Maybe you know about these already but incase you haven't, here you go. You can play soothing sounds on your computer and if your computer is in your room, you can play them while you sleep. It is pretty cool, so if you want to try it out, here you go

http://sulger.net/soundsculptures/

The sounds run non-stop, so you don't have to worry about it shutting off. To shut it off, just close all browser windows.