Saturday September 23, 2017

Watch this blind man 'see' the world with sound

Born blind, Brian Borowski uses sound to "see" 1:00

Listen 16:20

A rare skill

Most blind people manage with guide dogs and canes, but a few have developed what seems to be a kind of superpower: they can echolocate. Like bats or dolphins, these people have learned to generate sound, and listen to reflections and echoes of these sounds to orient themselves and locate objects in their environment.

Brian Borowski, a computer programmer in London, Ont., was born blind. As a child, he learned that short, sharp clicks of his tongue against the roof of his mouth could be used as a sonar source. Indoors, he listens for how these clicks bounce off walls, windows and doors to navigate around buildings, and he can locate objects as small as 10 or 20 centimetres. Outdoors, he echolocates buildings, fences, trees, lamp posts and cars, and navigates what he calls his three-dimensional world of sound.

Understanding human echolocation

Dr. Lore Thaler has been studying human echolocation for more than a decade.  In fact, some of her early work in the field was at Western University in Ontario — and Brian Borowski was a volunteer.

During her career, she's studied how blind echolocators recruit parts of the otherwise unused visual cortex when using their sonar, and investigated how echolocation adds to the toolkit of skills blind people use to navigate the world.

She's also investigated whether sighted people can learn to echolocate — and worked on the skill herself.  

echolocation

An echolocater's 'beam' of sound concentrates reflections in front of them. (Thaler et al.)

In her most recent work, she's been focusing on the very characteristic sonar "clicks" that, entirely independently, many echolocaters have learned to generate.

These clicks are very brief — only three milliseconds — and have very precise frequencies.

This, she thinks, means that blind echolocators have independently discovered the best sound that can be produced for echolocation.

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