Black Ops 2 Very Weird Sound?

I was just playing some multiplayer with my headset on and i hear this weird noise that sounds like something out of transformers. I left the lobby because i thought that someone was messing around with the sound and i start a new game. Im in the lobby waiting for the game to start and when it does start the noise starts back up again. I can hear other people talking on their mics but other than that just the noise. I cant hear any of the gameplay noises either. Any fix???