You may try this video converter, my friends recommend it to me. It can help you extract audio from MP4 or FLV video to mp3 or wma audio file, it's safe and works pretty well for me, I think it deserves for a try.
http://www.flvdvd.com/
Practice, lots of practice. Kidding… well, sort of… I was invited by Adobe to be a part of the Community Expert program after writing my book, actively participating in my local user group, maintaining an active blog and writing lots of Adobe-related articles. There’s more information here:
http://www.flvdvd.com/