The voice inside my head sounds exactly like I'd like it to. It usually has something to do with whatever I have just heard. If I have just heard a different accent than my own, that's what the voice in my head sounds like. I then proceed to talk in whatever accent I have just heard, until I am either satisfied with it, or I hear a more intriguing accent. If I haven't heard anything, it is just like my real voice, or at least the way I think it sounds when I talk. When I hear a recording of myself though, the recording is much deeper than what I perceive my voice to be.