SoundTouch is an open-source audio processing library that allows changing the sound tempo, pitch and playback rate parameters independently from each other, i.e.:
Sound tempo can be incresed or decreased while maintaining the original pitch
Sound pitch can be incresed or decreased while maintaining the original tempo
Change playback rate that affects both tempo and pitch at the same time
Note: The above URL is a relay address that will forward the browser to the actual server. If you'll create a link to SoundTouch library page, please use the above URL instead of the actual address, so that the correct link address will be maintained although the pages would move to another server.
* soundtouch.dll was created by DSPguru. source-code, under Lesser GNU Public License, can be obtained from http://DSPguru.doom9.org