I freaked my girlfriend out once because I had my (desktop, a large tower!) computer connected to my stereo. I had left for some reason and there was no music p

I freaked my girlfriend out once because I had my (desktop, a large tower!) computer connected to my stereo. I had left for some reason and there was no music playing, but ICQ would play a little knocking sound when someone logged in. She had heard it three times from the living room, scanned every door and window to find out who was knocking :-)