Midland
"You have a Midland accent" is just another way of saying "you don't have an accent." You probably are from the Midland (Pennsylvania, southern Ohio, southern Indiana, southern Illinois, and Missouri) but then for all we know you could be from Florida or Charleston or one of those big southern cities like Atlanta or Dallas. You have a good voice for TV and radio.
I majored in Radio and TV production in college. I spent 4 years getting rid of my Louisville twang and I was a traffic reporter and did some voiceover work in my former life.
PS: I was born and reared in Southern Indiana, too.
:-)
