I've noticed what seems to be an issue with the voice audio when running the game with Portuguese audio selected. The volume for the voices is far too low compared to when running it with English audio (about 30-40% of the volume). In some scenes, you can be right up to another character's model and still be barely able to hear them.
I have a 5.1 system connected over an optical cable, and I'm fairly certain it's set up properly. The audio settings both on the PS4 system menu and the game's audio menu are set to 5.1, and I've tested both the Dolby Digital and DTS outputs to my receiver (it is compatible with both). Again, the voice volume and positioning when playing with English audio is perfect, everything comes off the proper speaker and with proper volume -- therefore I think this has very little to do with my setup. When you switch it over to Portuguese audio, the sound effects keep their volume, but dialog volume seems to be turned down (though properly positioned).
All volumes in the audio menu are set to their default (100%) and I do not change any settings on my equipment between language switches. Other games and blu-ray discs have their audio working properly on the same system with the same settings.
The issue carries over even when you force the game down to 2.0 audio or hook it up to the TV directly over HDMI only (audio also going through HDMI to the TV). Only the Portuguese audio voices seem to be at a low volume.
Is this a known issue? If it is, it sounds (from my layman point of view) as if it's something easily patchable with an overall volume boost to these particular voices. They are low across the entire game. The voice acting and quality is actually pretty good, it seems like a waste to have the volumes messed up. I've seen other players reporting this both on their PS3 and PS4 versions of TLOU on some Brazilian forums, but nobody seemed to think to post it here on the PS forums... I did search ;P
If anything, could anyone bored enough try this out on their game and see if the voices also behave like this when they switch to Portuguese?