FYI if you run Mirror’s Edge on your PC and the sound effects are all outta whack, check to see if you have a Realtek sound card installed. Their older high definition drivers don’t work properly with the game, and you’ll have to download the latest version.
Now, chances are that your Realtek is built into your motherboard; that’s how they sell most of their gear. In most cases, you should install drivers for onboard devices — aka stuff built into the mother board, network card, sound card, etc — provided directly by your motherboard retailer. However this update is new this month, so chances are they haven’t picked it up. It’s also very likely that your mobo company doesn’t make changes to the sound card at all.
So, if your Realtek soundcard came in a computer provided by Dell, Gateway, HP, etc., check their update sites for an upgrade. If they do not have one, or if you built your own computer — good for you, great money-saver! — you can grab the latest version directly from Realtek (click the “Software” link, pass agree screen, and get the “Executable file” version).
Secondarily, I found reports that the K-Lite Codec Pack can cause the same behavior. I suggest you try the sound card first. If that doesn’t work, then try removing K-Lite.
Thirdly, if you haven’t heard of Mirror’s Edge or haven’t checked it out yet, I highly recommend that you do. Hard core FPS fans will get a refreshingly unique experience — you can beat the entire thing without firing a gun — and everyone else can pretend to be a free runner. Neat.