It depends on how the DVD was encoded. Normally, the audio either compressed into the MPEG or on a separate 12 bit or 16 bit track. Some even record to 5.1 dolby (newer sony) of compressed HD (two kinds, HDV, AVCHD) Take the DVD camera, or video camera, and then figure out all the settings used to record. If you are in 12 bit audio you will need to convert the audio, and so on.
DVDDecrypter is probably the most accurate DVD extractor for non copyright DVD. But I'm assuming this is a format/codec issue. Normally, you should not use the built in camera sound except as a scrub track, but it can be made to sounds presentable. Most DVD NLEs do not handle audio properly, so that is another hurdle. NLES that do are MAGIX (cheap) Sequoia (very expensive) and Vegas (medium) dt -- To get on or off this list see list information at http://www.cs.dartmouth.edu/~wbc/lute-admin/index.html
