I’ve just found a fascinating article by Lisa Theriot on accents, that also pokes a little fun at “the curse of Dick Van Dyke” if you’ll recall his performance in the film “Mary Poppins”.
While you’re at it, there’s a very good book by Robert Blumenfeld called, Accents: A Manual for Actors.
Plus it comes with a very handy CD. The man has an amazing command of just about every accent on earth, including regional dialects. Very helpful for creating characters in audio book , character, and other voice acting work.
I just copied the image- The “look inside” doesn’t work if you click the image.
But if you’re so inclined click a peek, do it here: Look Inside