Everyone faces difficulties in their life. Daniel Kish was born with a special eye illness and lost his eyesight before he was only 14 months old.
Soon after, however, he started to do an amazing thing. He learned to make clicks (咔哒声) with his tongue to help him move around. Kish now moves about using sonar (声呐). He is so good at it that he can ride a bicycle by himself on public roads. And he started the organization World Access for the Blind (WAFTB) in 2000, teaching others how to use sonar. In the interview with National Geographic, he explains how the sonar works.
"When I make a click sound, it produces sound waves. These waves reflect (反射) off surfaces all around and return to my ears. My brain then deals with the sound and turns it into pictures in my mind. Each click is like a camera flash, which helps me make a 3-D picture of my surroundings for hundreds of feet. It's like having a conversation with the environment."
Kish feels it is exciting to ride a bike using sonar, although he needs to click twice a second, much more than he usually does. "It may sound a bit dangerous to move around the world in this way," he says. "But most people in the world live in fear of things that they imagine. I love hiking and mountain-biking. I go almost everywhere. And I've never had an accident and hurt myself."
He is happy to be able to help more blind children to improve their life. "We've served over 10, 000 students in nearly 40 countries," he tells the reporter. "Many students are surprised how quickly results come. Seeing isn't in the eyes. It's in the mind."
①The sound waves reflect off surfaces.
②The person makes a clicking sound.
③The brain turns the sound into pictures.
④The sound waves reach the person's ears.
