Navigating the world using echoes

Post date: 
Wednesday, 1 November 2017
Photo of a bat

“A real-life Batman” – that’s the proud tag Daniel Kish has earned through using the process known as echolocation to navigate his way around the world.

Daniel, a Californian who has been blind since birth, uses the reflected-sound waves technique employed by bats to live a dynamic life that includes hiking and mountain biking.
 
Daniel’s “human bat” technique involves using echoes from a series of repeated tongue clicks against the roof of his mouth, two or three times a second, to identify buildings, cars, trees, doorways and other potential hazards and build a mental picture of his surroundings.
 
“You send out a sound or a call and sound waves are physical waves – they bounce back from physical surfaces,” Daniel told the BBC. “If someone is clicking and they’re listening to surfaces around them they do get an instantaneous sense of the positioning of those surfaces.”
 
Using echolocation, Daniel can pick out a tall tree as opposed to a short one, or distinguish a metal fence from one made of wood. “Wood tends to reflect a warmer, duller sound than metal”, explains Daniel. 
 
Echolocation also allows Daniel to engage artistically with the world. “The sense of imagery is very rich for an experienced user,” he says. “One can get a sense of beauty or starkness or whatever from sound as well as echo. Even architecture has some distinction. One can click at a building, for example, and hear whether or not it is ornamented or featureless.”
 
Daniel, who has Masters degrees in psychology and special education, and is a certified orientation and mobility instructor, has set up a course, which he calls FlashSonar, to train people in his technique. It is run by World Access for the Blind, a not-for-profit organisation based in California, of which he is co-founder and president. Much of his work is focused on training children, including toddlers, to gain confidence and independence by using a long cane together with echolocation.
 

According to Emma Tracey, who writes for the BBC’s Ouch: Disability Talk, and has also been blind since birth, echolocation is a technique employed by all blind people as they go about their daily lives.

“You find yourself using your footsteps a bit loudly sometimes just to get your bearings,” Emma says. “Sometimes you click your fingers almost without thinking.”
 
Echolocation can be passive, in which naturally-occurring echoes are used, or active, which involves emitting a noise – either a click of the tongue or a tap of a cane – to produce echoes, which help to navigate the environment.
 
However, Emma explains that using sound to navigate has its limitations. “If it’s snowing it’s very difficult to get around,” she says.
 
Fiona Sandford, who runs the Glasgow-based blind support charity Visibility, invited Daniel over to train her outreach staff in FlashSonar. She likens the impact of his training to a piano student progressing from the ability to play a simple tune to performing a concerto. 
 
“Many people who are blind do use a form of echolocation,” Fiona told the BBC. “And what Daniel Kish does, he takes that ability and hones it.”
 
However, Fiona admits that the clicking noise is a barrier for some of her more self-conscious clients, especially the adults. “What we’ve found is the people that are most receptive to echolocation are young people,” she says.
 
Daniel agrees that relatively few blind people use active echolocation to the extent that he and a few others advocate. “In many instances it’s discouraged,” he says. “I personally have worked with students who’ve come from schools for the blind, for whom clicking was actively discouraged. I believe it’s discouraged because it’s seen as a ‘blindism’ – if you’re clicking then you’re drawing undue or negative attention to yourself.”
 
Credit: The information for this article was sourced from the BBC News website – you can find the original articles under "Further information" below.
 

Further information

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