I can reproduce this bug easily. Just start the game (tutorial) and speak to a NPC (with, maybe, voiceover) and my sound gets killed. Entirely. Meaning that i cant hear TS3 or any music that was runing in the background.
Runing only STO gives the same problem. I did not have that big problems in the OB. Sometimes the sound crashed (which i could not reproduce) but after a while it was stable.
I am runing an Audigy2 (with latest drivers).
After the sound gets killed i need to restart every application i was runing to have their sound work again.
I don't think the problem is on my end. I hope Cryptic will find a patch for this.
Without sound STO isn't fun at all, so i'll take a break until this issue is solved.