A new study has looked into the strange phenomenon of human echolocation, where people are able to “see” their surroundings by clicking their mouths.
This ability shot to the fore in 2006, when a then 14-year-old child called Ben Underwood appeared on TV claiming the ability. Known as Sonar Boy, he said he could use clicks to navigate, despite being blind. “I’m not blind, I just can’t see,” he reportedly said.
Others like Daniel Kish, who calls himself the real-life Batman (although perhaps Daredevil would be more appropriate) also use echolocation to better navigate the world. In the short video below, Kish shows off his talent, even riding a bike while clicking to avoid hitting cars.
Now this new study, published in PLOS Computational Biology, has attempted to work out the acoustic mechanisms behind human echolocation. They recorded and analyzed several thousand clicks, from three blind adults trained in echolocation, to work out how the sound waves moved in an acoustically controlled room.
The adults were put in an empty room, and asked to click as they usually word. The researchers found that the clicks had a distinct beam pattern, much more focused than human speech. Each click also lasted just 3 milliseconds, quicker than reported by previous studies, and had frequencies of between 2 and 10 kilohertz.
"One way to think about the beam pattern of mouth clicks is to consider it analogous to the way the light distributes from a flashlight," Lore Thaler, lead author of the study from Durhman University in the UK, told ScienceAlert. "The beam pattern of the click in this way is the 'shape of the acoustic flashlight' that echolocators use."
There are still some unanswered questions, though. They’re not quite sure yet how the noises can reveal physical features of an object. They now want to use a mathematical model to recreate the clicks made during human echolocation, which will let them create a large number of clicks that make studying the phenomenon easier.
"The results allow us to create virtual human echolocators," Thaler said in a statement. "This allows us to embark on an exciting new journey in human echolocation research."
