I had it happen twice. Since the game doesn't use much bandwidth, I run skype in the background so my hotspot connection keeps me prioritized. The two times I didn't have it running, the sound cut off during single player quests. Never had it happen on anyone else's wifi or any other time so far.
I'm having a similar issue now. Audio is fine at login, but when I get to a lobby it not only does my in game sound stutter but it also makes every other audio source on my PC cut in and out about every 3 seconds, even my microphone.