《环境监测技术》课件-3.2.5噪声的评价量（双语）

环境监测技术Environmental

Monitoring

Technology课题TOPIC噪声的评价量EvaluationIndexofNoise噪声评价的目的是为了有效地提出适合于人们对噪声反应的主观评价量。Thepurposeofnoiseevaluationistoeffectivelyproposesubjectiveevaluationindexsuitableforpeople'sresponsetonoise.噪声的评价量EvaluationIndexofNoise1等响曲线、响度级和响度EqualLoudnessContour，LoudnessLevelandLoudness响度级LoudnessLevel定量确定声音的轻或响的程度。Usedtodeterminethelightnessorloudnessofasoundquantitatively.定义：当某一频率的纯音和1000Hz的纯音听起来同样响时，这时1000Hz纯音的声压级就定义为该待定声音的响度级。Definition:Whenapure-toneofacertainfrequencysoundsasloudasapure-toneat1000Hz,thesoundpressurelevelofthe1000Hzpure-toneisdefinedastheloudnessleveloftheundeterminedsound.LN方（phon）等响曲线EqualLoudnessContour达到同样响度级时频率与声压级的关系曲线。Itreferstothecurvebetweenfrequencyandsoundpressurelevelwhenreachingthesameloudnesslevel.70phon曲线，95dB的30Hz纯音、75dB的100Hz纯音、61dB的4000Hz纯音听起来和70dB的1000Hz纯音一样响。70phoncurve,95dB30Hzpure-tone,75dB100Hzpure-tone,61dB4000Hzpure-tonesoundsasloudas70dB1000Hzpure-tone.听阈Threshold痛阈PainThreshold0phon等响曲线the0phonEqualLoudnessContour最上方的曲线。thetopmostcurve响度Loudness响度级的方值实质上是1000Hz声音声压级的分贝值。Thesquarevalueoftheloudnesslevelisessentiallythedecibelvalueofthe1000Hzsoundpressurelevel.注意：声音的响度级为80phon并不意味着比40phon响一倍。Note:Asoundwithaloudnesslevelof80phondoesnotnecessarilymeanitistwiceasloudas40phon.响度Loudness与主观感受的轻响程度成正比的参量。Aparameterthatisdirectlyproportionaltothevolumeofsubjectiveperception.定义：正常听者判断一个声音比响度级为40phon参考声强响的倍数。Definition:Themultipletimesthatanormallistenerjudgesasoundtobestrongerthanareferencesoundataloudnesslevelof40phon.N宋（sone）2斯蒂文斯响度StevensLoudness掩蔽效应MaskingEffect斯蒂文斯Stevens茨维克Zwicker宽频带噪声Broadbandnoise频带宽度Bandwidth倍频带OctaveBand1/2倍频带1/2OctaveBand1/3倍频带1/3OctaveBand修正因子FCorrectionFactorF0.300.200.15响度指数最大的频带贡献最大；Thefrequencybandwiththehighestloudnessindexcontributesthemost;由于最大响度指数频带声音的掩蔽，其他频带对总响度的贡献应乘上一个小于1的修正因子。Duetothemaskingofthesoundinthemaximumloudnessindexfrequencyband,thecontributionofotherfrequencybandstothetotalloudnessshouldbemultipliedbyacorrectionfactorlessthan1.复合噪声响度计算方法Calculationmethodforcompositenoiseloudness1.测出频带声压级（倍频带或1/3倍频带）。Measurethesoundpressurelevelofthefrequencyband(octavebandor1/3octaveband).复合噪声响度计算方法Calculationmethodforcompositenoiseloudness2.从图4上查出各频带声压级对应的响度指数。FindtheloudnessindexcorrespondingtothesoundpressurelevelofeachfrequencybandfromFigure4.复合噪声响度计算方法Calculationmethodforcompositenoiseloudness3.找出响度指数中的最大值Sm，将各频带响度指数总和中扣除最大值Sm，再乘以相应带宽修正因子F，最后与Sm相加即为复合噪声的响度S。FindthemaximumvalueSmintheloudnessindex,deductthemaximumvalueSmfromthetotalloudnessindexofeachfrequencyband,multiplyitbythecorrespondingbandwidthcorrectionfactorF,andfinallyaddittoSmtoobtaintheloudnessSofthecompositenoise.复合噪声响度计算方法Calculationmethodforcompositenoiseloudness4.求出总响度值后，就可由图4右侧的列线图求出此复合噪声的响度级值，或可按下式计算得出响度级。Aftercalculatingthetotalloudnessvalue,theloudnesslevelofthiscompositenoisecanbecalculatedfromthecolumnchartontherightsideofFigure4,ortheloudnesslevelcanbecalculatedaccordingtothefollowingequation.3计权声级和计权网络WeightedSoundLevelandWeightedNetwork计权声级WeightedSoundLevel通常对不同频率声音的声压级经某一特定的加权修正后，再叠加计算可得到噪声总的声压级，此声压级称为计权声级。Usually,thetotalsoundpressurelevelofnoisecanbeobtainedbyaddingandcalculatingthesoundpressurelevelsofdifferentfrequenciesofsoundafteraspecificweightedcorrection.Thissoundpressureleveliscalledtheweightedsoundlevel.1计权网络WeightedNetwork计权网络是近似以人耳对纯音的响度级频率特性而设计的，通常采用的有A、B、C、D四种计权网络。Weightednetworksaredesignedapproximatelybasedontheloudnesslevelfrequencycharacteristicsofthehumaneartowardspure-tones,typicallyusingfourtypesofweightednetworks:A,B,C,andD.2相当于40phon等响曲线的倒置。Equivalenttotheinversionofthe40phonloudnesscontours.A相当于70phon等响曲线的倒置。Equivalenttotheinversionofthe70phonloudnesscontours.B相当于100phon等响曲线的倒置。Equivalenttotheinversionofthe100phonloudnesscontours.C常用于航空噪声的测量。Commonlyusedformeasuringaviationnoise.D频率/HzA计权修正/dB频率/HzA计权修正/dB20-50.5630-1.925-44.7800-0.831.5-39.41000040-34.61250+0.650-30.21600+1.063-26.22000+1.280-22.52500+1.3100-19.13150+1.2125-16.14000+1.0160-13.45000+0.5200-10.96300-0.1250-8.68000-1.1315-6.610000-2.5400-4.812500-4.3500-3.216000-6.6A计权响应与频率的关系TherelationshipbetweenA-weightedresponseandfrequency4等效连续A声级和昼夜等效声级LeqAandLdn

稳态噪声SteadyNoiseA声级SoundLevelA等效连续A声级LeqA非稳态噪声UnsteadyNoise等效连续A声级LeqA在某个规定时间段内非稳态噪声的A声级，用能量平均的方法，以一个连续不变的A声级来表示该段时间内的噪声级。LeqAistheAsoundlevelofunsteadynoisewithinaspecifiedtimeperiod,representedbyacontinuousandconstantAsoundlevelusingtheenergyaveragingmethod.LeqLpA（t）：噪声信号瞬时A计权声级(InstantaneousA-weightedsoundlevelofnoisesignal)，dBT：总测量时段(Totalmeasurementperiod)，s当测量时采样测量，采样时间间隔相同时，上式可简化为：Whensamplingformeasurementandthesamplingtimeintervalisthesame,theaboveequationcanbesimplifiedas:LpAi：第一个A计权声级(ThefirstA-weightedsoundlevel)，dBn：测量数据个数(Numberofmeasurementdata)昼夜等效声级Ldn

为了考虑噪声在夜间对人们烦恼的增加，规定在夜间测得的所有声级加上10dB(A)作为修正值，再计算昼夜噪声能量的加权平均，由此构成昼夜等效声级这一评价量。Inordertoconsidertheincreasedannoyanceofnoiseonpeopleatnight,itisstipulatedtoadd10dB(A)toallsoundlevelsmeasuredatnightasacorrectionvalue,andthencalculatetheweightedaverageofdayandnightnoiseenergytoformtheevaluationquantityofLdn.LdnLd：昼间（06:00-22:00）测得的噪声能量平均A声级(TheaverageA-levelofnoiseenergymeasuredduringtheday)，dBLn：夜间（22:00-06:00）测得的噪声能量平均A声级(TheaverageA-levelofnoiseenergymeasuredduringthenight)，dB5累积百分声级（统计声级）CumulativePercentileSoundLevel(StatisticalSoundLevel)累积百分声级StatisticalSoundLevel在评价区域环境噪声和交通噪声时，常用的是累积百分声级，又称统计声级。Whenevaluatingregionalenvironmentalnoiseandtrafficnoise,thecommonlyusedmethodisCumulativePercentileSoundLevel,alsoknownasStatisticalSoundLevel.Lx表示在测量时间内高于L的声级所占的时间为n%。LxrepresentsthetimeoccupiedbysoundlevelshigherthanLduringthemeasurementtime,whichisn%.相当于本底噪声级EquivalenttobackgroundnoiselevelL90相当于中值噪声级EquivalenttomediannoiselevelL50相当于峰值噪声级EquivalenttopeaknoiselevelL10累积百分声级一般只用于有较好正态分布的噪声评价。StatisticalSoundLevelisgenerallyonlyusedfornoiseevaluationwithgoodnormaldistribution.6交通噪声指数(TNI)TrafficNoiseIndex(TNI)交通噪声指数TrafficNoiseIndex用统计声级来评价机动车辆对周围环境的干扰程度，是城市道路交通噪声评价的一个重要参量。TNIusesstatisticalsoundleveltoevaluatethedegreeofinterferenceofmotorvehiclesonthesurroundingenvironment,whichisanimportantparameterforevaluatingurbanroadtrafficnoise.交通噪声指数(TNI)的测量是在24h周期内进行大量的A声级取样，取样时间不连续，将取样后的声级（如100个或200个）从大到小排列，求得累积百分声级L10和L90。ThemeasurementofTNIinvolvestakingalargenumberofA-levelsamplesovera24-hourperiod,withdiscontinuoussamplingtimes.Thesampledsoundlevels(suchas100or200)arearrangedindescendingordertoobtainthecumulativepercentagesoundlevelsL10andL90.L10：峰值噪声(peaking