WaveSong

WaveSong is a nature-sound generator program for Windows, using your sound card digital, real nature sound clips, and clever processing techniques to produce a sustained nature audio environment.

This program could be used to mask out unwanted ambient noise and promote relaxation and concentration. Controls for Volume and Tempo allow the listener to tailor sound output to individual preferences.
WaveSong now has a built-in timer, tray icon capability, and screen-saver support.