This seems to be a recent thing for my game. I've lately noticed that after performing an action sometimes the sound of that action repeats for the rest of the game, or at least until that unit is dead (I think). I noticed it just once after hours and hours of gameplay, but then I decided to start a brand-new, no mod game and it is occurring all the time now. I think it might be because I play windowed instead of full-screen, as I did not notice it when it was the latter, but that might just be coincidence. Any idea? I did a search for this, but I think the description might be too ambiguous to allow for precise results.