Just recently, ie the last day, I've started to get a bad distortion/echo effect on my ingame sounds. It sounds like everything I do, from firing guns, shutting engine off, to flaps deploying, is in a cave.
This oddly coincides with me deleting my Aces High II/sounds_c folder, which I was just using to backup other sound files, and I thought would have nothing to do with the game (I figured the game was only reading the Aces High II/sounds folder). Does this deletion of the sounds_c folder have anything to do with the echo? If not, what could be the cause?