Audacity is an audio recording and editing software package for various operating systems.  The Linux version is available from repositories and can be installed from the software manager or terminal of most Linux distros.

This a brief overview and I am not an expert in the program.  You can find more information directly from their website:
http://www.audacityteam.org/

Read my post on this topic:
http://switchedtolinux.com/software/audacity/

See more software overviews:
http://switchedtolinux.com/software/

Switched to Linux is not affiliated with or compensated by Audacity