[Nfbf-l] How scientists are helping blind people see with their ears.

[Alan Dicey]

How scientists are helping blind people see with their ears.
Updated by Susannah Locke on November 7, 2014,
@susannahlocke susannah at vox.com

Bats, dolphins, and even some whales all use sonar to determine the location 
of objects around them - by sending out sound waves and listening to how 
they bounce back. This allows these animals to do all sorts of amazing 
things, like hunt in total darkness.

And it turns out that humans can use sonar, too (and not just in 
submarines).
Some blind people are capable of using tongue clicks to "see" their 
surroundings. They make a sharp sound with their tongue and listen carefully 
to how the sound reflects off the objects around them.

So, more recently, researchers have been trying to push this capability 
much, much further.
New technologies - lasers, cameras, and earphones - can give people even 
greater sonar capacity. More radically still, some researchers have now 
developed software that essentially translates the world into music, which 
can help blind people avoid obstacles, recognize facial expressions, and 
even read letters.

How sonar works - and how humans can use it.

The basic idea of sonar is to send out a sound and then time how long it 
takes for the sound to bounce back. That can give a sense of how far away 
various objects are. Submarines do this, as do animals (it's often referred 
to here as "echolocation").

And a few humans have mastered the trick. Take Daniel Kish, who has been 
blind since childhood and can echolocate by clicking his tongue. Using this 
technique, he says that he can see objects fairly far away, as long as 
they're at least the size of a softball. (Kish is president of the 
non-profit World Access for the Blind foundation, which among other things 
promotes the teaching of echolocation.)

And human echolocation has also attracted the attention of academic 
researchers.
One group in Spain determined in 2010 that tongue clicking was more 
successful than snapping or clapping. And in 2011, a study led by David 
Whitney of the University of California at Berkeley found that six blind 
echolocators with at least 10,000 hours of echolocation practice had a 
spatial precision that was "comparable to that found in the visual periphery 
of sighted individuals."

New technology could enhance human sonar further.

In 2009, a research collaboration including a group at the Polytechnic 
University of Valencia, Spain, unveiled a helmet that takes real-time images 
of the world, distills essential information out of it, combines it with 
depth data from a laser range-finder, and presents that information as audio 
cues  through headphones. This is essentially an enhanced version of human 
sonar - one augmented by technology.

Similar projects have popped up elsewhere.
The SmartCane is a combination cane and ultrasound system that sells for 
approximately $50 in India. And Tacit is a similar, open-source project from 
inventor Steve Hoefer, which translates distance information into haptic 
feedback - vibration on the user's hand.

Some of the most impressive research in this arena, meanwhile, comes from 
the laboratory of Amir Amedi, a neuroscientist at The Hebrew University of 
Jerusalem. Amedi's group has developed a program called EyeMusic that 
essentially translates images into short musical pieces.

And in 2012, the group showed that blind people can use this program to read 
letters and even recognize facial expressions - after only tens of hours of 
training.

How does it work?
The software that Amedi's group has created scans an image from left to 
right over the time of the musical piece. The higher the pixel in the image, 
the higher the pitch that is played, and different colors are represented by 
different musical instruments. Here are some examples:

(no direct link to EyeMusic video available)

EyeMusic is currently available as an app from the iTunes store, if you'd 
like to check it out.

And interestingly, these participants' brains used what has been previously 
thought of as visual areas when doing these tasks. "The input is arising 
through the ears, but then being delivered into the visual system," says 
Amedi, which suggests that these are task-related brain areas, not 
vision-specialized brain areas.

In 2014, Amedi introduced the EyeCane, a small, handheld device that uses 
two narrow infrared beams to detect nearby obstacles and translate them to 
either sound or vibration - depending on the user's preference. It was 
intuitive enough to require almost no training, and people could use it to 
detect an open door about 15 feet away.

Going further still: Using sound to see the world in ultraviolet.

This technology won't just benefit the blind. Amedi says his lab is also 
exploring the possibilities of using this technology to help people "see" 
through walls (by sensing infrared).
And artist Neil Harbisson has already used similar technology to give 
himself essentially superhuman capabilities.

Harbisson was born completely color-blind, with only grayscale vision. But 
he now has an sensor implanted in his skull that detects the colors of 
nearby objects and translates them into different musical notes produced by 
a chip in his head. That helps him "see" the colors of the world around him.

But the color sensor also picks up things that no human can naturally see - 
light in the ultraviolet and infrared ranges. So this means, for example, 
that Harbisson can sense the invisible infrared signal of a TV remote or 
motion detector.

Here's his incredible TED talk from 2012:

https://www.youtube.com/watch?v=ygRNoieAnzI

So human sonar might not just help restore sight to the blind. One day, it 
could end up allowing everyone else to see things they've never been able to 
see before.

Source URL:
http://www.vox.com/2014/11/7/7171119/blind-sonar-echolocation

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