ArmA 3's helicopters are so loud, they drown out ACRE radios too, unless you turn the radios up substantially in Teamspeak. As an example, the team I play on were standing on the tarmac a few nights ago getting ready for an op, when a helo was powering up, some 200 meters or more away. As this bird was powering up and then sitting stationary on the tarmac waiting for us, quite a few of us could NOT hear our radios, because the helo was drowning them out. Raising/lowering headset in ACRE didn't help. I had to turn ACRE up in TS to be able to hear over the helo, and keep in mind that helo was sitting a good 200 meters away.
I realize that in real life, helos are extremely loud; Chinooks and Blackhawks fly over my house all the time, sometimes so low I can see the facial expressions of the soldiers riding therein if they come over during the day. The Chinooks, especially, shake everything. But even when they're directly overhead, one can still hear and talk just fine. It's not like when F-16's fly over and you can hear nothing but the roar of the engines.