Both my speaking voice and singing voice are pretty deep. I'm a baritone and I've been told many times from my acapellas that my voice is deep and a little raspy.
My voice is so deep that people can barely hear me.
And shouting is pointless for me since my voice
cuts out after anything higher than like 1 decibel.
I mean I can sing high notes, but I can't raise the
tone of my speaking voice. It just disappears.
THIS to be honest. But I can BELT out a song on some Whitney/Celine/Mariah decibels. My singing voice is powerful. But when it comes to speaking my voice is so deep it just fades away. And speaking louder takes extreme effort.
I do, kinda. It's so weird cuz I have been singing (AND EVEN TALKING) in my falsetto, according to my choir teacher
I watched videos on how to deepen it and it sounds pretty deep right now. I want it to stay this way, so sick of the high voice jokes.
Mine is weird because my voice and accent changes all the time. I can sing really REALLY high almost whistle register and quite deep not as deep as some.
It's usually not but sometimes I would just surprise people when a deep voice comes out when speaking
It just goes up and down, loud and soft 
And speaking louder takes extreme effort.