I’m noticing this after a bunch of games in a row - it seems like part of either a tractor beam or emp sound is getting softly looped over and over long after it has expired, continuing into the menus and even other games.
I’m not sure which of those it is, but it eventually piles on to the point where it’s an extremely annoying drone.
Edit: I suppose this sort of thing could get really hardware related. I’ve got some sort of realtek sound onboard an Asus motherboard - I don’t know much else about it.
WinXP, pitch shift off.