Dan Drezner takes an online quiz and finds he has a “midland” accent. His evaluation says:
“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.
The number of people who sincerely believe they do not have an accent is quite astonishing. Maybe quizzes like this are partly to blame.