How blind people map their surroundings using sound

Some blind people use returning echoes from their own mouth clicks to perceive external surroundings, or echolocation. New ...
The Times of Northwest Indiana

Computer opens new world for blind

VALPARAISO -- Blind since 1989 due to a bout with glaucoma, Thomas P. McCormick, 77, is finding ways to "see" by using the latest in computer technology. He has a computer at home, but had not been ...