Sounds of Earth - Listen to relaxing ambient sounds of nature
Noisli - Noisli is a fantastic background noise and color generator for working and relaxing. Online soothing ambient sounds like White noise, Rain and Coffee Shop.
Noizer - Ambient sounds like Noisli, but free
A Soft Murmur - Ambient sounds to wash away distraction.
Noizio - Feeling that the noise of the big city is too much for you to bear?
SoundDrown - Ambient sounds to help you focus, relax, and escape