Just wanted to add, becuase this just happened to me, and i tried everything and nothing worked. So then I tried to do my own troubleshooting and I went through ps4 settings and went to sound and screen, then video output settings and for deep color output, I had set mine to automatic so I switched it to off and now I have audio again! So to experiment I turned it back to automatic and I still had audio, so tbh idk if i got lucky, but more then likely when I switched that setting it forced the ps4 to respring or reboot and audio came back. Id figure I should make a profile for here just to add another possible solution. Good luck everyone.