I do not have the solution for you, but suffice it to say the game in question you're talking about is circa 2001. I seriously doubt that the problem here is that the machine is too fast (well, it is fast for that game but that's not likely causing your sound issues).
I run games from the mid 1990s without the same problem. Every older game tends to have its issues, even when run on machines of their own time. There could be a patch for it, no clue. Just chiming in to say that I think trying to slow your comp down for it is probably moving in the wrong direction.