Only sound in a game that's ever scared me was playing the original Medal of Honour.. When you're crawling around the air vents.. and you hear a "tick.. tick.. tick.." of a German with an MP40 crawling around too, and you don't know which end he's going to arrive, and if you guess wrong you get an ass-full of the Omni-gun SMG rounds that all SMGs can use... ARGH!!!
Sorry.
I did love that game, and MOH: Underground. Probably because they were the first FPS's I'd ever played outside of an arcade, and had nothing to compare it to.. And they had a halfway decent story, unlike the newer MOH installments.