This is a step-by-step process that takes you through what your problem(s) may be. It helped me find out that BioShock wouldn't run due to OpenAL being installed by my soundcard.
If you can run the game with "-nosound" as a launch setting, then clearly your problem is the soundcard. If not, try "-dx9"
If none of the above work, stop reading this topic and click on the link and read that guy's topic.
I just went into sound options and enabled the device "Stereo Mix" in recording and it made my sound work.
On a magical DERP, I fly awaaaay into the rainbows
I don't have a Realtek or whatever it is card, so I don't have a Stereo Mix option