Exactly same thing here with my brand new Logitech G930 Wireless.
It happens mostly when firing full auto and firing aircraft rockets/cannon, and when projectiles hit the ground the sound become very distorted and start skipping until the impact effect is gone. It happens with loud explosions as well and sometimes inside jets cockpits because of the engine sound.

-The problem occurs using the 7.1 surround, we can say it almost disappear switching to stereo mode but you can still hear a bit of distortion even on stereo.

This issue does NOT HAPPENS with ArmA II, or any other game.
I did a test making a mess of sound effects, burst firings, explosions and so on with all games i could try (including A2:CO, Hitman Absolution, APB, Shadow Warrior 2013, BF3, Skyrim, Tomb Raider 2013, GRID 2, and many others) just to check if my headset is defective but guess what, the surround works flawlessly with all those games. Not a single distortion or skip.

This is not a minor glitch, is a major sound issue from my point of view. All pro gamers use a headset, a lot of "normal" gamers use it as well, I bet -at least- half of them use surround and will experience the horrible distortion.
I can't believe theres nobody at BI which play/test A3 with a surround headset and says WTF when hearing some big explosion or a pair of soldiers shooting bursts.
PLEASE fix this, A3 is the top you guys can't ignore a serious flaw like this one.

System: Win7 Pro 64bit | OnBoard SoundCard (Asrock MB)