[MUSIC PLAYING]
[CHEERING]
Few of us think about the trauma we generate in our voice boxes
when we talk, sing, laugh, or scream.
[CHEERING]
But take a look down the talented gullet
of Steven Tyler, Aerosmith's lead singer--
[SINGING]
--and you get a feel for why he, and millions of others,
are wreaking havoc on a delicate instrument.
OK.
[INAUDIBLE]
Tonight, as Aerosmith performs, Dr. Stephens Zeitels
and his team from Massachusetts General Hospital,
will get a rare treat.
Yeah.
With the help of special monitoring equipment,
they'll see how this famous pair of vocal cords
holds up to such extremes.
Doctors Zeitels, one time for my kids, what do you--
what do you-- what is this monitoring?
What we're going to be doing is looking at the vibrations
on the skin of your neck, which is going to pick up
the intensity of your voice.
Mm hm.
It's going to be picking up the loudness of your voice.
Mm hm.
Thank you, doctor.
Thank you.
Into the abyss.
[THROAT CLEARING]
Oh.
Into the great beyond with doctor Zeitels.
And that one--
Backstage, throughout tonight's concert,
Zeitels will use an endoscope to examine Tyler's voice
box up close.
[INAUDIBLE]
Try not to touch the sides.
Yup.
[THROAT CLEARING]
That's great, Steven.
Put your tongue out for me.
Just breathe.
Say hee.
Heee--
It's a rare insight into what goes on in a high performance
singer.
Mm.
Eh.
Real-time measures of a performer,
who is at the top of his game doing a live performance
for thousands of people.
It's a first.
It hasn't been done before.
[SINGING]
To produce these kinds of sounds,
Tyler's vocal chords are slamming together an average
of 170 times a second.
Ah.
That's more than half a million times
during the course of a concert.
Ah.
And nearly a billion times during the course
of his 30-year professional career.
There's no part of the human body that
likely sees these kinds of collision forces and shearing
stresses, which is why vocal folds essentially wear out
over time.
It's also why, just months earlier, damaged vocal chords
canceled much of Aerosmith's tour.
Tyler could barely sing--
[SINGING]
Just breathe.
--forcing him to undergo Zeitels' knife.
Or laser, in this case.
Stephen basically had a vocal bleed, which
is very common in performers.
Common, in fact, to many with the gift of gab.
From attorneys to telemarketers.
The laser surgery, which Zeitels and his team pioneered,
works by sealing off damaged vessels to stop the bleeding.
These aren't some Photoshop tricks you're looking at.
This is Steven Tyler's voice box.
And these are his fragile blood vessels disappearing.
He was able to zap those blood vessels.
So I go out there and just sing and hope for the best.
[MUSIC - AEROSMITH, "DREAM ON"]
Now, as Stephen heads on stage, his finely tuned vocal chords
spring into action.
And we get a front row seat.
This is Steven Tyler outside--
Anytime that I look in the mirror--
--and in.
Anytime that I look in the mirror.
All these lines on my face getting clearer--
Every time we exhale, we force air
through our two membranous vocal chords.
When we bring them together they vibrate.
Dream on.
These vibrations produce sound, much like a guitar string
after it's been plucked.
Dream on.
Muscles open and close the chords,
and change the sound's pitch.
Dream until your dreams come true.
During low notes, the chords are loose and vibrate more slowly.
Dream on.
But for those falsettos--
Dream on.
--his chords stretched to the limit--
Dream on.
--and vibrate, virtually, off the charts.
A surprisingly simple feat for Tyler's pliable chords.
I mean to go from, and woke up this morning
on the wrong side of the bed.
And all them things you said, and all the things I
said, but-- and it's in that voice.
And then, you know, of course, and I
don't want to miss a thing, is in that voice,
and then Dream On is Dream on.
Dream on.
And they've asked me before, how do
you sing that song every night?
Well that's one of the easiest ones for me to sing.
[SINGING]
As for what translates these vocal vibrations into song,
that happens much farther up in the throat, the mouth,
the tongue, the nose.
These are what put the stamp on a human sound,
distinguishing the likes of Steven Tyler from just
about anyone else.
[MUSIC - AEROSMITH, "LOVE IN AN ELEVATOR"]
Bettin' on the dice--
After some two hours of vocal gymnastics,
initial data reveal that Tyler's chords
crash together more than half a million times--
I really need a girl like an open--
--and covered the equivalent of more than six miles.
[CHEERING]
And there's no indication they'll
be wearing out anytime soon.
[CHEERING]
Thank you!
[CHEERING]
Dramatic as it may be, singing is a side effect
of a much more crucial process.
The real reason why air passes through our mouths
is breathing.
[CAR HONKING]
[BREATHING]
We wouldn't survive much more than a couple of minutes if we
didn't.
[BREATHING]
With every inhale, our noses or mouths
suck in about a pint of air some 20,000 times a day.
We can follow it on its journey down the throat, passed
the voice box, and into the windpipe, or trachea.
As it approaches the lungs, air has a choice.
Left or right?
But both lungs lead to the same end.
The lungs' bronchi divide and divide
into thousands of smaller and smaller branches, progressively
filtering chemicals, dust, and smoke in the air,
until, finally, they come to an end in this pouch-like ball
called, an alveolus.
[MUSIC PLAYING]
More than 300 million of them spread across each lung
with a combined surface area roughly a third the size
of a tennis court.
In less than a second, oxygen molecules
exit the lungs here through walls just one cell thick.
They'll then cross into a surging bloodstream,
be whisked throughout the body, and provide precious resources
to every one of our trillions of cells.
Assuming air gets to this point.
The blue, here, shows how a healthy lung empties oxygen
into the bloodstream.
In this smokers lung, oxygen can't empty nearly as well.
Then there's the exhale.
Carbon dioxide, the waste product of breathing,
makes the opposite journey back out.
Another inhale and our breathing apparatus
offers yet another gift with delightful or disgusting
results.
With every new breath, our noses can
distinguish as many as 10,000 different odors.
Some pleasing, some not.
They can calm, caution, or make our mouths water,
but the essence of any aroma, from a day
at the beach to fresh baked bread, is pure chemistry.
Isobutyl acetate, vanillic acid, and more than 300
different chemicals, for example,
come together to give chocolate its unmistakable bouquet.
A rose, by any other name, might be phenol ethyl alcohol.
And once fish is passed its prime,
it owes its stench to trymethylamine,
a byproduct of the bacteria growing inside it.
Whatever the chemical, deep inside our noses,
there is a small patch of about 10 million cells waiting
to sniff it out.
These cells carry about 1,000 different kinds
of receptors on their surfaces.
When the right odor chemical meets up
with the right receptor, an electrical signal
gets sent to the brain.
And finally, the incredible machine, smells.
All in all, our respiratory systems
are ingenious multi-taskers, sorting thousands of smells
at each intake.
Capable of making thousands of sounds on the way out.
But no matter how pleasant the by product,
there is a higher calling to breathing.
Every breath we take delivers oxygen
to our trillions of power hungry cells
and gets our hearts to pump.
[HEART BEAT]