We have noses to smell,
eyes to see, and ears to hear, right?
眼睛用来看 耳朵用来听 没错吧？
Well, actually, your ears are responsible for much more than just hearing.
In fact, they can even help you taste.
And that’s all thanks to what’s inside.
We think of ears as these flappy appendages that stick out of our heads.
But the most important structures
are actually on the inside,
and they’re known as the inner and middle ear.
Iram Ahmad: Inside your middle ear is the nerve that moves the muscles of your face.
Narrator: Aka the facial nerve.
And if it becomes inflamed or injured,
say, from a nasty ear infection,
you can lose control of the muscles in your face.
But it could actually get worse.
Ahmad: Now, along that facial nerve there is a taste nerve.
It’s called chorda tympani.
Narrator: That’s right, the nerve for taste
runs right through your middle ear.
And if that nerve gets damaged,
you could alter or even lose your sense of taste permanently.
By the way, not only are your ears incredibly important for tasting food,
but what you’re listening to
can also change your food’s flavor.
For example, research has shown that
white noise can dull saltiness but enhance crunchiness.
And in one study, volunteers perceived
a dish to be eggier when they listened to the sound of clucking chickens.
But whether it’s the sound of chickens
or my beautiful voice,
it all enters your ear through the cochlea,
a shell-like structure in the inner ear.
Inside the cochlea there are over 16,000 hairlike cells,
which take vibrations entering your ear
and convert them into nerve impulses.
Those impulses travel to your brain,
which turns them into the sound you hear.
So if it weren’t for those cells, you’d be deaf.
Which is why it’s incredibly important
that you keep them protected.
Especially from menaces like bacteria, viruses,
and even adventurous insects.
And for that, your ears’ best defense is earwax.
为此 耳朵有一道最佳防线 那就是耳垢
Ahmad: Earwax is good.
It is not bad to have earwax.
Narrator: That’s right. You need that gross, golden wax.
It not only has antibacterial properties,
but it’s also downright sticky,
helping to stop invaders right in their tracks.
But earwax isn’t the only part of your inner ear
that keeps you healthy.
Ahmad: So, there is a tube made of muscle
that connects the back of your nose and your ears.
Narrator: It’s called the eustachian tube,
and it helps equalize pressure
between your ears and the atmosphere around you.
Normally the tube is sealed off
so nothing can travel between your ears and your throat,
which keeps infections at bay.
But when there’s a change in pressure,
like when you’re taking off in an airplane,
the air inside the tube expands.
Which typically makes you want to pop your ears.
And that’s a good thing too,
because popping your ears
opens the tube and releases the air,
balancing the pressure inside and out.
Speaking of balance, there’s one other incredibly important structure
you can find inside your inner ear:
the vestibular system.
Kind of like a level, it controls your balance
using a number of liquid-filled canals.
Ahmad: Those balance canals are responsible for telling your body you are moving.
Whether it may be moving left to right
or your body’s moving up and down.
Narrator: As you move around,
fluid in the canals sloshes against millions of hairlike structures,
it’s called stereocilia,
and this sends a signal to the brain
where you process it as movement.
That’s why infections like the common cold
can sometimes make you feel dizzy.
They often cause inflammation in the vestibular nerve,
which distorts those signals.
So the next time you find yourself
walking without falling over,
or tasting your food,
or listening to, well, anything,
think of your ears.
Which, as it turns out,
have a lot more going on inside than out.
We have noses to smell,