If you play a game on TV on Playstation 4, then it can suddenly happen that the sound is no longer transmitted. The result is that you no longer hear anything that can be fatal in some games.
But how can this problem be solved or avoided in advance? We would like to explain this in more detail here:
Before you start Playstation 4, you should first manually select the HDMI channel on your TV set to which the PS4 is connected.
Only when the TV is on the channel should the Playstation be switched on. We can't tell you what the technical background is, but the workaround described above almost always helps to solve the problem of suddenly dropping sound.