So as I was playing last night i enter Bloodbourne cave and shortly save and quit do other things.
I come back to it and all sound but ambient music is gone.. Talk to my companion and no voice. No sounds when I use the pip-boy no sound when I fire my gun... Restarting the computer didn't help... nothing helped.

I got the same bug tonight as I entered the BOS bunker in hidden valley. No NPC voices, pip boy sounds, or vats noises. I could hear ambient sounds, guns, music and NPC voices outside of conversations. Doing a HARD reboot of my PC fixed the problem.