Matlab音频语音信号增强处理

function [ss,po]=specsubm(s,fs,p) %SPECSUBM performs speech enhancement using spectral subtraction [SS,PO]=(S,FS,P) % % implementation of spectral subtraction algorithm by R Martin (rather slow) % algorithm parameters: t* in seconds, f* in Hz, k* dimensionless % 1: tg = smoothing time constant for signal power estimate (0.04): high=reverberant, low=musical % 2: ta = smoothing time constant for signal power estimate % used in noise estimation (0.1) % 3: tw = fft window length (will be rounded up to 2^nw samples) % 4: tm = length of minimum filter (1.5): high=slow response to noise increase, low=distortion % 5: to = time constant for oversubtraction factor (0.08) % 6: fo = oversubtraction corner frequency (800): high=distortion, low=musical % 7: km = number of minimisation buffers to use (4): high=waste memory, low=noise modulation % 8: ks = oversampling constant (4) % 9: kn = noise estimate compensation (1.5) % 10:kf = subtraction floor (0.02): high=noisy, low=musical % 11:ko = oversubtraction scale factor (4): high=distortion, low=musical if nargin<3 po=[0.04 0.1 0.032 1.5 0.08 400 4 4 1.5 0.02 4].'; else po=p; end ns=length(s); ts=1/fs; ss=zeros(ns,1); ni=pow2(nextpow2(fs*po(3)/po(8))); ti=ni/fs; nw=ni*po(8); nf=1+floor((ns-nw)/ni); nm=ceil(fs*po(4)/(ni*po(7))); win=0.5*hamming(nw+1)/1.08;win(end)=[]; zg=exp(-ti/po(1)); za=exp(-ti/po(2)); zo=exp(-ti/po(5)); px=zeros(1+nw/2,1); pxn=px; os=px; mb=ones(1+nw/2,po(7))*nw/2; im=0; osf=po(11)*(1+(0:nw/2).'*fs/(nw*po(6))).^(-1); imidx=[13 21]'; x2im=zeros(length(imidx),nf); osim=x2im; pnim=x2im; pxnim=x2im; qim=x2im; for is=1:nf idx=(1:nw)+(is-1)*ni; x=rfft(s(idx).*win); x2=x.*conj(x); pxn=za*pxn+(1-za)*x2; im=rem(im+1,nm); if im mb(:,1)=min(mb(:,1),pxn); else mb=[pxn,mb(:,1:po(7)-1)]; end pn=po(9)*min(mb,[],2); %os= oversubtraction factor os=zo*os+(1-zo)*(1+osf.*pn./(pn+pxn)); px=zg*px+(1-zg)*x2; q=max(po(10)*sqrt(pn./x2),1-sqrt(os.*pn./px)); ss(idx)=ss(idx)+irfft(x.*q); end if nargout==0 soundsc([s; ss],fs); end