David Cowan is the ASL interpreter for the state of Georgia, and he's attracted a legion of fans from around the world. His full, white beard reminds some people of Santa Claus. And his stylish, dark clothes stand out. According to Cowan, it’s easier to see his interpreting against a dark background. Fame aside, there are thousands of people who rely on him for critical information. According to the World Health Organization, nearly half a billion people worldwide have disabling hearing loss.