Daniel Kish is a remarkable man. Having lost both eyes to retinal cancer when he was 13 months old, he is insatiably curious and has taught himself to navigate by clicking his tongue and listening for echoes. Scientists call this method echolocation but Daniel calls it FlashSonar.
Today Daniel is a perceptual navigation specialist who is making an enormous difference to many people's lives. Both blind and sighted people can benefit from echolocation. It expands their perceptual toolbox by enabling them to observe their surroundings by means of sound rather than sight.
If you'd like to see Daniel in action, watch his TED talk: "How I Use Sonar to Navigate the World". Here's the link: How I Use Sonar to Navigate the World