure levelof several relatedsound pressure levels measured at different positions ordifferent times, or both, in a specified frequency band, thesum of the sound pressure levels divided
37、by the number oflevels.DISCUSSIONThe arithmetic mean sound pressure level is sometimesused to approximate the average sound pressure level. The accuracyof this approximation depends upon the range of sound pressure levels.average sound pressure levelof several related soundpressure levels measured a
38、t different positions or differenttimes, or both, in a specified frequency band, ten times thecommon logarithm of the arithmetic mean of the squaredpressure ratios from which the individual levels were de-rived.DISCUSSION1An average sound pressure level obtained by aver-aging the A-weighted sound le
39、vel continuously over a specified periodis called the time-average sound level.DISCUSSION2Since, by definition, a squared pressure ratio, pi2/p02, is equal to 10Li/10, average sound pressure level is calculated fromthe expression:Li5 10logS1n(i51n10Li/10DLp= average sound pressure level, dB,n = numb
40、er of individual sound pressure levels,pi= rms pressure at an individual position or time, or both,Pa,p0= 20 Pa, reference sound pressure, andLi= an individual sound pressure level, dB.If conditions warrant, an integral expression may be used:Lp5 10logS1T*t1t2p2t!/p02! dtDLp= average sound pressure
41、level during a specified timeinterval, dB,T =t2t1= a specified time interval, s, min, h, or day,p(t) = instantaneous sound pressure, Pa, andp0= 20 Pa, reference sound pressure.background noisenoise from all sources unrelated to aparticular sound that is the object of interest. Backgroundnoise may in
42、clude airborne, structureborne, and instrumentnoise.cutoff frequencyof an anechoic wedge or set of wedges, thelowest frequency above which the normal incidence soundabsorption coefficient is at least 0.990.dampto cause a loss or dissipation of the oscillatory orvibrational energy of an electrical or
43、 mechanical system.decay rate, d; T1; dB/sfor airborne sound, the rate ofdecrease of sound pressure level after the source of soundhas stopped; for vibration, the rate of decrease of vibratoryacceleration, velocity, or displacement level after the exci-tation has stopped.decibel, dBthe term used to
44、identify ten times the commonlogarithm of the ratio of two like quantities proportional topower or energy. (See level, sound transmission loss.)Thus, one decibel corresponds to a power ratio of 100.1andn decibels corresponds to a power ratio of (100.1)n.DISCUSSIONSince the decibel expresses the rati
45、o of two likequantities, it has no dimensions. It is, however, common practice totreat “decibel” as a unit as, for example, in the sentence, “The averagesound pressure level in the room is 45 decibels.”diffractiona change in the direction of propagation of soundenergy in the neighborhood of a bounda
46、ry discontinuity,such as the edge of a reflective or absorptive surface.diffuse sound fieldthe sound in a region where the intensityis the same in all directions and at every point.direct sound fieldthe sound that arrives directly from asource without reflection.dummy microphonea microphone substitu
47、te which haselectrical characteristics identical to a functionalmicrophone, but which has essentially no sensitivity toincident sound pressure.field sound transmission class, FSTCsound transmissionclass calculated in accordance with Classification E413using values of field transmission loss.field tr
48、ansmission loss, FTLsound transmission loss mea-sured in accordance with Annex A1 of Test Method E336.flanking transmissiontransmission of sound from thesource to a receiving location by a path other than that underconsideration.C634 133impact insulation class, IICa single-number rating derivedfrom
49、measured values of normalized impact sound pressurelevels in accordance withAnnexA1 of Test Method E492.Itprovides an estimate of the impact sound insulating perfor-mance of a floor-ceiling assembly.impedance ratio, z/c r/c + jx/c; dimensionlesstheratio of the specific normal acoustic impedance at a surfaceto the characteristic impedance of the medium. The real andimaginary components are called, respectively, resistanceratio and reactance ratio.impulsive sound, na brief, intrusive sound, su
