With so much focus in the publishing world on e-books, you might have missed the recent explosion in the popularity of audio books. They've become a billion-dollar industry with huge annual sales growth, in part because anyone with a smartphone can now also pocket an audio book. Alexandra Alter of the Wall Street Journal writes that the audio surge is changing the very way people read, "creating a new breed of literary omnivores who see narrated books and text as interchangeable."
These Narratextasaurs are certainly free to consume books however they please, and authors everywhere are no doubt thrilled with the rise of the species. But there's a real distinction between reading and listening that goes beyond any stuffy judgments made by book purists. Indeed, the evidence suggests that our mode of enjoying a book can alter the way we absorb its material. The very freedom granted by audio books—inviting the eyes to wander, and then the mind—may make them less intellectually interchangeable with printed ones than some readers would like.
Not long ago, a group of psychologists at the University of Waterloo in Ontario investigated the way our minds respond to various forms of reading material. They had 235 test participants engage with three excerpts of Bill Bryson's 2003 popular science book A Short History of Nearly Everything. The participants read one of the excerpts silently from a computer screen, read the second excerpt aloud off the screen, and listened to the third as the screen went blank.
During each of the three readings, the researchers tested for three cognitive impacts: mind-wandering, memory, and interest. Mind-wandering was measured with a prompt that appeared on the screen from time to time, asking participants whether or not they'd been paying attention. Memory was measured with a short true-or-false quiz after the excerpt. Interest was measured by participant rating.
Suffice it to say that listening and reading provided very different cognitive experiences. The minds of participants listening to the excerpt wandered significantly more than those reading it silently (which in turn wandered more than those reading aloud). The listening group also scored worse on the memory test than the reading groups did. And, oddly enough, listening even led to less interest in the passage compared to reading aloud (though not reading silently). The results were reported in the journal Frontiers in Psychology.
"It seems as though just listening is not as engaging as when people read, particularly out loud," Daniel Smilek, a co-author on the paper, tells Co.Design. "The way we're thinking about it is that the more your body's involved in the task, the less likely you are to be disengaged and mind-wander."
Smilek and collaborators draw a link between the amount of physical activity produced by a book and its grasp on a reader's mind. Reading aloud has both visual and vocal components, and reading silently at least requires the eye to keep pace with the page. Listening to a book, meanwhile, involves no real direct physical participation—making it easier for the mind or eyes to stray. (To that end, the research likely underestimates the mind-wandering effect of listening, since in real life there's much more to look at then just a blank screen.)
From a design standpoint, audio book producers could reduce mind-wandering by varying auditory stimuli. Different voices for each character or occasional fluctuations in volume, for instance, might nudge wandering minds back to the story. The concern with these external fixes, says Smilek, is that relying on them too much could weaken the internal focus we develop when reading off a page. "I worry that if you keep increasing the external support for attention we might actually atrophy the internal control for attention," he says.
Still, for many audio book devotees, the cognitive costs of retaining material or developing focus will be worth the convenience of incorporating books into other parts of their daily lives. The ability to listen and daydream and still complete a chore might be exactly the point. "I think people are just comfortable with that kind of tradeoff," Smilek says. Books are at their best when they take us somewhere, but taking them somewhere with us is a fine consolation.