This isn't limited to actors, by the way. You could be a Fellini-esque director. Or be a John Toll-like DP. Or a Charlie Kaufman-type writer. The thing about your voice is that a) you can't fabricate it and b) you only discover it after years of doing whatever it is you do. Once you find it (or it finds you), you can try to ignore it like Ben Affleck, work to counter it like Nicolas Cage, or embrace it like Jack Nicholson.
I vote for embracing it because if it's true to you, you're not going to fool anybody by denying it.
What's funny about types is that they don't necessarily spell success for the prototype. (That's where that word comes from, by the way. I just figured that out.)
I once directed a regional phone commercial that had a one-line role for a mailman. One actor who came in was amazing. He took that one line and gave it back to me dozens of different ways. He added not just an accent, but could dial in the amount of accent. He was an utter pleasure to work with and I knew immediately that he was far greater than the role.
I didn't recognize him, but it was Richard Sanders, who played Les Nessman on WKRP.
The other example is comes from a documentary I saw about Charlie Chaplin. Apparently, at the height of his popularity, Mr. Chaplain found himself inspired to enter a Charlie Chaplain Look-Alike contest. He didn't even make the finals.