I just stumbled upon an interesting site. If you are of a particular bent, this is the sort of place where you might lose many valuable work hours. It is the International Dialects of English Archive. It might be helpful to listen to this when trying to get a handle a new character! Also, nerds just like absorbing catalogs of stuff.
By the way…I make no claim that this is the best or a unique resource, so share if you’ve got something cooler!