Well living here in Kentucky and I've had a lot of people tell me I no accent at all I attest to the thick southern accents many here do have. I also found many in other southern states are heavy. The same with parts of Louisiana only not southern but creole accents. My wife picks up accents like a parrot, she hears it a couple of times and just falls into it.
two of my best friends live about 10 miles away from each other in Louisiana. one i can understand fully....the other, i have to tell him to slow down because i cant understand him if he talks to fast...lol
if the 2nd one has had a few to drink or starts talking about jambalaya...look out, i cant understand him..lol