Sound and vibrations

For grown-ups: this lesson in words

Years 4 to 6 · Science

Sound and vibrations: I can explain how sounds are made and travel, and how pitch, volume and distance change what we hear.

1. Here is a drum. When the stick hits it, the drum skin vibrates: it moves back and forth very quickly.

   The drum is the source of the sound. The source is the thing that makes the sound.

   The vibrations pass into the air. The curved lines show them spreading out through the air.

   They travel through the air to the ear. When the vibrations reach the ear, we hear the sound.

   Picture: A stick hits a drum on the left. Curved lines spread out through the air from the drum to an ear on the right. Labels: source, vibration and ear.

2. Every sound is made by something vibrating. Let's sort these by how we play them.

   Hit a drum or a bell, and the drum skin or the bell's metal vibrates.

   Pluck a guitar, and its strings vibrate.

   Blow into a trumpet, and the air inside it vibrates.

   Picture: Sorting into 3 groups: Hit it, Pluck it, Blow into it. Hit it: Drum: the skin vibrates (drum), Bell: the metal vibrates (bell). Pluck it: Guitar: the strings vibrate (guitar). Blow into it: Trumpet: air inside vibrates (trumpet).

3. Your turn: Zara plucks a string on her guitar, and it makes a sound. What is the string doing while it makes the sound?

   Choose one:

   • Staying completely still
   • Vibrating: moving back and forth very quickly
   • Soaking up sound from the air

   Answer

   The answer: Vibrating: moving back and forth very quickly

   The string is vibrating. Its vibrations make the sound.

Words to know

vibrate:

To move back and forth very quickly, again and again.

source:

The thing that makes a sound, like a drum or a bell.

pitch:

How high or low a sound is.

volume:

How loud or quiet a sound is.

fainter:

Quieter and harder to hear.