New York Times article from 2005 sums up a lot of my thought process.
If you've read my book reviews, you know that's changed. I gradually came to realize that I was still taking in just as much of the story, whether I read the words with my eyes or absorbed them through my ears. After all, I still remembered the story of The Hobbit quite well when I got around to reading it, and I'd originally encountered it as a bedtime story, read over the course of some weeks by my father. (My dad also has a voice trained for radio, so his bedtime stories are a real treat.)
What changed my mind, mostly, was my job. As part of my work duties, I drive all over Troy, Albany, East Greenbush, and everywhere in between. Some days I'm only in the car for 30 minutes to an hour, but my average day has me spending nearly a third of my clocked time behind the wheel. I don't like the radio, because I hate hearing the same song more than once or twice a day, even if I like it. My own music gets boring after too many repetitions.
As soon as I realized how many hours I'd wasted on listening to the same music again and again when I could've been taking in a new book, I kicked myself. Listening to an audio book and paying attention to the road take up entirely different parts of my brain. If anything, audio books occupy the part of me that gets distracted. I find my attention sharpened, my alertness heightened. That isn't the case for everyone, and some people need to get used to taking in stories aurally before it's safe to listen and drive, so be aware you may need an adjustment period.
I tend to read most of my YA in audio form, because shorter books are easier to take in, and they tend to hire the more dynamic narrators. On the other end of the spectrum, I also prefer longer classics in audio, because I can take the time to appreciate the richness of the language when I don't have to worry about straining my eyes.
Because I get most of my audio books from the library, I'm apt to pick up things I wouldn't normally touch. I would've given up on the Stephanie Plum and Harry Dresden books much sooner. Whether that's a point in their favor or not, I can't say. I also wouldn't have read Kristin Hannah's, Jeff Lindsay's, or Alan Bradley's books, and that would have been a loss.
Some books have been enhanced by the audio experience (Margaret Atwood's The Year of the Flood, Jay Asher's Thirteen Reasons Why, and The Guernsey Literary and Potato Peel Pie Society by Mary Ann Shaffer and Annie Barrows come to mind). Others may have been spoiled by a clipped or lazy reader, though it's hard to say for certain whether it was the book or the narrator that was lacking.
About half of the books I read every year, I take in on audio. I have a queue of books to request from the library for future listening, and a short backlog of books I'm going to listen to next. My husband got me an iPod for Christmas a couple of years ago, and it's quite useful for importing a book, then plugging into my car.
There are some drawbacks to listening to books on audio. I don't know how things are spelled, so I always have to look up character listings and place names before I type up book reviews. I can't quote from the books I read on audio, because my memory isn't that good. And it's really hard to reference an earlier section of an audio book, especially when I'm driving. I can go back to an earlier track if I wasn't paying attention or if a loud noise drowned out the book, but I can't flip back to a certain passage or look something up. Not easily.
Since my commitment to audio books, I've had a number of long car trips made more sane by listening to books, and I've discovered a lot of authors I'd been neglecting. Overall, I'm glad I opened my mind to listening to audio books, and realizing they counted just as much as making my eyes do all the work.