I've been having this problem for a while now in Battlefield 1942. I get some static sometimes, and then all of the sudden the sound just stops and I get a loud shreaking sound which doesn't go away until I close BF1942. I'm using a Hurricane Extreme soundcard (at least until I buy a newer card).
There is a new patch just out, v1.31, that among other things has some sound improvements and fixes. If you don't have it yet, maybe it will help.
Hmm.. now I just need to wait for my BF1942 cd to get back from EA. I cracked it, lol, had to get a replacement.
I had some of these problems too, but its been so long since i have played that game. I believe many people had those problems. First i would try going to the battlefield 1942 homepage, and search their forums for the problem. I believe it had something to do with a sound option you could turn on and off in game. However, i thought that these problems only related to Creative cards, so i'm not sure....
Well, it's not doing it anywhere.. although I do get a little bit of static when the intro screen comes up and sometimes when loud explosions happen still.. not enough to really bother me though.