I was reading Augustine one day and was struck by a passage that referred a silent reading in a way that made it seem quite uncommon in those days. Here it is, referring to Ambrose of Milan: "When he was reading, his eyes ran over the page and his heart perceived the sense, but his voice and tongue were silent. He did not restrict access to anyone coming in, nor was it customary even for a visitor to be announced. Ve…
This seems greatly implausible. Consider, for example, the fact that the Roman walls were often covered in graffiti. The idea that a Roman would have to vocalize all of them to find one that seemed funny seems absurd. Further, there are examples in plays of a character reading a letter silently.
It does seem, though, that there have been times in specific cultures when reading prose or poetry aloud would have been considered the norm, and whether or not one could read silently, it wouldn't have been in anybody's habit to do so, because prose and poetry were "meant" to be read aloud. The notion, then, that someone could apparently "hear" all the musicality of the text while reading silently may indeed then have been cause for surprise.