1 简介
语音信号在实际场合中通常容易受噪声的干扰,较强的噪声会降低语音识别的效率,为了使语音信号可懂,需要对噪声进行处理.本文先分析了语音和噪声的特性,介绍了谱减法、最小均方和维纳滤波三种语音去噪算法,以及这些算法实现的仿真结果对比。
2 部分代码
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=musicalif nargin<3 po=[0.04 0.1 0.032 1.5 0.08 400 4 4 1.5 0.02 4].'; else po=p; endns=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:nfidx=(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 immb(:,1)=min(mb(:,1),pxn);elsemb=[pxn,mb(:,1:po(7)-1)];endpn=po(9)*min(mb,[],2);%os= oversubtraction factoros=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);endif nargout==0soundsc([s; ss],fs);end
3 仿真结果



4 参考文献
[1]吴马军, 俞兴莉, 陈亮. 语音降噪算法的实现研究[J]. 信息通信, 2019, 000(001):72-74.
博主简介:擅长智能优化算法、神经网络预测、信号处理、元胞自动机、图像处理、路径规划、无人机等多种领域的Matlab仿真,相关matlab代码问题可私信交流。
部分理论引用网络文献,若有侵权联系博主删除。
本文探讨了语音信号在噪声环境下的处理问题,重点介绍了谱减法、最小均方和维纳滤波三种语音去噪算法,并提供了Matlab实现的详细代码。通过仿真结果对比,展示了不同算法在语音增强方面的效果。
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