% signal delay estimates using Cross-correlation function
function [x1,x2,y,ytime,k]=yanshi(wavfile,time)
% sound 读入WAV文件 k为理想延时
k=time;
[sound,Fs] = wavread(wavfile);
s=sound(:,1)';
mad=sum(abs(s))/length(s);
r=randn(1,length(s)*2); %noise
r1=r(1:length(s));
r2=r(length(s)+1:length(s)*2);
d=zeros(1,k); %the delay of the signal
x1=s+r1;
x=s+r2;
x2=[mad.*randn(1,k) x(1:length(s)-k)] ; %delay signal
y=xcorr(x2,x1); %Cross-correlation of the signal from-130 to 130
ytime=find(y==max(y))-length(s); %延迟