Well, Theresa, I think I "hear" that passage in a growly voice, not my own. But I listen to audiobooks all the time, and all the "voices" in an audiobook are performed by one reader, and he/she often changes tone or accent to fit the narrator, without of course changing his/her own voice. The male reader, for example, raises his voice a bit to signify that he's "being" a woman character, but otherwise I think tries to replicate more closely the other markers of this character-- the accent and the diction and attitude and mood. The best readers are really artists at this.
Anyway, I think since I've started listening to audiobooks, my "inner voice" is a lot more varied.
Remind me that I should address the audiobook and how experiencing that reader changes the experience of the book, etc.