Humming Sound when moving around on Desktop from Speakers????

[Almas]

I didn't really notice this till it was silent in my office but when I listened whenever I moused over the Dock or I moved the cursor to a hot spot or clicked any menu for that matter I can hear a faint short hum from my speakers now it's nothing severe but it's a slight hum as if you hummed in the back of your throat softly. Has anyone else noticed this strangeness? I am using the AC97 Apple Drivers. Hopefully I'm not crazy :P