Description:
Audacity® is free, open source software for recording and editing sounds. It is available for Mac OS X, Microsoft Windows, GNU/Linux, and other operating systems.

You can use Audacity to:
Record live audio.
Convert tapes and records into digital recordings or CDs.
Edit Ogg Vorbis, MP3, WAV or AIFF sound files.
Cut, copy, splice or mix sounds together.
Change the speed or pitch of a recording