First, a cool visualization showing how much languages involve silent letters:
Meanwhile, scientists have shown that even when we are reading silently to ourselves, our brains are still hearing:
What’s particularly new about this study is that it not only shows that silent reading causes high-frequency electrical activity in auditory areas, but it shows that these areas as specific to voices speaking a language. This activity was only present when the person was paying attention to the task. The authors believe that these results back up the hypothesis that we all produce an “inner voice” when reading silently. And it is enhanced by attention, suggesting that it’s probably not an automatic process, but something that occurs when we attentively process what we are reading. And the next time you read silently, remember that it’s not quite to silent to your brain.