freq=[31 62 125 250 500 1000 2000 4000 8000 16000];
Fs=44100; %sample rate
time=10; %seconds per freq
N=16; %bitrate
t=linspace(0,time,Fs*time); %seconds at each sample
for(f=freq)
    aud=0.5*sin(f*t*2*pi());
    fn=strcat(num2str(f), '.wav');
    wavwrite(aud, Fs, N, fn);
end
