Yes, I've seen and experienced that same thing myself in my current game. Though I didn't start a new game with the last opt-in update so I don't know if that had anything to do with it.

I was actually shocked the other night as the sound finally came back in the battle viewer after being absent for a long time. Of course it's gone again now. Still loving the game and playing the heck out of it though!

Interesting; I nearly always play video games with the sound, especially music, disabled.    Maybe it's an age thing, but if I listen to music for even a short time it may stick in my head for a week and drive me even crazier than I already am.   Sigh, I am missing out on some good stuff, but then, I don't have to get it working either.

I think I can pin down exactly when it started; the stunning and surprising scene in Dragon Age when Leiliana sings her song.  And when It was still in my head many days later I realized I had to let music go in a sense.   Now if somebody just mentions the title of some old favorite it may start up and keep going around the clock. 

I hope you guys get it sorted, sound can be a real sticky issue for those who are allowed to listen.