I think I'm getting the same thing. Every once in a while out of no where, for no rhyme or reason, my volume would screech LOUDLY. I wouldn't be able to hear anything else. I use TB headset and tv for sound. It would happen just for a few seconds to just over a minute. Once I can hear people talking on mics, I know it's over and can turn my volume back up. I just assumed that it was my PS3, I bought it used, but now from this post I could safely say, it's not.

This crap already blew up my Turtle Beaches, and almost screwed up my Tritons, not to mention gave me a 3 day ring.  both times.

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"The Second Amendment: America's original Homeland Security"

I have experienced this once, and I have been in a match with someone else that has experienced it. It's a very loud static/screeching noise that doesn't seem to be controlled in any way by the game volume. It's not chat related either, as I turned the chat volume on my headset all the way down and still had the noise. It near blew out my eardrums and I had to tear my headset off to keep from going deaf.

I don't know if they addressed it in the new patch. Like I said, my experience is that it is rare, and no clue what causes it.

I have ran into this issue in MW2, Blk ops, and now MW3. at first i though my friends PS3 was going to explode. i bought a PS3 3 days ago and ran into this issue 2 times now.

The sound is simular to what you would hear if you wired up a subwoofer up to a wall outlet. we all need to submit a report to activision about this bug, it has been around way too much and have even cost some people damage to their audio gear. i do think it screwed up my turtle beach headset, it now has a rattle in the left speaker.

just for clairification, this is NOT a audio feedback loop from someones mic, It is a bug with the software

and here is a video http://www.youtube.com/watch?v=BstrSZBqS1E the sound starts at around 0:07 there are a few other videos that show this issue as well. and if you run into this issue while playing online no one else but you will hear it, it doesnt happen to everyones system at the same time. also notice how no one is talking or has talked in that video, so that rules out a Mic audio feedback loop.Once the sound has stopped notice how he has no in game sound, it either will correct itself and you will have in game sound or it will be like this and will have no in game sound for the rest of the game.

Again please submit a bug report to activision, they are not likely to read these boards.

That's it!
Damn that sound!!!!!!!