If pinknoise will suffice, then sox[1], (free, cross-platform, opensource), lets you generate your own (amongst many other things). The following will play for

If pinknoise will suffice, then sox[1], (free, cross-platform, opensource), lets you generate your own (amongst many other things). The following will play for 8 hours, but you can remove the time completely to run indefinitely: play -n synth 08:00:00 pinknoise [1]: http://sox.sf.net/ http://sox.sf.net/