[scenicrecords]

Does you hear it when you move the mouse or when the hard drive spins? I had that issue and it turned out to be a grounding problem. The ideal way to fix it is to work out grounding issues, but this can be a pain and expensive. If you have a simple setup, try using ground lifts on your powered speakers. It solved the issue for me. It's not recommended because you could get a shock without proper ground, but I have yet to have an issue. And I have an extremely low noise floor.