ROOM - A Personal Space for The Open Office
Noizio - Feeling that the noise of the big city is too much for you to bear?
Hear - Hear is a sound enhancement application for the Mac.
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.
Krisp - Mute the background noise during your calls
A Soft Murmur - Ambient sounds to wash away distraction.