Audacity is a free audio editor. You can record sounds, play sounds, import and
export WAV, AIFF, Ogg Vorbis, and MP3 files, and more. Use it to edit your
sounds using Cut, Copy and Paste (with unlimited Undo), mix tracks together, or
apply effects to your recordings. It also has a built-in amplitude envelope
editor, a customizable spectrogram mode and a frequency analysis window for
audio analysis applications. Built-in effects include Echo, Change Tempo, and
Noise Removal, and it also supports VST and LADSPA plug-in effects.
