Spectro-Edit reads in regular PCM audio files (currently, only 16-bit mono WAV is supported), then shows you the audio visually in a time vs. frequency plot. The fun part is, you can "paint out" any part of the visualization and play back the audio subject to your modifications. When you are happy with the result, you can save your work back to a WAV file. This could be useful for podcasting (edit out microphone noise, chair squeaks, phones ringing, and other background noise), music (make strange and unusual modifications to the sound for artistic reasons), research (visualize animal calls or noise pollution from nearby industrial activity), and general purpose geekery (which is why I made it).