http://www.soundsleeping.com/

Literal (How to Use The Sounds in this website):
The free relaxing music and nature sounds on this website have been carefully chosen for their ability to aid sleep, reduce stress, and provide a relaxing atmosphere for activities such as yoga, tai-chi, and meditation.

* Rhythmic drumming creates a hypnotic effect to help induce sleep
* The sound of the vibraphone is calming, and may reduce stress
* Rain acts as a white noise machine that masks household noises such as refrigerators, heaters, and creaking floors
* The booming sound of thunder helps to mask loud stereos, barking dogs, and traffic
* The sound of steady, rhytmic ocean waves provide a sensation of relaxation and calm.
* Birds and windchimes are comforting sounds that provide a relaxing and stress free atmosphere
* An atmosphere of rain and thunder may be especially relaxing, because one feels they cannot go out to work
* Ocean waves may remind one of a relaxing and calm vacation