室內(nèi)聲學(xué)測量中聲源性能的研究以及揚聲器響應(yīng)影響的消除.pdf

1、同濟大學(xué)聲學(xué)研究所碩士學(xué)位論文室內(nèi)聲學(xué)測量中聲源性能的研究以及揚聲器響應(yīng)影響的消除姓名：趙躍英申請學(xué)位級別：碩士專業(yè)：室內(nèi)聲學(xué)指導(dǎo)教師：盛勝我20030225ABSTRACTTheroomacousticalparametersareobjectiveparametersButtheprecisionoftheresultsofthemeasurementsarelimitedbythewavelengthofthesound，part

2、icularlyinlowfequencybandsTheresultsofthemeasurementsareinfluencedbymanyfactorsandtheimportantoneamongthemiSthesoundsourceThesoundusedinourmodemmeasurementismadebyaloudspeakerfedbythedigitalsignalemittedfromacomputerThed

3、igitalsignalcallbepseudorandomwhitenoise，sinesweep，speciallyshapedtoneburstwhichalerepeatableandwithhighsignaltO‘noiseratiosButthesoundmustbeaffectedbytheresponseoftheloudspeakerSOtheresultisnottheimpulseresponseofdeltaf

4、unctionbuttheimpulseresponseofwavepacketTheresultshaveshownthattheeffectsoftheresponseoftheloudspeakerarenotsignificanttothetimemeasurementofearly—arrivingreflectorsorthereverberationtimemeasurementintheroomswhichreverbe

5、rationarelongenoughThenotableeffectsarefoundinthemeasurementofotheracousticalparameters，particularlytheparameterswhicharesensitivetOthetime，suchasearlyto—latearrivingsoundenergyratioBecauseoftheresponseoftheloudspeakerth

6、ereisinterferencebetweentwowavepacketsandthedistortionoftheirrelativeenergyHence，notonlytheresultsofroomacousticalparametersbutalsotheotheracousticalparameterssuchasabsorbingcoefficients，reflectingcoefficientsCanbeaffect

7、edInthispapertherespondofloudspeakeranditsinfluencetotheacousticalparametersarestudiedAndthemethodofthecorrectoftheresultsbasedonthegeneralcorrelationmeasurementandtheroomimpulseresponseisdescribedTheresultafterdeconvolu

8、tionusingthedirectwavepacketoftheroomimpulseresponseismoreclosetotheimpulseresponseofdeltafunctionSothedifferencesusingdifferentinstrumentsofsourcecanbedecreasedandtheobjectiveoftheroomcanbedescribedItisprovedbythecalcul

9、ationandexperimentinthispaperthatthemethodisreasonableintheoryandavailableinpracticeInaddition，thismethodCanhefurtherappliedtOotheracousticalmeaSUrenlentSKeywordsroomacousticalparameter；soundsouse；responseofloudspeakerro