Extracting WAV

What software can I use to extract wav audio from large avi, mpg files. I need to be able to view and hear video and audio to select start and cut off points for the audio extraction.

I think I used to be able to do this with virtual dub, extract as one large wav and then listen\select the audio selection from there. I can’t remember how to do this now and can’t see a way in VD…?

Any help appreciated.