As any Daredevil fan can tell you, humans with impaired vision can learn the incredible ability to “see” the world around them through echolocation. Using a series of clicking noises to bounce sound waves off nearby objects, they are able to build a "mental image" of their surroundings by listening to the subtle sound of their click's echo, much like a bat or a whale.
A team led by scientists at the University of Durham in the UK have recently been studying this “superhuman” ability and discovered that humans are actually surprisingly good at it, with an ability to subconsciously adjust their clicks to suit different environments.
Their findings were recently published in The Proceedings of the Royal Society B. One of the authors of the study is Daniel Kish – aka “the remarkable batman” – who was born blind but has since managed to master the art of echolocation. He has also established the nonprofit World Access For The Blind.
"[Clicks] are flashes of sound that go out and reflect from surfaces all around me, just like a bat's sonar, and return to me with patterns, with pieces of information, much as light does for you,” Kish explained in his 2015 TED talk (video below).
“My brain... has been activated to form images in my visual cortex, which we call the imaging system, from those patterns of information. I call this process flash sonar.”
For this new research, the team gathered eight blind participants who use echolocation in their everyday life. In a small, sound-deadening foam room, they were put to the test to see how accurately they could identify the direction of a disc that was 100 centimeters (3.3 feet) away.
When the disc was straight in front of them at mouth level, they could detect it with 100 percent accuracy. The main takeaway from this study was that people’s clicks intensified and became more rapid if the object was at an angle to them. Their success rate decreased to an average accuracy of 80 percent with angles of 135 degrees. This decreased further to 50 percent when the disk was directly behind them.
"Our results clearly demonstrate that people, just like bats, adjust their emissions to situational demands," the study authors note.
"Our results are, to our knowledge, the first to demonstrate that human echolocators adjust their sound emission strategies to improve sensory sampling, highlighting the dynamic nature of the echolocation process in humans.
As previous studies and anecdotal evidence have shown, the echolocation skills of some blind people are so finely tuned that they can identify an object’s shape, size, distance, and material just by making a few clicks. It's an undeniable skill, one that's a testament to the incredible flexibility of the human brain.