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.
Noizio - Feeling that the noise of the big city is too much for you to bear?
Noises Online - Premium masking sounds
SoliCall Pro - Removes noise & echo from any VoIP call. Can also be used for call recording.
A Soft Murmur - Ambient sounds to wash away distraction.
Calmsound - Calmsound bring the giant collection of the finest natural sounds that are ideal for multiple purposes like keeping the brain calm, sleeping smoothly, getting relaxed and helpful for tinnitus sufferers as well.