Wrote James Fenton in The Guardian, back in 2006. (I'm reading it today, because Arts & Letters Daily linked to "Literature Shrugged/Worse than hatred of literature is indifference," which linked to it.)

Many people are affected by a passage in St. Augustine's "Confessions," describing Ambrose reading silently: "His eyes traveled across the pages and his heart searched out the meaning, but his voice and tongue stayed still."

Scholars have sparred for decades over whether Augustine's offhand observation reveals something momentous: namely, that silent reading--that seemingly mundane act you're engaged in right now--was, in the Dark Ages, a genuine novelty. Evidence abounds that ancient and medieval readers relished giving voice to their favorite texts in order to appreciate more fully the cadences of Homer and Lucian. Of course, we equally enjoy reading poetry aloud. The question is: Could the earliest readers literally not shut up?

What shocked Augustine was that Ambrose read silently in front of visitors and refused to share his reading matter, and his thoughts, with them. But Augustine was perfectly capable of silent reading, and describes a key moment in his conversion as a moment of silent reading with a friend. As Gavrilov concludes: "... the phenomenon of reading itself is fundamentally the same in modern as in ancient culture. Cultural diversity does not exclude an underlying unity."