Last time: warming
oceans and real
risks. Today: a
little sensory
wonder!

Fernanda, keep an
eye on the audience.
I only have two.

Fernanda

What we see. 
What we hear.
And all the things
happening beyond
our senses.

Our senses are
useful windows—
not the whole
universe.

Our eyes see roughly
380–740 nanometers of light.
The boundaries are
gradual, not sharp.

Priscilla, that is a
very stylish little
slice.

Priscilla

Reminder:
Koru Brain
Antenna

Our eyes use
light-sensitive
cells; cones help us
distinguish colors.

Evolution shaped
that toolkit. Useful
does not mean
unlimited!

Beatrice sees
ultraviolet patterns
on flowers that I
cannot see.

Those patterns can
help guide bees to
food. Beatrice gets
the secret menu.

Beatrice

Percival detects
infrared warmth with
specialized facial
pits—not ordinary
color vision.

Different sensor.
Same excellent
question: where is
dinner?

Percival,
pit viper

For young, healthy
ears, the usual
hearing range is
about 20 to 20,000
hertz.

Hertz means
vibrations per
second: low to high
pitch. Not quiet to
loud!

Inside the cochlea,
different places
respond best to
different pitches.

Higher pitches
toward the base;
lower pitches
toward the tip.
A tiny biological 
sound sorter!

That upper limit
often falls with
age, and noise
exposure can damage
hearing too.

There is no exact
birthday when
everyone loses the
same note.

WHO TURNED ON THAT
LITTLE PIECE OF—

Binky of Balance,
would you kindly
quiet him before
he finishes that
sentence?

Binky of
Balance

What
noise?
Finally.
An age-related
advantage.

Different ears,
different limits.
Same family.
Very different
reviews.

Grand
Relative

Eunomos

Bart sends out
ultrasonic calls and
listens to the
echoes.

Much of that sonar
is above our
hearing. His dinner
comes with a
distance estimate.

Bart, 
echolocating
bat

Rumbleton uses very
low-frequency
rumbles, including
sounds below our
usual hearing range.

Elephants can also
pick up vibrations
through the ground.
My feet mostly
report pebbles.

Rumbleton

Now I wonder: why is
the human voice as
loud as it is?

Decibels describe
sound level—not
pitch. And the level
you measure depends
on distance, too.

I picture Aro and
Neri trying to chat
while Patricia pours
down for ages.

No engines. No
factories. Just a
very persistent sky
drummer.

Aro, ancestor

Neri, ancestor

Patricia,
heavy rain

Did our ancestors
need voices louder
than rain?

It is a lovely
thought—but
imagining it does
not establish an
evolutionary
explanation.

And rain was not
their only lasting
noise: wind, rivers,
surf, waterfalls…

Fine, Wallace. You
were loud before
engines existed.

Wallace

Today we add cars,
aircraft, factories,
and fans to the mix.

Francis, you are
tiny. Why does your
entire personality
go whoosh?

Francis

There is real
evidence for the
Lombard effect:
competing noise can
make us speak
louder, and often
change pitch or
duration.

That is a flexible
response—not proof
our voices evolved
to beat rain.

Still, I like
imagining Aro and
Neri sharing stories
under a shelter.

A guess can start a
science question. It
can also just be a
happy little
daydream.

That is our sensory
adventure. Thanks
for seeing—and
hearing—me out!

Bye for now!
Fernanda, take a
bow.

Wait. One
ear-related
bonus!

Atlas and Indi
brought maps.
Apparently.

Atlas

Indi

African elephant
ears can look a bit
like Africa. Smaller
Asian elephant ears
are sometimes
compared to India.

Not exact maps—just a playful
resemblance! Atlas and Indi
make a fun little memory trick
for telling African and Asian
elephants apart.

Now I am really
leaving. Probably.

African 
elephant ear

Indian
elephant ear