As the name suggests, this is a simple program for editing sounds. You wouldn't want to record an album with it, but you can add layers to your sound piece, fade bits in and out, apply some filters, and most importantly, record with it (as long as you have a microphone.)

Perfect for creating and editing your Flash movie sounds.

Sound Edit is Macintosh Software. There are several PC freeware versions that come and go. You are looking for a stereo sound recording software with basic editing capabilities. It should be able to save files as <.aif> and <.wav>. You might have to pay to get one that converts a sound file to <.mp3>.