Moszen - Moszen is a free web service that provides ambient sounds from natural environments to help you relax and avoid stress in your daily life.
Brain.fm - Music designed for the brain to enhance focus, relaxation, meditation, naps and sleep within 10 - 15 minutes of use.
Noizio - Feeling that the noise of the big city is too much for you to bear?
MyNoise - Custom shaped online noise machines. Many Many generic sounds
Sleep Bug - Sleep Bug is the name of an ambient sound mixer that generates a wide range of scenes and music using the random sound effects.
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.