Having odd noise in my headset

It's not a proper sound card issue as such, as it is an onboard sound card issue, but it didn't really fit in elsewhere.

Anyway, I'm having this weird sort of high pitched 'scraping' sound in my headset. It's not a headset issue, as the problem persists regardless of headsets. My motherboard is an Asus P5K-E/WIFI-AP, P35, Socket-775 and I am on Windows 7. The problem also persisted across Windows versions and driver updates.

What is odd about this high-pitched, scraping sound, is that it often follows my movement if I play a computer game. When I tilt the view to the left or right, up or down, the sound will be affected from it, and change pitch. It also reacts to scrolling down in a browser.

I've endured this for a long time, but it's starting to drive me crazy. I have tried to update the drivers, but to no avail.

Does anyone know what may cause this? I'd buy you a muffin and a cup of coffee if you could help me.