AoA Audio Extractor allows you to extract audio/sound or background music from video files. It supports extraction from AVI, MPEG, MPG, FLV (Flash Video), DAT, WMV, MOV, MP4, 3GP video files and exporting the audio as MP3, WAV and AC3 audio files. It can also be used to save any
portion of the audio of a video file.
http://www.aoamedia.com/audioextractor.htm