I've noticed on single player campaign, sometimes if the firefights get a little manic (ie a lot going on) the sound starts to break up really bad.
Pretty sure some frames are getting dropped as well.

Not many people must play this is surround sound 5.1 otherwise i think there would be allot of people talking about it... The sound is very glitchy in this game at times, although its meant to be kind of 'cartoony' if you get what i mean [not very good ] I dont like the gun sounds anyway, they sound clanky and not very different from eachother, and just not good quality, although it adds character to the game.
But I use 5.1 and when im flashbanged or knocked down or hit by a grenade or just being shot loads the gun sound comes out the center speaker as usual and at normal volume, but in these moments for a few seconds there is a delay of the gun sound form the center speaker in the 2 left and right speakers [when normally they are just be at the same time and volume as the centre {obviously}] and its extremly loud compared, I cant put the volume up too loud because otherwise when it happens its a big and sharp change in volume very quickly for a few seconds and i feel it could damage the expensive speakers.
And no its not my speaker system before you ask lol, its the game the sound is all round very glitchy, i must notice it way too much because im using surround sound, but this needs to be adressed.

I've experienced the same thing. In particular when I am using my PX21's.
I've also seen the frame rate drop too, but not until the sound glitching begins to get bad.

Yup noticed a bit of this while playing with my Astro headphones too

Im on 360, but got the same problem.

That all makes sense, as I'm using Tritton AX Pros.
I've not seen any options on the audio settings to change it to stereo or anything like that ... might see what I can do with the PS3 settings.

I have the some problem but I'm using the turtle beach headset. Idk if it's 5.1 dd tho. That also has happened to me in bfbc2, the sound gets all scratchy or is completely gone with faint scratches here and there.

I was playing in CCity and when I shot my gun it sounded like a helicopter. I kinda liked it.....