celil, freecorder 4 will extract the audio then/than permit you to dissect and edit it in your favorite audio editor such as pg's ptpa (power tracks pro audio) or audacity (free).

http://www.applian.com/freecorder5/

http://audacity.sourceforge.net/download/

be aware that any audio editing may affect the sync with the video, of course.

a great resource is: www.videohelp.com where you will find programs that allow both audio AND video editing in one application.