This process solved the static/hissing problem on the audio output of my Asus P6T using the Realtek driver. This problem can be solved by making a quick change within the Realtek driver:
1. Click on Start -> Control Panel
1. Open the Sound.
2. Double click the Speakers selection.
3. Click on the Levels tab.
4. Find the PC Beep. Mute this by clicking on the blue speaker icon to the left of the Balance icon.