The music is a decent rock soundtrack. For the most part, however, it was repetitive and intrusive during gameplay. It didn't help that the music always starts playing when you start fighting. I found I had to turn the volume down on the background music to be able to concentrate.
As for sound effects and ambient noise, I wasn't too impressed. Sure, the sound effects themselves are fine: gun blasts, fire, and enemy speech are all of good quality. The problem is in how they are used. I could hear a person yelling "Show yourself!" through a brick wall as if he were standing right next to me. I was also thinking at first that I was supposed to be listening to the enemies' comments in order to determine how I should plan my next move. Alas, it seems they will shout something like, "Go, and check it out!" all day long, but only rarely will one of them "go and check it out." No, they will be on the same alert level no matter what they say they plan to do. In general, the only way the sound effects helped you was by telling you that "Hey, someone is standing near you."