Hi, sorry for the late reply!

The in-game settings don't offer much in the way of configuration other than the volume on the PS4 version. I have my PS4 set to output in Linear PCM which is the highest quality option it supports, I've also tried the other options and it didn't make a difference.

My Set up is both of the following:

PS4 -> Optical output -> DAC -> Amp -> Headphones

and also my standard TV speakers, the problem is heard easily on both of these set-ups.

Here is a video of the issue:

https://www.youtube.com/watch?v=h_rcJBHIRKE

If you listen to the singing you can tell it is very compressed compared to how it sounds in this version:

https://youtu.be/tBucPlhhXd8?t=3m5s

Thanks again for your help!