How a writer finds their voice

Russell T. Davies, producer & writer of the utterly wonderful Doctor Who revamp, has a new book called A Writer's Tale, excerpts of which are appearing in the London Times. There's a lot of good stuff in here for anyone who makes a career out of self-expression--"A hundred versions of me, and every single one sounds like a fool" echoes my own inner voice after I give a talk, no matter how successful--but the following rumination on the writer's voice is particularly noteworthy:

You ask how a writer finds their voice. Now, that's a question!... Gaining a voice, whatever that is, comes with experience and practice - and the writing, again, is indivisible from the person. Your voice tends to be something that other people talk about, about you. It's not something that you think about much yourself, and certainly not whilst writing. I never - never - sit here thinking, what's my voice? You might as well ponder, who am I? It is, in fact, exactly the same thing. You can wonder your whole life and you'll never get an answer to that.