which audio are u talking about...to activate the front audio panel of your cabinet or to activate your onboard audio?
to activate the onboard audio...just go to bios and eable it from there (it should be enabled by default)
and to activate the front audio panel...u need to plug in the 9 pin female socket (which u'll find somewhere inside ur cabinet) to the front panel audio male connector in your mobo (refer to ur mobo manual...u'll find it there)