The way it works is very simple: just add the files you want to convert to the list, choose the target format, and convert them.
It supports many different formats: AVI, FLV, MP4, MPG, MOV, RM, 3GP, WMV, and VOB, among others. As a target format, you can choose from MP3, AAC, AC3, WMA, FLAC, OGG, or WAV.
Besides choosing the format, you can change other parameters in the final file, too, like the bitrate, frequency, number of audio channels, and even the volume.
Free Audio Extractor is a quick and easy way to extract the sound from your favorite videos.