matlab小波去噪

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);