how can i write my demodualted voice signal to a file

For AM modulation i gave my voice as input.i am able to observe my demodulated signal in frequency spectrum but i want to listen the demodulated signal ...so how can i listen the demodulated signal ?

[David K.]

I assume that to initially get to the frequency spectrum you used the fft. To listen to it you need to convert back to the time domain with the inverse fft.

X = ifft(Y,n)

Then, if you want to listen with matlab you can use

sound(X, Fs);

where Fs is the sampling frequency of your song.

You could also export it if you want to listen outside of matlab

filename = 'song.wav';
audiowrite(filename,X,Fs);