What are you using for sound? Onboard, an installed expansion card, or a usb model? Once Vista is out you would have to go to the manufacturer's site for the Vista compatable updates found there. At this time the only drivers for Vista are in beta form at the present. Once it has been out for a good period of time the updated drivers should take care of that.
Meanwhile one report by Symantec warns of a security loop hole seen in Vista that's not present in XP. You may be glad to wait for any upgrade to Vista until the security fixes start coming out.
http://www.pcmag.com/article2/0,1895,1990931,00.asp