Audio Problem: Need Help Asap

When I play my game all I hear are the crowds and sfx but i can't hear the commentator. I read it somewhere that this is a possible result of a ripped game but mine is not and I have a cd. And again I read it somewhere that in order to fix this is that I need to extract the audio files from the cd but the problem is when I extracted the audio and replaces it to the existing one, it still doesn't work so my question is:

How can I extract the audio from the cd?
Where to put it?

Thanks

So your game is an original copy?

I dunno. I bought the cd from the mall.