If you've listened to an unabridged audio book, does it feel the same to you as having read the book? Would you think of it the same of it as if you'd consumed it with the eyes after having consumed it via your ears instead? I'm not quite sure. I can't clearly point out any disadvantages hearing the unabridged book over having read it - except I was raised to value reading so much that I wouldn't say of myself I know a book, I'd just say I listened to the audio version, as if it was somehow inferior. Old fashioned thinking?