Have you ever noticed that it’s harder to hear someone when they’re far away? Their voice gets quieter until you can’t hear them at all! But guess what? There’s a fun way to talk to your friend from a distance without yelling, and you can make it yourself!
Before we start building, let’s talk about how sound works. All noises, like music, birds singing, or people talking, are made by vibrations. Vibrations happen when something moves back and forth. Even though these movements are usually too small and fast to see, you can often feel them!
Try this: put your hand on your throat and say your name. Feel that buzzing? That’s a vibration, the start of the sound of your voice! It’s caused by two little things in your throat called vocal cords. You can also see vibrations when you strum a guitar. The string moves really fast, creating sound!
When something vibrates, it makes the air around it move. Air is made of tiny particles, and these particles carry the vibrations through the air so sound can travel. For example, when a guitar string vibrates, it moves the air particles around it, which then bump into other particles, carrying the sound to your ears.
Now, let’s make a string phone to see how sound can travel through something other than air. Here’s what you’ll need:
Follow these steps:
Can your friend hear you? Pretty cool, right?
When you talk into the cup, your voice makes the air particles inside the cup vibrate. These vibrations move the bottom of the cup and travel along the string. The string carries the vibrations to the other cup, where they make the air particles inside vibrate, reaching your friend’s ear!
Try this experiment: Stand closer to your friend so the string is loose. Can you hear them? Not really! The string needs to be tight to vibrate well and carry sound. When it’s loose, it doesn’t work as well.
Keep experimenting with your string phone. How long can you make the string before the sound goes away? Let us know how it goes by emailing us at [email protected] or leaving a comment below.
Thanks to Google Making Science for helping us make this episode, and thank you for watching. See you next time!
Sound Detective: Go on a sound hunt around your home or school. Listen carefully and try to identify different sounds. Can you find out what is making each sound? Write down or draw pictures of the things you hear. Think about how the vibrations might be traveling to your ears. Share your findings with a friend or family member!
Vibration Exploration: Gather some household items like a rubber band, a spoon, and a piece of paper. Try to make each item vibrate and produce sound. For example, stretch a rubber band between your fingers and pluck it. What do you notice? How does the sound change if you stretch the rubber band tighter or looser? Discuss your observations with a classmate or family member.
String Phone Challenge: Experiment with different types of string or yarn for your string phone. Try using a thicker or thinner string, or a different material like yarn or fishing line. Does the sound travel better or worse? Why do you think that is? Record your results and share them with your class or family.
