It seems that it was possible before using a WMP Enhancement, but the [manual][1] I found seems to be for an older version, since I can't find this option in WMP 12.
[![Screenshot][2]][2]
Is it still possible to play different audio files with different volume levels automatically normalized?
[1]: http://On%20https://www.windows-media-player.com/set-up-the-same-volume-level/#:~:text=1)%20In%20Windows%20Media%20Player,in%20the%20following%20screen%20shot. [2]: https://i.stack.imgur.com/urKM6.png