endpointdetectionbandvariance.txt

频带方差端点检测的matlab源程序

clear all;   
clc;   
%基于频谱方差的语音端点检测   
N=256;%   
Winsiz=256;%帧长   
Shift=80;%帧移   
[x,Fs]=wavread('jnda1.wav');   
x=double(x);   
%对信号做预加重处理   
x=filter([1 -0.9375], 1, x);   
x=5*(x-mean(x));   
   
nseg=floor((length(x)-Winsiz)/Shift)+1;   
A=zeros(Winsiz/2,nseg);   
   
%下面循环是x信号的加窗处理并求出各点频谱能量   
for i=1:nseg   
    n1=(i-1)*Shift+1;n2=n1+(Winsiz-1);   
    xx=x(n1:n2);xx=xx.*hamming(Winsiz);   
    y=fft(xx,N);   
    y=y(1:Winsiz/2);   
    A(:,i)=abs(y);   
end   
%设阀值   
d=0;   
d=var(A(:,1))+eps;   
M=3*d;   
%利用频带进行端点检测   
D=zeros(nseg,1);D1=zeros(nseg,1);   
for i=1:nseg   
    D(i)=var(A(:,i))+eps;   
    if D(i)<=M   
        D1(i)=d/5;   
        else   
       D1(i)=2*D(i);    
          
    end   
end   
subplot(211),plot(x);   
   
subplot(212),plot(D1);