and you know what's amazing?

Magnets.

But we are not here to talk about magnets today.

Instead we are gonna talk about an instrument that we all have;

which is our throat

And then we are also gonna talk about ears,

which isn't really an instrument.

But let me show you this clip.

(Clip plays) (People singing)

That is called tuvan throat singing or

Khoomei,which is an ancient Mongolian technique of

singing two tones at the same time.

And we can do it too with the power of DONGS-

things you can Do Online Now Guys.

(Intro Music)

Pink Trombone was featured in a previous DONG,

but there is even more to talk about.

If we hit the pitch wobble button, it

will hold a single note.

If we right click anywhere, we can keep it from snapping back to its original shape.

So then we will make a little

cave with the tongue and use the front of the tongue to change the shape of the cave.

Bam! You're singing two notes!

But how does this actually work?

Well it comes down to how we pervieve and create tones.

Whenever we hear a tone we're hearing the main note.

Also called the fundamental.

And then a bunch of other notes on top of it called overtones.

Tones are the frequencies we hear

and notes are the same name we give to them, so this

[PITCH PLAYING] So this is a tone, but calling it a 'G' makes it a note.

Anyway, what these singers are doing is isolating the overtones with their tongue

and amplifying it with their lips

causing a two tone whistle now pudding.cool has a great visualizer on

overtones; the brighter a sound is the more overtones it has. Bright sounds are

things like a distorted electric guitar or a square wave or a raspy voice so

here we start with a sine wave and then we add the overtones on top and it gets

brighter and brighter. At first it sounds like real notes but as they get higher

and higher they just start to sound like buzz. The overtone series is why some

chords sound good together: they reinforce the harmonic series.

We can see this with the overtone generator website which lets you hear each relationship

between notes in the overtone series. Each bar changes the volume of a

multiple of the fundamental frequency. You can also see what different types of

waves look like, and what overtones each of them use.

Here's square, sawtooth, and a simplified version of a violin.

At the online tone generator we can check out alot of cool stuff with tones.

When you set it to one Hertz, do you hear the beat?

Now let's speed it up and it eventually becomes a note.

This means notes are just really fast beats, and beats are just really slow notes.

If we go back to the overtone generator we can see something interesting.

Any combination of notes can be thought of as a ratio

where each number represents the relative Hertz of each tone.

So this chord you're hearing has a relationship of 5/4.

Now remember that a tone we hear is just a really fast beat, so these two tones represent a poly-rhythm.

For every five beats of one there's four of the other

and that gives us a nice pretty major chord.

The thing is, our brains love simple math with small whole numbers.

As the numbers and the relationships get bigger and more complicated

they sound more and more dissonant and...kind of sour...off.

You can see this really clearly with the African polyrhythm generator.

This is essentially the same concept but slowed incredibly far down.

If you play the four beat and the five beat at the same time, well you're experiencing the same thing as a major third.

a nice happy note, a nice happy beat.

But if you bring the numbers up, it starts to sound a little crunchy.

You can also check out the page on binaural beats

which is an illusion that takes advantage of our brain's assumptions about what it's hearing

now, put on some headphones for this and play slightly different tones in each ear

and your brain will fill in the beat it assumes it should be hearing

So if we play a three hundred Hertz tone in one ear

and a three hundred one Hertz and the other, we will hear a pulse underneath it

At a rate of one Hertz; the difference between the two tones.

And if we go back to the regular tone generator and play that one Hertz beat again

it'll be about the same speed.

Normally when you hear two frequencies that are similar, but not exactly the same

the compressions of the air that cause the sound will cancel each other out

causing a beats and this is not an illusion it's actually how

sound and air compression work. This website also has a hearing test that

will sweep through all the hearable frequencies.

Normally the human ear can hear between 20 and 20,000 Hertz

but with age and damage to the sensory hairs in your inner ear

you may lose sensitivity to certain frequencies.

So let's turn up the volume

also Jack probably should have closed this tab...

that is inappropriate...

Alright so, we are going to play...

[PIANO MUSIC]

[PIANO MUSIC] What? Oh my gosh

you just have one hour of relaxing Zelda breath of the wild music on

[LAUGHING] Now I know what you listen to.

[LAUGHING] That really scared me

[RISING TONE]

Okay I can hear that.

Okay it's going up. We're hitting three thousand

Four thousand

Seven thousand. That's going to take a little while to get to twenty.

Eight thousand.

Can everyone still hear this?

[BACKROUND: Mh mhm] You sound so sad.

I feel like the dog is probably very upset.

Eleven thousand.

Twelve thousand.

I feel like I'm in one of those movies where the sonar is like

OH NO THEY'RE GETTING CLOSER!

Oh we're at fifteen. I can't hear it anymore.

Can you hear it? [BACKGROUND: Yea I can hear it]

We're now at seventeen.

Eighteen.

I can't hear anything. So I I dropped off at about fifteen thousand Hertz

the other folks in the room that aren't Jack or Jake were about

what seventeen thousand Hertz? What were you at? I wonder. But you know what let's

let's move to some a little bit more calming, with calming tones

this chill music maker has a bunch of ways to customize the sounds it makes.

You can choose the type of waves the tempo filters and effects.

Oh yea, I feel calmer already. Do we have any other calm music DONGS?

You bet your ding dong diddly we do.

At virtual halo player you can play around with a simulation of this space-y instrument

and a crazy amount of tunings.

[LAUGHING]

You just play with the numbers on your keyboard but just so you know, we don't just do

things online now guys here, no we don't. Barry White, do we?

Disinterested.

We also do things in real life now guys known as DIRLINGS

And also before we get into the DIRLING, if you want there's more DONGS

Right here in this playlist. That you can click. Next to my face. That's wonderful.

[TO THE SIDE] Barry White where are you going? He's so confused.

But now back to the DIRLING. Our wonderful VFX wizard and cinematographer here at Vsauce, Eric Langley,

is going to play a Halo drum that he loves very much

his name is Susan, is what he calls it he's playing an original song that he

wrote called doves fly through the air. And as always thanks for watching.