What Makes Sound? | Varsity Tutors

SECTION 1

What's Happening?

🔍 LOOK AT THIS!

When the rubber band stops shaking, the sound stops too. Isn't that interesting?

A rubber band stretched over a box, vibrating and making sound waves.

💭 THINK ABOUT IT

SECTION 2

Big Ideas About Sound

Sound is something we hear every day. But where does sound come from? Let's learn two big ideas!

1

Sound Comes from Vibrations

Vibrate means to shake back and forth very fast. When something vibrates, it makes a sound. You can sometimes see it shaking. You can sometimes feel it shaking!

2

No Shaking = No Sound

When the shaking stops, the sound stops too. If nothing is vibrating, there is no sound. The vibration and the sound go together!

✦ KEY TAKEAWAY

KEY TAKEAWAY

SECTION 3

Let's Try It!

Scientists learn by trying things out and watching what happens. That means you can be a scientist! Let's do a simple test to see if vibrating things really do make sound.

🔬 LET'S TRY THIS!

What you need: a rubber band, a ruler, and your hands

1

Step 1Stretch a rubber band between your fingers. Pluck it. Look at it and listen. What do you see? What do you hear?

2

Step 2Hold the end of a ruler on a table. Let part of the ruler hang off the edge. Push the hanging end down and let go. Look and listen!

3

Step 3Put your fingers gently on your throat. Hum a song. What do you feel?

Three investigation steps: pluck a rubber band, twang a ruler, and hum while touching your throat.

SECTION 4

What We Found Out

In every test we tried, we found the same thing. When something was vibrating (shaking fast), it made a sound.

When you plucked the rubber band, it shook and you heard a sound. When you pressed the ruler and let go, it shook and you heard a sound. When you hummed, your throat was shaking and you could feel it!

Investigation Results

What We Tested	Did It Vibrate?	Did It Make Sound?
🎸 Rubber band (plucked)	Yes! We saw it shake.	Yes! We heard a twang.
📏 Ruler (pressed down)	Yes! We saw it wobble.	Yes! We heard a boing.
🎤 Throat (humming)	Yes! We felt the buzz.	Yes! We heard our hum.
🤫 Rubber band (still)	No. It was still.	No sound.

Every time something vibrated, there was sound. Every time the vibrating stopped, the sound stopped. This tells us something important!

✦ KEY TAKEAWAY

KEY TAKEAWAY

SECTION 5

Do You See the Pattern?

Scientists always look for patterns. That means they look for things that happen the same way again and again.

We found a pattern! Every time something vibrated, there was sound. Let's see this pattern in more places.

1

A Drum 🥁

When you hit a drum, the top shakes. You hear a boom! When the shaking stops, the boom stops.

2

A Guitar String 🎸

When you pluck a guitar string, it vibrates. You hear music! When the string stops, the music stops.

3

A Bell 🔔

When you ring a bell, the metal shakes. You hear a ring! When the bell stops, the ring stops.

4

A Bee's Wings 🐝

A bee's wings vibrate super fast. That is why you hear a buzz!

✦ KEY TAKEAWAY

THE PATTERN

SECTION 6

Sound in Our World

People use what we know about vibrations and sound to solve problems and make cool things!

🎵 Musical Instruments

People build instruments like drums, guitars, and pianos. Each one has parts that vibrate in different ways to make different sounds. A big drum vibrates slowly and makes a deep sound. A tiny bell vibrates fast and makes a high sound.

📱 Speakers and Phones

When you hear your mom or dad's voice on a phone, a tiny part inside the phone is vibrating! It shakes the air, and you hear the sound.

🛠️ DESIGN CHALLENGE

SECTION 7

Word Bank

Key Vocabulary

Word	What It Means
Sound	Something you hear with your ears.
Vibrate	To shake back and forth very fast.
Vibration	The fast shaking that makes sound.
Investigate	To try something out and watch what happens, like a scientist.
Pattern	Something that happens the same way again and again.

SECTION 8

Show What You Know!

1

Maya holds a comb and runs her finger across the teeth. She hears a buzzing noise. What is happening to the comb's teeth when she hears the sound?

2

Leo wants to investigate how a tissue box with a rubber band stretched over the hole makes sound. What should he do first to plan his investigation?

3

Sophia taps a metal spoon on the edge of a glass of water. She sees tiny ripples in the water and hears a ringing sound. What does this investigation show?

4

Kai places small grains of rice on top of a drum. He hits the drum and the rice grains jump up. Then he stops hitting the drum and the rice stops jumping. What can Kai conclude from this investigation?

SECTION 9

What's Next?

🔮 WHAT'S NEXT?