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You may know that animals like bats and dolphins
can use sound to 'see' their surroundings.
It's called echolocation, and it's kind of like sonar.
They make noises that travel around them and bounce off nearby objects.
Their brains are actually able to translate the reflections of those sounds
into a kind of three dimensional picture of their surroundings.
Which is a pretty neat trick.
And, as it turns out, it's one your brain can perform, too.
That's right—humans can echolocate, thanks to our big, flexible brains.
It's just that we usually don't, because most of us can rely on our vision.
Most of the people who echolocate are blind,
and it helps them navigate what they can't see.
By making clicking noises that last a few milliseconds
and then listening to the reflected sound waves,
they're able to obtain information about the size, shape and texture of objects
as well as their distance from them.
And that allows them to build a mental map of their surroundings—
detailed enough for some that they can go hiking or even ride a bicycle.
The clicks can vary in volume and number as needed,
and are higher in frequency than normal speech.
Other echolocating animals use higher frequency sounds, too,
probably because they provide greater resolution,
even though they don't travel as far.
And human echolocators emit their sonar-like sound
in a focused, 60-degree 'cone of perception'.
Practice makes the clicks faster and sharper
than the clucking sounds you might make,
so they're more directed and the returning sounds are less muddled.
These clicks only detail what's in front of the echolocator, though.
When researchers prevent head turning, human echolocators have trouble
understanding their surroundings and are more easily disoriented.
And that's different from bats, which have rotating ears
to allow them to hear sound reflections from all around.
Echolocation in dolphins is a whole other thing,
as they use specialized fat deposits to focus their sounds
and basically hear with their whole heads.
And, of course, they just echolocate naturally—we don't.
Some blind people do sort of stumble into echolocation.
But relatively few navigate this way, even though it can be taught.
We don't know exactly why that is,
but experts suspect it's because most don't realize it's an option.
Even people who aren't blind can learn to echolocate,
though it takes time and not everyone who's tried is great at it.
Those that are may actually rewire their brains to quote "see" sounds.
A 2011 study used functional magnetic resonance imaging—
a technique which monitors blood flow to see brain activity in real time—
to compare the brains of two people with normal vision
to two blind echolocators: one who was blind from infancy,
and one who lost their sight as a teenager.
In both blind subjects, parts of the brain normally used for visual processing
were active during echolocation.
That suggests that those parts of the brain can get rewired
to "visualize" the world using sound instead.
But the study was small and it didn't compare sighted echolocators to blind ones,
so we don't know if similar changes can occur for everyone who learns the skill.
And unfortunately, most of the few studies examining human echolocation
have been similarly tiny, so our understanding of it is very limited.
Still, the fact that any people can echolocate at all
shows just how adaptable our brains really are.
And you're watching SciShow so I bet you like to
teach your adaptable brain new things.
Skillshare is an online learning community with over 20,000 classes
in video production, technology and pretty much anything you're interested in.
I was inspired by the idea of visualizing a space I've never seen before
and checked out this Concept Art course on drawing imaginary worlds.
Definitely not the same as echolocation,
but still a really cool, in-depth look at how one artist builds worlds.
If you want to drawing your own imaginary world, or pick up any new skill,
Skillshare is offering SciShow viewers 2 months of Skillshare for FREE!
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click the link in the description to sign up and start adapting your brain today!
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