Question Noise problem in only one game!

[Warior Within]

Hi ... i have Creative Sound Blaster X-Fi Titanium Fatal1ty + audio Technica m30x headphone.... i really like it and it's ok...but recently a problem happened when i play call of duty modern warfare i hear a bit some kind of weak noise even with masater volume 0! and when i turn on master volume i hear another kind of heavy noise specially when someone speaks or when i hear explosion and ... only bullets have no noise! really weird !
I have this problem only in this game! Please help!