% noisespeech.m

[y, fs, bits] = wavread('speech.wav');

y = y/max(abs(y));

sound(y,fs);

disp('Paused ... hit any key');
pause

noiseScale = 0.8;

n = rand(size(y));
n = (n-0.5)*2*noiseScale;

y = (y + n)/2;

sound(y,fs);