Scientists at Oxford say they've invented an artificial intelligence system that can lip-read better than humans. The system, which has been trained on thousands of hours of BBC News programmes, has been developed in collaboration with Google's DeepMind AI division. "Watch, Attend and Spell", as the system has been called, can now watch silent speech and get about 50% of the words correct. That may not sound too impressive - but when the researchers supplied the same clips to professional lip-readers, they got only 12% of words right. Joon Son Chung, a doctoral student at Oxford University's Department of Engineering, explained to me just how challenging a task this is.