Yeah it's a bug, have it hapenning constantly on my PS4. Have already posted about it prior to the recent patch. Hoping they'll address it for the next patch as I'd had to stop playing it, doesn't feel the same without sound.
I'd like to affirm this, sound effects and music sometimes just cut out still with this latest patch. The starter cave in Heiberhiem(?) seems to have this happen the worst, it'll happen within minutes of loading a game.
