[a,b]=wavread('24kfinparfait.wav');
c=1;
N=64;
star=330000;
stop=370000;
for k=star:N/32:stop
  tmp=abs(fft(a(k:k+N)));
  tabfft(:,c)=tmp(1:floor(length(tmp)/2));
  c=c+1;
end
imagesc(tabfft)