I got these awesome headphones last week but have a small problem. They work fine in FS9, but in FSX, as soon as I load an aircraft, I get a sound like there is ai aircraft around. this happens when I when all engines are off. When I go into options sound and drop the engine sound down, this background noise also drops. At first I thought it was some kind of feedback as the phones are USB, but I unplugged my speakers. Sound still there. The background sound level is about the same volume as the normal engine sound.

Any ideas?