How do stringed instruments make sounds?｜Brains On! Science podcast for kids

You're listening to Brains On, where we're serious about being curious.

Brains On is supported in part by a grant from the National Science Foundation.

Hey, Mark here with Ellie.

Hi everyone. Normally it would be Molly and our wonderful co-host Ellie, who would start the show, but Ellie just arrived at Brains On HQ and Molly has nowhere to be found.

Yeah, so we're going to find her.

We already searched all of her regular spots.

We checked Molly's office, Sandin's wildflower garden, Molly's other office that she keeps specifically for snacks.

Hey, Mark, what about this room?

Oh, that's the Brains On Workshop.

Maybe Molly's working on a project.

Let's take a look. Wow. Holy, super sized spider webs.

There are strings everywhere.

All my tools are tied together.

There's piano wires stretching from the ceiling to the floor.

Are there bands on the chairs?

Ellie, this is a little embarrassing.

It's not usually like this.

I like my workspace as nice and tidy.

Molly, are you in here? Who's that?

What time is it? Oh, oh gosh.

It's finally to me, Ellie.

It's fourth new break. Oh, Ellie, you're here.

With Mark. Hi, I'm so sorry I've been doing some string theory research and I was up all night.

Ellie took a really long nap under Mark's work table and...

String theory, like from physics?

What? Physics? No, no, no.

My string theory is the idea that you can make an instrument out of any kind of string.

I'm close to a real breakthrough but I will admit that string cheese has been a little tricky.

Good thing we're talking about stringed instruments on the show today.

Yeah, pretty convenient.

Let's go, Ellie. I just need to make a quick stop to grab a blueberry scone from my snack office.

Wait, but all my tools are still tied together.

And there's dental floss wrapped around all the cabinets and...

Molly, did you eat all my string cheese?

Gotta go, bye Mark. You're listening to Brains on from APM Studios.

I'm Molly Bloom and I'm here with my co-host, Ellie, from Toronto, Canada.

So glad you're here, Ellie.

Hi. Me too, Molly. I think you might have some silly string in your hair.

Oh, yep. I got it. Thank you so much.

So, Ellie, you sent in a great question to us.

Please remind us what it was.

I wanted to know how stringed instruments make different sounds.

Excellent question. So what made you think of this question?

I was playing my harp and I noticed that some strings have more of a twangy rubber band sound, whereas some are more slightly more musical.

Oh, interesting. So you play the harp?

Yes, I do. And you brought it with you today, right?

Yes, I did. So, Ellie, can you play the string that you think sounds a little more rubber bandy twangy?

And then can you play the one that you think sounds more musical?

Hmm. So is it that the twangy one is that little higher?

Is that why it sounds like that, do you think?

I don't know. I just think it sounds more like a rubber band.

Okay. So can you just play a little bit of the harp fresh as a song that you like to play?

Sure. Hmm. That's very beautiful.

So, I mean, it's a gorgeous instrument, but what made you want to play the harp?

My mama suggested it to me.

I did some research on it.

I thought it sounded really beautiful, and I thought it would be fun to try to play.

And I've really enjoyed it.

How long have you been playing it for?

I'm pretty sure I started when I was eight.

Okay. And how old are you now?

I'm ten. Okay. It's been a couple years.

That's amazing. It sounds so good.

I guess we should learn first a little bit how you get the harp to make different notes.

So, all along the harp, there are different strings.

Gotcha. Can you play the lowest note for me?

Okay. You'll play the highest note.

Ooh. That's a big range.

Are there like exercises or warmups you do on the harp?

Yes, there are. Can you play one of those, Russ?

Ooh. That's very soothing.

I could listen to you do that all day, but I suppose we have an episode to tape.

So, I guess we'll stop for the time being, but maybe later you can play me some more.

Well, to really understand how incredible the world of stringed instruments is, I think we need to start with what I like to call the wiggle wave.

Ooh. Is that an interpretive dance?

Are we waving kind of worms?

Is it a warm dance party?

That sounds fantastic, but I'm actually talking about stringed instruments making wiggles in the air.

Like I always say, moving air around is the key to sound.

Let me give you an example.

Let's see. Ooh. Okay. Here's a rubber band.

I'm going to stretch it out between my two pointer fingers.

Now, Ellie, grab one side of the rubber band and give it a little pull.

Okay. So you heard that sound, right?

When you pulled back the rubber band and let it go, it moved back and forth really, really quickly in a wiggly wave motion.

Here. Let's try it again.

Yeah. I can see the rubber band going up and down really fast when it wiggles.

As it goes, blowing in back and forth, the band pushes against the air around it, pushing it outward in the same wiggly wave pattern.

Those wiggly vibrations push more air and on and on until those sound waves get to your ear and you hear...

It's like the sound of the rubber band is touching my ear through the air.

Yeah. And the bigger the sound waves are, the louder the sound.

The smaller the waves are, the quieter the sound.

That's volume. Okay. But what about different notes?

That's not the same as how loud or quiet a sound is.

Right. This note is different from this note.

Even if they're the same volume.

The two notes are different pitches.

Pitch is whether a note sounds higher or lower.

Like these notes on the cello.

They're low. Low sounds make waves that are long and far apart.

Whoa. That's super low.

So those are some really wide waves.

Higher sounds make waves that are much closer together.

Yeah. Like these high notes on a guitar.

How about a kazoo? Technically, a kazoo doesn't have strings, but will allow it.

Wait. That's a great idea.

Where's my string theory research book?

And strings to kazoo? Question mark?

Fantastic. So instruments make sound by creating invisible waves in the air.

The volume of the sound depends on how big or small the waves are.

And the pitch is how close together or far apart the waves are.

Speaking of sound waves, we've got some very tricky ones coming your way.

It's time for the... Mystery sound.

Are you ready for the mystery sound, Ellie?

Yes. Here it is. Whoa. What was that?

What do you think? To me, it kind of sounds like someone's spinning a top or rolling a die on top of like a guitar.

Ooh. I love that. Yeah. I have no idea what this is either.

So I am stumped. Should we hear it again?

Yes. Okay. What do you think now, any new thoughts?

I don't... I think I'm going to stick to my original guess.

Yeah. I think top is a great guess.

I'm very impressed with whoever spun that top though, because it lasted forever.

It did. It's a very good top spinner.

Alright, well, we will hear it again, get another chance to guess, and hear the answer after the credits.

So stick around. We love hearing from you.

We love getting your questions, mystery sounds, and high fives.

You're all so curious and smart.

And something that we find extra super duper delightful is when you send us your artwork inspired by the show.

Maybe you want to draw a picture of my snack office or an instrument petting zoo?

You can send us your drawings at brainson.org slash contact.

And while you're there, you can send us mystery sounds, drawings, and questions.

Like this one. My question is, why do hot sauce make your nose run?

You can find answers to questions like these on the moment of um podcast.

It's a daily dose of facts and fun every weekday.

You can find it wherever you listen to brains on, just search for a moment of um.

So keep listening. Brainson Universe is a family of podcasts for kids and their adults.

And since you're a fan of brainson, we know you'll love the other shows in our universe.

Come on, let's explore.

And to bring brainson universe.

Ooh, so many podcast. Brainson.

Smash boom best. Forever ago.

Oh, picking up signal. Forever ago.

A history podcast starring Joy Dolo.

Flears gum was so sticky when the bubble popped.

It was so hard to get off your skin.

You'd have to scrub it off with harsh chemicals.

Me loves sticky facts. Swarp signal.

Quick need for forever ago.

No. Search for forever ago wherever you get your podcasts.

Buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, brainson.

You're listening to brainson.

I'm Ellie and I'm Molly.

And we've been talking about how stringed instruments make sounds.

It starts when you pluck or strum or bow a string, which makes that string vibrate or wiggle.

Those wiggles from the string push on the air around it and make that air wiggle too.

That makes a sound wave which travels to our ears.

And speaking of sound waves, we asked all of you to make some waves by recreating the brainson theme song.

Check it out. Buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh Buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh Buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh, buh Wow, many thanks to Gavin Cooper Carter, Charlie Asher, Mia Caleb, Lucy Eddie, Whalen, and Roxy for those incredible renditions.

I am in awe of your magical music minds.

So good. Uh-huh, yeah, Ellie's here with me and we're talking about stringed instruments.

Why? I'm feeding the instruments of the petting zoo.

You want to come by? Feeding time?

At the instrument petting zoo?

Heck yeah, we'll be right there.

Come on, Ellie. Brains, brains, brains.

Here we are. Hey, Molly, hi, Ellie.

I'm so glad you're here.

Hang on, just let me wash my hands.

Feeding the trombones always gets so messy.

That's better. Welcome to the instrument petting zoo.

It's just a room of lots and lots of instruments laying on the floor.

Just instruments? These are my prized instrument herds.

All free range, well trained and totally pampered.

And when the herd and I heard you were going to be talking about stringed instruments, I wanted to show them off.

Anna's ukulele won first prize at the fair last year.

See, it's got a blue ribbon on it.

Wow. Ellie and I were just talking about how strings make sound waves in the air.

And how we hear the sound waves as notes.

They can be higher or lower and louder or softer.

But I still want to know why instruments sound different from one another.

That's a fantastic question.

Another one of my string theories is that it depends on what you feed your instruments.

A well fed instrument always sounds better, right Anna?

Oh, only the best diets of healthy whole notes for my little orchestra.

But really it's all about how each instrument bounces those sound waves around.

Instruments have different shapes and are made of different things.

All of that can change the sound they make.

Yeah, my harp and your guitar are really different shapes and sizes and they make really different sounds.

Exactly. Here, let me show you with my acoustic guitar.

Come here, baby. Yeah. So an acoustic guitar usually has six strings and a hollow body made out of wood.

The strings start at the top of the neck.

That's where you press down to make different notes.

And at the other end of the guitar, the strings are stretched over a thin piece of wood called a bridge that helps pass vibrations into the guitar.

You can pluck the strings and it sounds like this.

Or you can strum them like this.

And there's a hole right in the middle of the guitar underneath where you strum it.

Another one of my string theories is that strings make better sound waves if you compliment them regularly.

And also if the sound waves can bounce around a lot.

And bouncing is exactly what's happening.

When I play the strings, they vibrate throughout the guitar and through this round hole in the middle called the sound hole.

And then they keep bouncing off the walls inside the guitar?

Yeah, it's kind of like when you yell into a tunnel.

You know, I love to yell.

Your voice makes sound waves that bounce around the tunnel and you hear the echoes all coming back on top of each other.

So the inside of the guitar is like the inside of a tunnel, bouncing sound waves around.

Yes, and the sound waves come back out of the sound hole making a bigger, rounder and fuller sound than just the strings twanging on their own.

The shape of an instrument and the stuff it's made from can totally change how those strings sound.

How? I'll show you. How about we play a little guessing game?

I'll play three of my beautiful instrument buddies for you.

You can try to figure out which instruments are making the sounds and then I'll tell you how their shape and how they're made influences the sound.

Molly and Ellie, are you ready?

Yeah. Yeah. Okay, here's instrument number one.

That was fun. What do you think, Ellie?

I think that was the sound of maybe a banjo.

Yeah, kind of have that sound like someone strumming strings kind of like a guitar.

Is that like between a guitar and a banjo?

But not really ukulele.

Yeah, I agree. Okay. More of a country sound.

More of a country sound.

I'm gonna go with a tiny guitar that's not a ukulele.

Why are we right? So you were right on the money with your thought that maybe it was kind of country because this instrument is used in country and bluegrass music a lot.

That was a mandolin. What's a mandolin, Anna?

I've never heard of it before.

Well, a mandolin is an instrument that's around the same size as a violin so you can hold it pretty easily in one hand.

And the body of it is kind of a teardrop shape.

And it's got four notes like a violin.

It's tuned like a violin.

But each note is played by two strings.

So there are pairs of strings.

And it gives it that kind of full sound, that nice round sound that you heard.

But it makes it really tricky to tune.

All right, will you please show us instrument number two?

Wow. That was deep. What do you think, Ellie?

It sounded kind of like maybe like a cello.

Good guess. I think it sounds even deeper than a cello.

Is it a bass? What does it call it a bass?

Like the one that stands upright?

Like a really big cello?

Yeah, you nailed it. It is an upright bass.

So those are some big, big wide sound waves because the notes were so low.

So I want you to picture a violin with that kind of figure eight shape and the F-shaped holes in the body and then the neck and the tuning pegs.

And then I want you to imagine that that violin is six feet tall because that's how big a string bass is.

Whoa. That's very tall for instrument.

All right. Are you ready for instrument number three?

Yes. Yes. What do you think, Ellie?

I hear guitar sounds, but then again, I also hear like high pitch buzzing like a trumpet.

I also hear metal clicking, so I don't really know.

Yeah, those are really good observations.

I think I have an idea which is this.

Okay. Is this an instrument from India?

It is. Tell us what it is.

That was the sound of a Cittar.

The Cittar is a plucked string instrument that's related to a lute and it's about four feet long and you play it sitting down with the body in your lap.

The body is kind of a pear-shaped gourd and it's got a long wide neck that you kind of hold up at an angle and play.

And Cittars can have between 18 and 21 strings and that's because some of the strings are for plucking and some lined up underneath the plucked strings are sympathetic.

That doesn't mean they'll sit and listen to your problems.

The sympathetic vibration is when a sound or other type of wave passes from one object to another.

So when the Cittar player plucks the top strings that are stretched over these high curved wooden bridges that hold them up off the body of the instrument, the sound waves also travel to the strings underneath and those vibrate a little bit and that makes that twangy echoey sound that you heard.

That's so cool. That's amazing.

Yes, it's fun. Thank you both so much for playing with me.

Thank you, Anna. That was so fun.

And I think this proves my biggest string theory of all.

String instruments are wonderful because they make so many amazing sounds.

What a breakthrough. Maybe now I can finally make the string cheese harp I've been dreaming of.

Where's my notebook? Stringed instruments push air into wiggly sound waves which travel to our ears.

Loud sound waves are made up of big wiggly waves and soft sounds are made up of smaller wiggly waves.

The pitch of a sound is how high or low it is.

And stringed instruments sound different from each other because of the different tools used to hit, pluck or play them.

Plus the size and shape of their box.

That's it for this episode of Brains on.

This episode was written by Anna Goldfield.

It was produced by Molly Bloom and Rosy DuPont.

Our editors are San and Ton and Shala Farzon, fact checking by Ruby Guthrie.

We had engineering help from Gary O'Kee, Derek Ramirez, Lucien Lozon and Bill Walker with sound designed by Rachel Breeze, original theme music by Mark Sanchez.

We had production help from the rest of the Brains on universe team Anna Goldfield, Nico Gonzalez Whistler, Lauren Humpert, Joshua Ray, Charlotte Traver, Anna Weggel and Audorone Waldice-Lassie.

Beth Peroman is our executive producer and the executives in charge of APM Studios, our Chandrakavati and Joanne Griffith.

Special thanks to Jonathan and Diane Scarlett.

Brains on is a nonprofit public radio program.

There are lots of ways to support the show.

Subscribe to Brains on universe on YouTube where you can watch animated versions of some of your favorite episodes or head to brainson.org.

While you're there, you can send us mystery sounds, drawings and questions.

Speaking of mystery sounds, Ellie, are you ready to hear that sound again?

Sweet. Nice. Okay. What do we think?

I'm still sticking to my original guest.

The die or the top rolling or spinning on top of a guitar or a table.

I love that guest. I have no idea.

So I'm going to stick to your guest too.

Let's hear the answer. Hi, my name is Agdor from Agdor, Georgia and that was the sound of my top spinning.

Oh my gosh, Ellie. You did it.

You got it right. How does that feel?

Great. Awesome. Have you spun tops before you must have?

Yes, I have. Can you spin your tops as long as Edgar can because that was pretty impressive Edgar?

No. The tables in my house have like cracks on them for the wood as a design.

So they always get stuck on them.

Okay, we need a better surface for you.

Wow. Good, guessing, excellent ears.

Now it's time for the brains honor roll.

These are the incredible kids who keep the show going with their questions.

Ideas, mystery sounds, drawings and high fives.

Baker from Bremerton, Washington, Sebastian from Inververy, Scotland, Caden and Hunter from Belgrade, Montana, Aurora and LaDee from Charlotte, North Carolina, Anya from Newberg, New York, Adina from Toronto, Jack from Mesa, Arizona, Peter from Windsor, Wisconsin, Millie from Los Angeles, Orion from Portland, Oregon, Kai from Honolulu, Kora and Jody from the Bastapold, California, Ferris from New York City, Adeline from Raleigh, North Carolina, Phoebe from Beijing, April from Marano Valley, California, Francis and May from Camloops, British Columbia, Olive from Vancouver, Washington, Salome from Lebanon, New Jersey, Hazel from San Diego, California, Gabriel from Brooklyn, New York, Nico from Austin, Texas, Axel from Winnipeg, Shoshana from Leander, Texas, Amelia from Milwaukee, Iowa, Juni from Queens, New York, Otis from Mill Valley, California, Florence from Courtney, British Columbia, Hania from Louisville, Kentucky, Kitt from Massachusetts, Levi and Owen from Santa Clara, California, Anson from San Marino, California, Fred from Coppets, Switzerland, Grace from Ontario, Riley from Rochester, New York, Beebe from Baltimore, Marcus and Everett from Dallas, Yusef from Cairo, Egypt, Ray from England, Chloe, Evan and Caleb from Omaha, Dominic from Papalon, Nebraska, Elliott from Melbourne, Australia, Greenlee from Calgary, Avery from Milwaukee, Iowa, Decker from Northfield, Minnesota, Luke and Elijah from Coco Beach, Florida, Narelli from Delaware, Ohio, Alyssa from Oakville, Ontario, Allie from Colorado, Savion, Calif and Jürner from Oakland, California, Andrew from Pierce, Minnesota, Jocelyn from Monkton, New Brunswick, Titus from Sacramento, Olive and Remi from Candler, North Carolina, Zara from San Francisco, June from Hyde, British, Germany, Miles from Alameda, California, Olan and Enzo from Missouri, City, Texas, Rosie from Austin, Texas, and Corbin from Burian, Washington.

We'll be back next week with an episode all about vacuums.

Thanks for listening.

[현악기는 어떻게 소리를 낼까? 파동과 울림의 과학]-[How do stringed instruments make sounds?]

📋 Summary

현악기의 원리: 파동과 진동의 세계

1. 소리의 탄생: '흔들리는 파동(Wiggle Wave)'

2. 악기마다 다른 소리가 나는 이유

3. 결론: 악기는 과학의 산물

🎯Key Sentences

📝Key Phrases

📖 Transcript