Here, I am reminded not of the recent past but of a huge change that occurred in the middle-ages when humans transformed their cognitive lives by learning to read silently. Originally, people could only read books by reading each page out loud. Monks would whisper, of course, but the dedicated reading by so many in an enclosed space must have been an highly distracting affair. It was St Aquinas who amazed his fellow believers by demonstrating that without pronouncing words he could retain the information he found on the page. At the time, his skill was seen as a miracle, but gradually human readers learned to read by keeping things inside and not saying the words they were reading out loud. From this simple adjustment, seemingly miraculous at the time, a great transformation of the human mind took place, and so began the age of intense private study so familiar to us now; whose universities where ideas could turn silently in large minds.Dr. Barry Smith, University of London, while discussing Edge Magazine's 2009 question, What will change everything?
Edit: a commenter has suggested it was actually St. Ambrose, not St. Aquinas, who first broke this ground.