clc
clear

[xfsbits]=wavread（‘liuxiaonan.wav‘2048）;%音頻信號
x1=reshape（x14096）;
sound（x1fsbits）;
y1=fft（x1）;
N=length（x1）;
t=（1:N）/fs;
figure（1）
plot（tx1）;
title（‘原聲音信號的時域波形‘）;
xlabel（‘時間/t‘）;
ylabel（‘振幅/A‘）;
grid;

M=nextpow2（x1）;??????????????????????????%?求x的長度對應的2的最低冪次m?
N=2.^M;
if?length（x1）????x1=[x1zeros（1N-length（x1））];????????????%?若x的長度不是2的冪，補零到2的整數冪?
end?
NV2=N/2;
NM1=N-1;
I=0;
J=0;
while?I????if?I????????T=x1（J+1）;
????????x1（J+1）=x1（I+1）;
????????x1（I+1）=T;
????end
????K=NV2;?
????while?K<=J
????????J=J-K;
????????K=K/2;
????end
????J=J+K;
????I=I+1;
end???????????????
%x1;?
y=x1;??????????????????????????????%?將x倒序排列作為y的初始值?
WN=exp（-i.*2.*pi./N）;??????????????????%蝶形運算?????
for?L=1:M
????B=2^L/2;???????????????????