I've had that happen.. Last night was the worst too. The sound suddenly went really low, and even after the round was over it stayed low. I thought it was my TV until I read this thread to see others have it happen to them too.
Also, my TV will randomly make a high pitch beep noise that wont stop. Kinda like the noise when you throw flashbangs and stuff, but louder, and it wont stop until I turn the TV off. I doubt it's the game causing it though, 'cause I've had it happen while playing MGS3 too.
