Our friend, The Giant Squidstravaganza, sent us a cool gift from the beach: some awesome seashells! Have you ever put a shell over your ear and listened carefully? You might have heard a sound that reminds you of the ocean. But guess what? That sound isn’t from the ocean at all!
The sound you hear inside the shell actually comes from the noises all around us. All sounds are made by vibrations. When something vibrates, it moves back and forth really fast, so fast that we usually can’t see it. For example, when you ring a bell, the metal vibrates quickly. This vibration shakes the air around it, and when the vibrating air reaches our ears, it sends a message to our brains, and we hear a sound.
Even when it seems quiet, there are always sounds around us. It could be cars passing by, the wind blowing through trees, or even the beating of your heart. These sounds send vibrations to our ears, but we often don’t notice them because we’re busy with other things. Right now, your brain is focusing on my voice, even though there are other noises around you.
When you put a shell over your ear, it changes how the vibrations from background noises reach your ears. The shell makes some of these vibrations bounce around and get louder. When we focus on these vibrations, our brains hear a roaring sound that reminds us of the ocean!
You can try this at home without a seashell! Ask a grownup for a plastic cup or a small plastic bowl. Find a place with some background noise, but not too loud. Put the cup over your ear and listen. Do you hear a soft roaring sound? The cup makes the vibrations from the background noise bounce around, just like a seashell does.
Shells of different sizes and shapes will make the vibrations bounce in different ways, so you might hear different kinds of roars. Different background noises can also change the sound you hear inside the shell. Try using different kinds and sizes of cups, or listen in different places in your house or outside. Does the sound change?
Squeaks and I are going to try this experiment in different places around the Fort. But first, we’re writing a thank you note to The Giant Squidstravaganza for the beautiful shell! Did you try this experiment? What did you learn? Ask a grownup to help you leave a comment below, or send us an email at [email protected]. We’ll see you next time here at the Fort!
Sound Detective: Go on a sound hunt around your home or backyard. Close your eyes and listen carefully. Can you identify at least five different sounds? Write them down or draw pictures of what you think is making each sound. Discuss with a friend or family member how these sounds might be different if you listened to them through a seashell or a cup.
Make Your Own Ocean Sound: Gather a few different objects like a plastic cup, a paper towel roll, and a small bowl. Take turns placing each object over your ear and listen to the sounds around you. Which object makes the sound the loudest? Which one makes it the softest? Try to explain why you think each object changes the sound differently.
Vibration Exploration: With the help of an adult, fill a shallow pan with a little bit of water. Gently tap the side of the pan and watch what happens to the water. Can you see the vibrations? Try tapping harder or softer and observe the changes. Discuss how these vibrations are similar to the ones that create sound in the air.
