"Shitty First Drafts"

Lamott isn't literally referring to "voices" that float around in her head. She is referring to her conscience and how it interferes with her writing. I don't personally hear voices when I write, but I do subconsciously proof read my work as I go. In my opinion, writing is a process. Depending on the author it could be a long process, as with Lamott, or a short one. It usually takes me a number of hours and about two drafts to have a complete product. I agree with Lamott, whole heartedly. The greatest writer has some sort of process and ususally it starts with a "shitty first draft."