And also fool around in the options menu. There should be a box to check "EAX" I believe, or something close to that. try turning it off and see if it works.
go to programs folder there should be a folder caled directx go in there and click on the program called dxdiag for directx diagnosis or whatever. after it loads click on sound device tab and it should display sound card info
Try getting the latest sound drivers for your PC. Most of the time this would fix issues you would have with the game if this is the only program that is not working properly for sound.