《環境監測技術》課件-3.2.5噪聲的評價量（雙語）

環境監測技術Environmental

Monitoring

Technology課題TOPIC噪聲的評價量EvaluationIndexofNoise噪聲評價的目的是為了有效地提出適合于人們對噪聲反應的主觀評價量。Thepurposeofnoiseevaluationistoeffectivelyproposesubjectiveevaluationindexsuitableforpeople'sresponsetonoise.噪聲的評價量EvaluationIndexofNoise1等響曲線、響度級和響度EqualLoudnessContour，LoudnessLevelandLoudness響度級LoudnessLevel定量確定聲音的輕或響的程度。Usedtodeterminethelightnessorloudnessofasoundquantitatively.定義：當某一頻率的純音和1000Hz的純音聽起來同樣響時，這時1000Hz純音的聲壓級就定義為該待定聲音的響度級。Definition:Whenapure-toneofacertainfrequencysoundsasloudasapure-toneat1000Hz,thesoundpressurelevelofthe1000Hzpure-toneisdefinedastheloudnessleveloftheundeterminedsound.LN方（phon）等響曲線EqualLoudnessContour達到同樣響度級時頻率與聲壓級的關系曲線。Itreferstothecurvebetweenfrequencyandsoundpressurelevelwhenreachingthesameloudnesslevel.70phon曲線，95dB的30Hz純音、75dB的100Hz純音、61dB的4000Hz純音聽起來和70dB的1000Hz純音一樣響。70phoncurve,95dB30Hzpure-tone,75dB100Hzpure-tone,61dB4000Hzpure-tonesoundsasloudas70dB1000Hzpure-tone.聽閾Threshold痛閾PainThreshold0phon等響曲線the0phonEqualLoudnessContour最上方的曲線。thetopmostcurve響度Loudness響度級的方值實質上是1000Hz聲音聲壓級的分貝值。Thesquarevalueoftheloudnesslevelisessentiallythedecibelvalueofthe1000Hzsoundpressurelevel.注意：聲音的響度級為80phon并不意味著比40phon響一倍。Note:Asoundwithaloudnesslevelof80phondoesnotnecessarilymeanitistwiceasloudas40phon.響度Loudness與主觀感受的輕響程度成正比的參量。Aparameterthatisdirectlyproportionaltothevolumeofsubjectiveperception.定義：正常聽者判斷一個聲音比響度級為40phon參考聲強響的倍數。Definition:Themultipletimesthatanormallistenerjudgesasoundtobestrongerthanareferencesoundataloudnesslevelof40phon.N宋（sone）2斯蒂文斯響度StevensLoudness掩蔽效應MaskingEffect斯蒂文斯Stevens茨維克Zwicker寬頻帶噪聲Broadbandnoise頻帶寬度Bandwidth倍頻帶OctaveBand1/2倍頻帶1/2OctaveBand1/3倍頻帶1/3OctaveBand修正因子FCorrectionFactorF0.300.200.15響度指數最大的頻帶貢獻最大；Thefrequencybandwiththehighestloudnessindexcontributesthemost;由于最大響度指數頻帶聲音的掩蔽，其他頻帶對總響度的貢獻應乘上一個小于1的修正因子。Duetothemaskingofthesoundinthemaximumloudnessindexfrequencyband,thecontributionofotherfrequencybandstothetotalloudnessshouldbemultipliedbyacorrectionfactorlessthan1.復合噪聲響度計算方法Calculationmethodforcompositenoiseloudness1.測出頻帶聲壓級（倍頻帶或1/3倍頻帶）。Measurethesoundpressurelevelofthefrequencyband(octavebandor1/3octaveband).復合噪聲響度計算方法Calculationmethodforcompositenoiseloudness2.從圖4上查出各頻帶聲壓級對應的響度指數。FindtheloudnessindexcorrespondingtothesoundpressurelevelofeachfrequencybandfromFigure4.復合噪聲響度計算方法Calculationmethodforcompositenoiseloudness3.找出響度指數中的最大值Sm，將各頻帶響度指數總和中扣除最大值Sm，再乘以相應帶寬修正因子F，最后與Sm相加即為復合噪聲的響度S。FindthemaximumvalueSmintheloudnessindex,deductthemaximumvalueSmfromthetotalloudnessindexofeachfrequencyband,multiplyitbythecorrespondingbandwidthcorrectionfactorF,andfinallyaddittoSmtoobtaintheloudnessSofthecompositenoise.復合噪聲響度計算方法Calculationmethodforcompositenoiseloudness4.求出總響度值后，就可由圖4右側的列線圖求出此復合噪聲的響度級值，或可按下式計算得出響度級。Aftercalculatingthetotalloudnessvalue,theloudnesslevelofthiscompositenoisecanbecalculatedfromthecolumnchartontherightsideofFigure4,ortheloudnesslevelcanbecalculatedaccordingtothefollowingequation.3計權聲級和計權網絡WeightedSoundLevelandWeightedNetwork計權聲級WeightedSoundLevel通常對不同頻率聲音的聲壓級經某一特定的加權修正后，再疊加計算可得到噪聲總的聲壓級，此聲壓級稱為計權聲級。Usually,thetotalsoundpressurelevelofnoisecanbeobtainedbyaddingandcalculatingthesoundpressurelevelsofdifferentfrequenciesofsoundafteraspecificweightedcorrection.Thissoundpressureleveliscalledtheweightedsoundlevel.1計權網絡WeightedNetwork計權網絡是近似以人耳對純音的響度級頻率特性而設計的，通常采用的有A、B、C、D四種計權網絡。Weightednetworksaredesignedapproximatelybasedontheloudnesslevelfrequencycharacteristicsofthehumaneartowardspure-tones,typicallyusingfourtypesofweightednetworks:A,B,C,andD.2相當于40phon等響曲線的倒置。Equivalenttotheinversionofthe40phonloudnesscontours.A相當于70phon等響曲線的倒置。Equivalenttotheinversionofthe70phonloudnesscontours.B相當于100phon等響曲線的倒置。Equivalenttotheinversionofthe100phonloudnesscontours.C常用于航空噪聲的測量。Commonlyusedformeasuringaviationnoise.D頻率/HzA計權修正/dB頻率/HzA計權修正/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計權響應與頻率的關系TherelationshipbetweenA-weightedresponseandfrequency4等效連續A聲級和晝夜等效聲級LeqAandLdn

穩態噪聲SteadyNoiseA聲級SoundLevelA等效連續A聲級LeqA非穩態噪聲UnsteadyNoise等效連續A聲級LeqA在某個規定時間段內非穩態噪聲的A聲級，用能量平均的方法，以一個連續不變的A聲級來表示該段時間內的噪聲級。LeqAistheAsoundlevelofunsteadynoisewithinaspecifiedtimeperiod,representedbyacontinuousandconstantAsoundlevelusingtheenergyaveragingmethod.LeqLpA（t）：噪聲信號瞬時A計權聲級(InstantaneousA-weightedsoundlevelofnoisesignal)，dBT：總測量時段(Totalmeasurementperiod)，s當測量時采樣測量，采樣時間間隔相同時，上式可簡化為：Whensamplingformeasurementandthesamplingtimeintervalisthesame,theaboveequationcanbesimplifiedas:LpAi：第一個A計權聲級(ThefirstA-weightedsoundlevel)，dBn：測量數據個數(Numberofmeasurementdata)晝夜等效聲級Ldn

為了考慮噪聲在夜間對人們煩惱的增加，規定在夜間測得的所有聲級加上10dB(A)作為修正值，再計算晝夜噪聲能量的加權平均，由此構成晝夜等效聲級這一評價量。Inordertoconsidertheincreasedannoyanceofnoiseonpeopleatnight,itisstipulatedtoadd10dB(A)toallsoundlevelsmeasuredatnightasacorrectionvalue,andthencalculatetheweightedaverageofdayandnightnoiseenergytoformtheevaluationquantityofLdn.LdnLd：晝間（06:00-22:00）測得的噪聲能量平均A聲級(TheaverageA-levelofnoiseenergymeasuredduringtheday)，dBLn：夜間（22:00-06:00）測得的噪聲能量平均A聲級(TheaverageA-levelofnoiseenergymeasuredduringthenight)，dB5累積百分聲級（統計聲級）CumulativePercentileSoundLevel(StatisticalSoundLevel)累積百分聲級StatisticalSoundLevel在評價區域環境噪聲和交通噪聲時，常用的是累積百分聲級，又稱統計聲級。Whenevaluatingregionalenvironmentalnoiseandtrafficnoise,thecommonlyusedmethodisCumulativePercentileSoundLevel,alsoknownasStatisticalSoundLevel.Lx表示在測量時間內高于L的聲級所占的時間為n%。LxrepresentsthetimeoccupiedbysoundlevelshigherthanLduringthemeasurementtime,whichisn%.相當于本底噪聲級EquivalenttobackgroundnoiselevelL90相當于中值噪聲級EquivalenttomediannoiselevelL50相當于峰值噪聲級EquivalenttopeaknoiselevelL10累積百分聲級一般只用于有較好正態分布的噪聲評價。StatisticalSoundLevelisgenerallyonlyusedfornoiseevaluationwithgoodnormaldistribution.6交通噪聲指數(TNI)TrafficNoiseIndex(TNI)交通噪聲指數TrafficNoiseIndex用統計聲級來評價機動車輛對周圍環境的干擾程度，是城市道路交通噪聲評價的一個重要參量。TNIusesstatisticalsoundleveltoevaluatethedegreeofinterferenceofmotorvehiclesonthesurroundingenvironment,whichisanimportantparameterforevaluatingurbanroadtrafficnoise.交通噪聲指數(TNI)的測量是在24h周期內進行大量的A聲級取樣，取樣時間不連續，將取樣后的聲級（如100個或200個）從大到小排列，求得累積百分聲級L10和L90。ThemeasurementofTNIinvolvestakingalargenumberofA-levelsamplesovera24-hourperiod,withdiscontinuoussamplingtimes.Thesampledsoundlevels(suchas100or200)arearrangedindescendingordertoobtainthecumulativepercentagesoundlevelsL10andL90.L10：峰值噪聲(peaking