thenoisysignalmagnitudespectrumXItissufficienttousethenoisysignalphasespectrumasanestimateofthecleanspeechphasespectrum,[]:XjNXSexpˆˆ()Theestimatedtime-domainspeechsignalisobtainedastheinverseFouriertransformofSˆ.Anotherwaytorecoveracleansignals(n)fromthenoisysignalx(n)usingthespectralsubtractionapproachisperformedbyassumingthatthereisantheestimateofthepowerspectrumofthenoisePv(ω),thatisobtainedbyaveragingovermultipleframesofaknownnoisesegment.Anestimateofthecleansignalshort-timesquaredmagnitudespectrumcanbeobtainedasfollow[]:otherwisevPXifvPXS,ˆ,ˆˆ()ItispossiblecombinethismagnitudespectrumestimatewiththemeasuredphaseandthengettheShortTimeFourierTransform(STFT)estimateasfollows:XjeSSˆˆ()Anoise-freesignalestimatecanthenbeobtainedwiththeinverseFouriertransform.ˆ()这个定义可以被纳入到维纳滤波方程如下：SNRH()维纳滤波器缺点是在所有频率固定频率响应和要求，估计功

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