Scharping reduces the noise of the CD-Drive, while listening to Audio-CDs by lowering its speed. Scharping is a small Mac OS X program running in the background waiting for an Audio-CD to be inserted. As soon as this happens, a small dialog gets displayed requesting the desired speed of the drive. At the moment the playback of the CD begins Scharping instantly reduces the speed of the CD-Drive so that almost all of the drive‘s noise gets eliminated. The lower speed has no negative impact on sound quality. Far from it! Because of the noise reduction, quality gets increased and listening to CDs on your Mac is fun again.
http://www.aquarius-software.de/AQUARIUS-software_en/Scharping.html