What Is Sound? for Kids

What is sound? Have you ever heard the saying, if a tree falls in the forest and no one is around to hear it fall, does it make a sound? What do you think? Is sound something you can only hear if you see something happening, like a tree falling? Or is sound something totally different? Today, we are going to talk all about sound, what it is, and how it works. Let's try a little sound-related activity. Take a moment and close your eyes. Focus on what you hear. Maybe you hear a car driving down the street, or a cabinet closing in the kitchen. Maybe you can just hear this video. Either way, there are sounds all around you, and we are going to talk about how sound is made. Sound is made from vibrations. What are vibrations, you ask? Well, vibrations are a series of small, fast movements that move back and forth, or from side to side, like a guitar string, or your voice. Guess what? You can actually feel the vibrations of your voice. Just rest your hand on the front of your throat and hum your favorite song. Do you feel the vibrations of your vocal cords? Pretty cool, huh? Here is an interesting fact. When an object vibrates, it causes movement in the surrounding air particles. These particles bump into other particles that are close to them, which makes them vibrate too. And this process continues until the particles run out of energy, kind of like dominoes. This movement is called sound waves. Sound waves are what help vibrations travel. If you are close enough to an object's vibrations, the sound waves that are created will reach your ear. The air particles of the sound waves then vibrate in your ear, which causes your eardrum to also vibrate. This allows you to hear the sound. Now that we know how sound is made and how it travels, let's talk for a minute about pitch and volume. Pitch is the highness or lowness of a sound. Pitch changes when the sound waves go faster or slower. When the vibrations are faster, you hear a higher note. When they are slower, the note is lower. Hey, that rhymes! Volume measures the loudness or quietness of a sound. This is called its intensity, which is a fancy way of saying power. The higher the intensity of a sound, the louder our ears hear it and the higher its volume. Volume changes when sound waves are bigger or smaller. Here is an interesting experiment to try. Place a piece of paper with a handful of uncooked rice on top of a stereo speaker. Turn the speaker on, quiet music, and watch how the rice jumps. Slowly turn the volume up until the music is really loud. What happens to the rice as the volume increases? That is right, it jumps higher. Isn't science cool? Now that we have learned all about the science of sound, let's see what you remember. Fill in the blank. Blank waves help vibrations travel. Sound. True or false. Pitch is the loudness or quietness of a sound. False. Pitch is the highness or lowness of a sound. Fill in the blank. Blank is the loudness or quietness of a sound. Volume. Nice work, sound sorcerers! So now that we know about the science of sound, let's go back to that initial question. Does a falling tree in the middle of the forest make a sound, even if there is no one around? Yup, it does. Vibrations and sound waves are created, no matter what. Now that is something fascinating you can share with your family and friends. Hope you had fun learning with us. Visit us at learnbright.org for thousands of free resources and turnkey solutions for teachers and homeschoolers.