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本人觉得在阈值的处理上还有待加强，想和大家共同讨论！！！！ 
 
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clear 
clc 
%在噪声环境下语音信号的增强 
%语音信号为读入的声音文件 
%噪声为正态随机噪声 
sound=wavread('c12345.wav'); 
count1=length(sound); 
noise=0.05*randn(1,count1); 
for i=1:count1 
signal(i)=sound(i); 
end 
for i=1:count1 
y(i)=signal(i)+noise(i); 
end 
 
%在小波基'db3'下进行一维离散小波变换 
[coefs1,coefs2]=dwt(y,'db3'); %[低频 高频] 
 
count2=length(coefs1); 
count3=length(coefs2); 
 
energy1=sum((abs(coefs1)).^2); 
energy2=sum((abs(coefs2)).^2); 
energy3=energy1+energy2; 
 
for i=1:count2 
recoefs1(i)=coefs1(i)/energy3; 
end 
for i=1:count3 
recoefs2(i)=coefs2(i)/energy3; 
end 
 
%低频系数进行语音信号清浊音的判别 
zhen=160; 
count4=fix(count2/zhen); 
for i=1:count4 
n=160*(i-1)+1:160+160*(i-1); 
s=sound(n); 
w=hamming(160); 
sw=s.*w; 
a=aryule(sw,10); 
sw=filter(a,1,sw); 
sw=sw/sum(sw); 
r=xcorr(sw,'biased'); 
corr=max(r); 
%为清音（unvoice）时，输出为1；为浊音（voice）时，输出为0 
if corr>=0.8 
output1(i)=0; 
elseif corr<=0.1 
output1(i)=1; 
end 
end 
for i=1:count4 
n=160*(i-1)+1:160+160*(i-1); 
if output1(i)==1 
switch abs(recoefs1(i)) 
case abs(recoefs1(i))<=0.002 
recoefs1(i)=0; 
case abs(recoefs1(i))>0.002 & abs(recoefs1(i))<=0.003 
recoefs1(i)=sgn(recoefs1(i))*(0.003*abs(recoefs1(i))-0.000003)/0.002; 
otherwise recoefs1(i)=recoefs1(i); 
end 
elseif output1(i)==0 
recoefs1(i)=recoefs1(i); 
end 
end 
 
%对高频系数进行语音信号清浊音的判别 
count5=fix(count3/zhen); 
for i=1:count5 
n=160*(i-1)+1:160+160*(i-1); 
s=sound(n); 
w=hamming(160); 
sw=s.*w; 
a=aryule(sw,10); 
sw=filter(a,1,sw); 
sw=sw/sum(sw); 
r=xcorr(sw,'biased'); 
corr=max(r); 
%为清音（unvoice）时，输出为1；为浊音（voice）时，输出为0 
if corr>=0.8 
output2(i)=0; 
elseif corr<=0.1 
output2(i)=1; 
end 
end 
for i=1:count5 
n=160*(i-1)+1:160+160*(i-1); 
if output2(i)==1 
switch abs(recoefs2(i)) 
case abs(recoefs2(i))<=0.002 
recoefs2(i)=0; 
case abs(recoefs2(i))>0.002 & abs(recoefs2(i))<=0.003 
recoefs2(i)=sgn(recoefs2(i))*(0.003*abs(recoefs2(i))-0.000003)/0.002; 
otherwise recoefs2(i)=recoefs2(i); 
end 
elseif output2(i)==0 
recoefs2(i)=recoefs2(i); 
end 
end 
 
%在小波基'db3'下进行一维离散小波反变换  
output3=idwt(recoefs1, recoefs2,'db3'); 
 
%对输出信号抽样点值进行归一化处理 
maxdata=max(output3); 
output4=output3/maxdata; 
 
%读出带噪语音信号，存为'101.wav' 
wavwrite(y,5500,16,'c101');  
 
%读出处理后语音信号，存为'102.wav' 
wavwrite(output4,5500,16,'c102');