That's what St. Augustine would have done...
"…Christianity also seems to have been the catalyst for a new kind of reading, closer to thought itself. Reading in the ancient world had always been a kind of performance, in which the characters written on the page were converted into a stream of spoken language, available to be understood by the reader himself, but of course also for any others present, in the living room or in the classroom, wherever the reading was taking place. Silent reading does not seem to have been considered, despite the inconvenience that must have been encountered when more than one person in a room wished to read different books at the same time.
The first reference in the western tradition to silent reading was Augustine’s almost incredulous report in his Confessions, of how he first witnessed it being practiced by Bishop Ambrose of Milan, when he knew him in the 380s. He described it as a sort of book communion: “But when he read, his eyes were led over the pages and his heart sought out the understanding, while his voice and his tongue were quiet.” Augustine, a highly vocal man, whose career was one of open discussion and oratory, and who indeed wrote his many books by dictating out loud to a secretary, could only conjecture that Ambrose might have been doing it to save his voice or perhaps to save potential listeners from perplexity in case they might have overheard him reading something that was just too difficult for them. But in this Ambrose, and not Augustine, was the man of the future." (p. 121-2)
(text from Ad Infinitum - see below)