function midfilter()
wavesource=wavread('D:\mymusic\22.wav');%讀取語音信號
wl=length(wavesource);
ml=5000;    %設定截取語音信號的長度
nl=21;  %滑動窗口的長度
waves=wavesource(fix(wl/2)-ml/2+1:fix(wl/2)+ml/2,2);%截取語音信號
waveanoise=waves;
noise=max(waveanoise);
waveanoise(500,1)=waveanoise(500,1)+noise;%疊加了噪聲
waveanoise(1000,1)=waveanoise(500,1)+noise;%疊加了噪聲
[wavend]=midfiltering(waveanoise,nl);%中值濾波
subplot(3,1,1)
plot(waves);%畫出語音信號的波形
title('畫出語音信號的波形');
subplot(3,1,2)
plot(waveanoise);%畫出疊加了噪聲的語音信號的波形
title('畫出疊加了噪聲的語音信號的波形');
subplot(3,1,3)
plot(wavend);%畫出中值濾波后的語音信號的波形
title('畫出中值濾波后的語音信號的波形');