Tiny as they are, bats have the ability to "see" in the dark by using a special skill called echolocation (回声定位法). They make noises and wait for sound waves, or an echo, to bounce back off objects. They can tell the distance of various objects by how quickly the sound waves bounce back off them. If no sound bounces back, they can then fly forward.
This special ability has been copied in the human world for a long time, such as in submarines and planes. But apart from helping vehicles "see" where they are, what if blind people could use echolocation for themselves? American Daniel Kish, who is blind, is known as "Batman". This isn't because he walks around in a cape (披风) and a mask, but because he has a bat-like ability to locate where he is through sharp clicks he makes by moving his tongue against the roof of his mouth. Kish is so skilled at echolocating that he can ride a bike and hike on his own.
Recently, a research carried out at the University of Durham in England shed some light on the power of human echolocation. Kish, as well as other volunteers, worked with a group of scientists who studied the way blind people listen to the echoes that they produce from clicks. The team found that people were capable of hearing even very faint echoes, ones far fainter than had been previously thought.
Lore Thaler, lead scientist of the group, said, "We found that in some conditions, they were really faint-about 95 percent softer than the actual clicks, but the echolocators were still able to sense this."
Andrew Kolarik, another expert in echolocation, told BBC News that echolocation "can be very useful at providing information at face or chest height" and could help people "avoid objects like low hanging branches that might not get detected by the cane or a guide dog".
According to BBC News, echolocation is a skill blind people can acquire and develop, just like learning a language. As Kolarik said, "Teaching echolocation skills could provide blind people with the means of exploring new places."