y = wavread('think.wav'); length(y);

L=2^16;
j=zeros(1,(L/2+1000));
n=[0:(L/2+1000),j];
x=.4*sin(n/2)';

x=x+y(1:2000+L+1,1);
wavplay(x,44000)
zp=zeros(L,1);
xp=[x(1:L/2); zp; x(L/2+1:L)];
X=fft(xp);
colormap(hot)
%imagesc(abs(Xtwz));

subplot(211);plot(x);
subplot(212);plot(abs(X(1:L)));