00:00:09
Many creatures rely primarily on sight00:00:12
00:00:12
to understand their world.00:00:14
00:00:17
But what about when seeing00:00:19
00:00:19
is not enough or nearly impossible?00:00:21
00:00:22
Some animals use echolocation.00:00:24
00:00:26
They use sound to perceive00:00:28
00:00:28
what may not be able to be seen with eyes.00:00:32
00:00:32
Most bats have this ability.00:00:34
00:00:34
But making it work00:00:36
00:00:36
in the cluttered, crowded spaces
where they live00:00:39
00:00:39
is highly complex.00:00:40
00:00:42
They must constantly update their perception00:00:44
00:00:44
of the space around them.00:00:46
00:00:46
How?00:00:47
00:00:47
With the fastest muscle contractions
of any mammal,00:00:51
00:00:51
they fire rapid bursts of sound.00:00:53
00:00:53
Then they listen00:00:55
00:00:55
—not just hearing echoes but analyzing them.00:00:59
00:00:59
The timing of the echoes00:01:01
00:01:01
allows them to pinpoint objects,00:01:04
00:01:04
and astonishingly,
some bats, like the big brown bat,00:01:08
00:01:08
can distinguish details
less than a millimeter apart.00:01:12
00:01:12
A bat’s sound comes
from its throat or tongue,00:01:15
00:01:15
but a sperm whale’s sound
starts inside its massive head.00:01:19
00:01:19
Before diving, it fills its lungs with air,00:01:22
00:01:22
using some of it to produce underwater sounds00:01:26
00:01:26
that have been measured at 230 decibels,00:01:30
00:01:30
louder than a jet taking off.00:01:33
00:01:33
The whale00:01:34
00:01:34
forces air through a pair of phonic lips,00:01:36
00:01:36
causing them to clap or click.00:01:39
00:01:39
But instead of projecting forward,00:01:42
00:01:42
the sound first bounces off of an air sac00:01:44
00:01:44
and travels backward
through the whale’s spermaceti organ.00:01:48
00:01:48
After bouncing off of a second air sac,00:01:50
00:01:50
the sound then moves forward00:01:52
00:01:52
through a mass of tissue called the junk.00:01:56
00:01:56
This process focuses the sound
into a narrow beam,00:02:00
00:02:00
which the whale directs like a searchlight.00:02:02
00:02:04
A 40-ton whale can’t stop suddenly.00:02:06
00:02:06
These powerful clicks may help it00:02:08
00:02:08
to avoid crashing into the ocean floor
and other hazards.00:02:12
00:02:12
Closer to the surface,00:02:14
00:02:14
dolphins also rely on echolocation.00:02:17
00:02:17
Like other toothed whales,00:02:19
00:02:19
dolphins don’t use external ears
to hear echoes.00:02:23
00:02:23
Instead, they hear through their jaw,00:02:26
00:02:26
where specialized fat
conducts sound directly to their inner ear.00:02:30
00:02:30
Some dolphins can sense objects
more than 650 meters away.00:02:35
00:02:38
In open ocean, the deepest waters,00:02:40
00:02:40
and total darkness,00:02:41
00:02:41
some animals are able00:02:43
00:02:43
to “see” with sound
—and with tremendous precision.00:02:46
00:02:47
Could this amazing capability have evolved?00:02:50
00:02:51
Or was it designed?00:02:53
Was It Designed? Echolocation
-
Was It Designed? Echolocation
Many creatures rely primarily on sight
to understand their world.
But what about when seeing
is not enough or nearly impossible?
Some animals use echolocation.
They use sound to perceive
what may not be able to be seen with eyes.
Most bats have this ability.
But making it work
in the cluttered, crowded spaces
where they live
is highly complex.
They must constantly update their perception
of the space around them.
How?
With the fastest muscle contractions
of any mammal,
they fire rapid bursts of sound.
Then they listen
—not just hearing echoes but analyzing them.
The timing of the echoes
allows them to pinpoint objects,
and astonishingly,
some bats, like the big brown bat,
can distinguish details
less than a millimeter apart.
A bat’s sound comes
from its throat or tongue,
but a sperm whale’s sound
starts inside its massive head.
Before diving, it fills its lungs with air,
using some of it to produce underwater sounds
that have been measured at 230 decibels,
louder than a jet taking off.
The whale
forces air through a pair of phonic lips,
causing them to clap or click.
But instead of projecting forward,
the sound first bounces off of an air sac
and travels backward
through the whale’s spermaceti organ.
After bouncing off of a second air sac,
the sound then moves forward
through a mass of tissue called the junk.
This process focuses the sound
into a narrow beam,
which the whale directs like a searchlight.
A 40-ton whale can’t stop suddenly.
These powerful clicks may help it
to avoid crashing into the ocean floor
and other hazards.
Closer to the surface,
dolphins also rely on echolocation.
Like other toothed whales,
dolphins don’t use external ears
to hear echoes.
Instead, they hear through their jaw,
where specialized fat
conducts sound directly to their inner ear.
Some dolphins can sense objects
more than 650 meters away.
In open ocean, the deepest waters,
and total darkness,
some animals are able
to “see” with sound
—and with tremendous precision.
Could this amazing capability have evolved?
Or was it designed?
-