BBC News
18th March 2019
The power of our hidden senses
I am sitting at my desk with my eyes closed, moving a dinner plate back and forth in front of my face while repeating “Test! Test! Test!”. It may look eccentric, but I am trying to teach myself the fascinating skill of echolocation: navigating the world by echo, just like a bat, or a dolphin.
Echolocation has gained prominence in recent years as a skill that some blind people use to map their surroundings with astonishing precision. They can detect trees, buildings or doorways by making a clicking sound with their mouth and listening for the echo.
But research has shown that the basics of orienting yourself this way can be learned by anyone, blind or sighted. A growing body of research encourages us to expand our sensory potential – awakening senses that have been neglected, suppressed, or even considered outside the human realm.
Human echolocation has been known as a concept since the 1940s. But it has only been studied systematically in the last decade, both as a potentially life-changing skill for blind people and as a way of examining how our brain deals with sensory information.
Some people are experts at navigating the world by echo, like a dolphin
“We measure the best possible human echolocators, what we refer to as ‘echo experts’,” says Lore Thaler, a psychology professor at Durham University and one of the world’s leading experts on human echolocation. “These are typically people who’ve used it for a long time and show just really good acuity. They can do things which, if you’re new to this, you just cannot do.”
Audio-visual
Just by using mouth clicks, echo experts can detect whether a disc one metre away from them has been shifted by about the width of a finger. They can tell whether an object 2m (6ft 6in) away is a lamppost, car or tree. Even those quite new to the skill can detect a wall more than 30m (98ft) away.
This does not mean echolocation provides people the same accuracy as vision. Some bat species can use ultrasound to hunt moths, but human echolocators struggle to track such tiny targets. And since echolocation only works for three-dimensional objects, it cannot be used to read printed texts, for example.
Used alongside traditional aids, echolocation can be transformative for blind people
However, Thaler says it is still a very powerful technique. Used alongside traditional aids such as a cane or a guide dog, it can be transformative for blind people, her research has shown. It can help them travel more safely, avoid obstacles at head level, even recognise their own porch. “It’s these little things that can make a difference to how confident someone is, and if they are happy to go out,” she says.
http://www.bbc.com/future/story/20190314-the-power-of-hidden-senses-like-echolocation