I've been asked this question a lot and I hate it. I’ll describe why in a bit, but for now I’ll just change it to “does your mind do more or less the same thing when you listening to an audio book and when you read print?”[Read the rest for some examples of types of reading which an audiobook might result in better or worse comprehension than reading hard copy.]
The short answer is “mostly.”
An influential model of reading is the simple view (Gough & Tumner, 1986), which claims that two fundamental processes contribute to reading: decoding and language processing. “Decoding” obviously refers to figuring out words from print. “Language processing” refers to the same mental processes you use for oral language. Reading, as an evolutionary late-comer, must piggy-back on mental processes that already existed, and spoken communication does much of the lending.
So according to the simple model, listening to an audio book is exactly like reading print, except that the latter requires decoding and the former doesn’t.
Is the simple view right?
Some predictions you’d derive from the simple view are supported. For example, You’d expect that a lot of the difference in reading proficiency in the early grades would be due to differences in decoding. In later grades, most children are pretty fluent decoders so differences in decoding would be more due to processes that support comprehension. That prediction seems to be true (e.g., Tilstra et al, 2009).
Especially relevant to the question of audiobooks, you’d also predict that for typical adults (who decode fluently) listening comprehension and reading comprehension would be mostly the same thing. And experiments show very high correlations of scores on listening and reading comprehension tests in adults (Bell & Perfetti, 1994; Gernsbacher, Varner, & Faust, 1990).
This is a topic I think about slightly guiltily at times because it's got to the point where the majority of the books I read each year are on audiobook. I still very much enjoy getting the chance to sit down with a physical book and read. One of the things I enjoyed very much about our vacation last week was that I was finally able to read two books that had been sitting on my "to read" pile for months if not years. But for various reasons, I have very little time to sit down with a book at this time in my life. What little time I do have is snatched from potential sleep time. Yet somehow, while sitting up till one or two in the morning writing and getting 5-6 hours of sleep a night worked for me while actively composing on the novel, if I try to sit up and read until a similar time I find my vision blurring and I eventually have to give up and go to bed. Typing kept me awake in a way that reading does not, even if I very much want to stay up late reading.
The way that I try to make up for this is with audiobooks. On the average day I spend an hour in the car driving to and from work. That now becomes potential reading time. So does time spent mowing the lawn and sometimes doing dishes or other housework.
In some ways the experience of listening to books differs from reading in print -- not necessarily better or worse, just different. Particularly good readers become imprinted on a book's voice. Even if I read in print, I hear any Patrick O'Brian novel in Patrick Tull's voice, and Dance to the Music of Time now will always flow for me in the cadence of Simon Vance's tones. Because I'm reading while doing activities, particular memories of books become tied to particular places or activities: Mowing a difficult spot under the playscape is closely connected with a letter that Churchill's wife wrote to him about how he should improve the way he dealt with subordinates, putting up storm windows in the guest room is forever connected with a passage in War & Peace in which Nickolai rescues a Polish girl and her father. It's not just that these passages of the books now remind me of these activities, but that returning to a place or activity will suddenly bring up a snatch of prose that I heard in connection with it.
Yet there is a guilty, cultural feeling that this isn't "real" reading. Perhaps this ties back to the way that we learn how to read. In my family, there was a strong tradition of reading aloud. Some favorite books (such as The Hobbit and Watership Down) I heard read aloud by my father before I read them myself. Yet even so, I went to school, filled out my BookIt forms to get pizzas at Pizza Hut, and got stars next to my name for the books I read myself. Being read to by a parent didn't count.
This is doubtless for the reason that Willingham gives in his post: children in the early grades are still learning to decode text and mentally turn that into comprehensible words. However, most people have this pretty well nailed by fifth grade or so. When I listen to a book instead of reading a printed copy, it's not because I find reading printed words difficult and listening is some sort of easy way out. "Cheating" is an idea that suggests I am somehow getting a benefit that I don't deserve. But is the audio-reader really getting an undeserved benefit by listening rather than reading pages? Is he somehow failing to put in the "work" of reading?
Not really, but it's still hard to shake that grade-school feeling that you're getting away with something. So while this formulation of decoding versus comprehension will even more than before give me a rational assurance that I am "really reading" a book that I listen to, I doubt I'll be able to completely shake the feeling that I am "cheating" somehow.