I did not think they are loud compare to Great horn or Barn Owl.
Tame, yes. I had a family that visited my back yard on a daily base. I would have one of parent perch on my hand. they had three little ones that would circle me and catch June bugs. They would at times perch on my feet. I miss them 
I've never heard a barn owl other than from recordings. I've heard all sorts of great-horned, barred, screech and saw-whets. I actually used to lead groups at night to go out and call/locate/listen to them.
They have a range of sounds. Some carry better than others, and sometimes they call with more volume. Sometimes they can barely be heard even when you're right next to them. Sometimes they can be heard clearly from a distance.
My all-time favorites are the barred owls, especially when a pair gets going and they answer each other back and forth!