As title says, I completely lost sound, Nothing… Kinda hard to play like that!! 
If you have the time, head over to this thread and post your DxDiag and, if possible, some video footage when it happens to help the devs pinpoint the issue:
Oof, I’ll record if I pick up the map again tonight. thanks for this info
Keeps happening to me.
Always after a death in defence.
Still happeing. Can Blizzard do anything about this?