Defonic - Create a unique sound environment at home or in the office
zenmix.io - Ambient background sound generator
Noizio - Feeling that the noise of the big city is too much for you to bear?
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.
SoundDrown - Ambient sounds to help you focus, relax, and escape
Soundescape - Generative 3D audio environments for focused work