When you updated your drivers, did you uninstall the old drivers and then clean them using drivercleaner? it's a free program, that you run after uninstalling your sound and video drivers. if you didn't you might try deleting the drivers, cleaning them (best way to ensure it cleaned ALL the old drivers files is to run driver cleaner in safe mode) If that doesn't fix it, assuming you aren't using onboard sound you might try putting your soundcard in a different slot. But before you do that, make sure you uninstall the drivers first (clean it out)
Turn your PC off and put it into a different PCI slot. If that doesn't do it, if you have anything overclocked be it cpu or video card let it run at stock speed. if you have onboard sound, and are using a PCI sound card make sure your onboard sound is disabled in the bios. Other than that, only thing I can think of is your video card or sound card might be on the fritz. If you have anything else plugged in PCI wise, might try taking it out leaving it out and see what happens.
