I've got a Plantronics GameCom 780 USB headset, which I use when playing Arma 3. Frequently, I'll hear the Windows 'device connected' or 'device disconnected' (not sure which) sound, and I'll lose all sound in Arma 3 until I close the game and restart it again.
This has never happened with any other game (but I've never played Arma 2). However, it happens more frequently when I'm also running TeamSpeak. In that case, in addition to losing all sound in Arma 3, I'll also lose my microphone in TeamSpeak. For some reason, I'll still be able to hear everyone in TeamSpeak, but they won't be able to hear me, until I close TeamSpeak and restart it.
This has happened for months, since I first got Arma 3 alpha. And it would happen, occasionally, whether or not I was running TeamSpeak as well. But it was always rare until the beta version of Arma 3 was released. Then it started happening four or five times a night (one time, four times in the first 20 minutes!).
If I don't run TeamSpeak, it happens less often, but still a couple of times a night, on average. (It's hard to tell, because I often quit playing when this happens, or else I just continue playing Arma 3 without sound - which is pretty much impossible, since I can't even tell if I'm taking fire.)
I've checked all my drivers. I've completely removed the Plantronics software and reinstalled it. I've tried different USB ports. I've posted questions on forums (the Arma 3 forum, the TeamSpeak forum, and the Plantronics forums) and found just one other guy with the exact same problem. (He hasn't found a solution, either.)
Note that I don't have another headset to try, and I don't know any other people who play Arma 3 - or play any other computer games, for that matter. (I'm 62, so I'm a little outside of that age group, I guess.)
I could put up with the annoyance of this at first, but since Arma 3 beta was released, the game has become pretty much impossible to play - at least, in multiplayer. (Since I don't need a microphone, I can still play single-player without the headset - just using my computer speakers, instead.)