I hear a high-pitched tune when i move my mouse

Topic says it. I have a dell beam mouse. I hear a very soft high piched light when i move my mouse. I dnt think the sound comes from the mouse itself, but from my PC!! plz help,
Answer #1
you have onboard sound ?
Answer #2
sorry??
Answer #3
start here

http://www.infopackets.com/channels/en/windows/gazette/2003/20030529_sound_card_distortion_while_scrolling_mouse.htm
http://www.infopackets.com/channels/en/windows/gazette/2005/20050816_integrated_onboard_sound_versus_dedicated_soundcard.htm