Goal: generate a white noise .wav fille of 1.5 hours
In matlab:
% create a matrix with random values:
>> noise = 2 * rand(90 * 60 * 44100, 2, 'double') - 1;
% write the wav file with a sample frequency o 44.1kHz
>> wavwrite(noise, 44100, 16, 'noise.wav');
This process takes a while and it consumes quite some of your system RAM.
More efficient, in bash:
$ dd if=/dev/urandom count=5400 bs=176400 | sox -s -c 2 -r 44100 -t raw -w - noise.wav
This took only 2 minutes!