I've made stage acting my trade, however I've had experience with phone recordings, independent cartoon narraration, and a wide array of character voices for a murder mystery comedy dinner theatre. I've sung as "Captain Courageous" in the spoof 20's musical "Dames at Sea" as well as done shows based on Monty Python's Flying Circus in which I presented myself as ALL of the characters.
I studied acting and voice work at Stephen F. Austin State University. I also attended a series of workshops based solely on tonal quality with a Mr. Johan Smith, an experienced actor from Kansas City. I actually taught my own series of seminars on dialect preperation while in college at the behest of the professors.
a small list of examples of character voices, dialects, impersonations...
Oxford English, Cockney, Irish, Scottish, Brooklyn, American East Coast, Southern "drawl", Jamaican, Australian, Indian, French, Marvin the Martian, Foghorn Leghorn, Jimmy Stuart early OR late years, most of the entire cast of Monty Python and all of their characters, the list is much more broad than this, however I can never remember all of them until I have occasion to use them.