Hello,
I have been playing this game for about 2 weeks and haven't encountered a single problem until today.
I was playing for a while, then quit the game for a 2 hour break and then launched it again to continue playing, only to discover that the dialog sound was gone. I could still hear footsteps, fire, background music etc. but not people speaking.
After loading a different saved game and reloading the original saved game again, it worked fine for a little while, and then the sound problems began to appear randomly.
Sometimes dialog goes away, sometimes the background music goes away but dialog sound is heard, that satisfying sound when you complete a quest is not heard, etc.

I have tried restarting the game and my PC but nothing seems to help.

Any suggestions?