[Benjo]

I agree. I've had better results listening to white noise.

[TeMPOraL]

White noise hurt my ears, but I found pink noise working great and not disturbing. I could listen to it for an hour; at one point my imagination starts treating it as a sound of sea waves on a beach.

[Benjo]

Yes, I like nature sounding noises like beach or wind.

http://simplynoise.com/ has decent brown noise.