The Science of Sound

Good Vibrations

What sounds do you hear every day? Your own voice? Your dog barking? In one day you will hear hundreds of sounds. You make some of them yourself by talking and singing, clapping your hands, or by zipping up and down the sidewalk on skates. Other sounds just happen naturally, like the sound of rain falling on a roof, or a bird singing.

What do all these sounds have in common? They are all caused by movement. It's easy to see your hands move when you clap them. But what do you think moves when you sing or talk? It's your vocal cords. They vibrate every time you say something.

Scientist's Corner
Here's an experiment to try. See if you can feel your voice making sound!

What To Do
Try touching your throat while you talk. Can you feel the vibrations? Now try signing as low as your voice will go. Can you feel the slower vibration? Now try signing as high as you can. What changed?

What You Discovered
You could easily feel your throat vibrating when you sang really low. The vibrations were harder to feel when you sang high.

Why
Low sounds are caused by slow vibrations, which you can easily feel. High sounds are produced by faster, usually smaller, movements that are harder to feel.

Now Try This
You can do an experiment to see how stringed instruments, like guitars and violins, make sounds. To find out how click here.

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