I have updated Realistic Darkness for B19.
It is a XML mod and the original is already B19 compatible. But if you use the B18 version then you won't have any ambient sounds because the file names have changed. I updated the file names to B19.
Original Mod: https://steamcommunity.com/sharedfiles/filedetails/?id=740930354
B19 Update: https://github.com/devent/Realistic_Darkness