I did this once a LONG time ago; I read huge swathes of The Bitter Road into the voice recorder I had at the time. It was... okay at the time. Of course, I didn't half know what I was doing with The Bitter Road anyway.
Well, here's version 7.5 of the Reveka/Romania/zmeu book, and I'm editing it per my editor's requests--AND right behind that, reading it all out loud for myself. At first, I paused the recording every time I hit something that needed to be fixed, and didn't let on what was fixed and what was old stuff. But now I'm in the recording swing of things, many chapters on, and I have started doing the whole process aloud. "Why did you use 'thing' twice in two sentences? Repetetive AND vague." And then I read the edited sentence, right after the bad first bit and the editing bit.
It's an excellent spur, too; if I don't feel the heart to go see what evisceration* awaits me in the next chunk of the line-editing, I just do a few chapters of what I've now termed "voice editing" and go on.
It helps with all the expected things--unclear antecedents and dropped words and editing artifacts--but where I am SURPRISED and DELIGHTED is how it helps with transitions. All kinds of transitions! Scene transitions. Emotional transitions. Logical transitions. To say that my characters occasionally make bizarre leaps of logic is to say that mosquitos like it hot and humid.
It is the single best thing I have done for this book, besides write the first draft.
* They are actually minor cuts and edits and comments. They are 95% of them good to extremely good to GREAT suggestions. The other 5%, I have no compunction ignoring. Yet, somehow, the sum total of all the cuts feel like major surgery. I wonder why this is.