Loud and Quiet: The Size of a Vibration

Science · Waves, Light & Sound · ages 8-9

Name ______________________ Date ____________

What word describes how loud or quiet a sound is?
- Pitch
- Volume
- Echo
When something vibrates with bigger movements, is the sound louder or quieter?
- Louder
- Quieter
- It stays the same
The size of a vibration changes how loud a sound is.
Circle one: True False
You pluck a rubber band gently and it makes a quiet twang. How can you make it louder?
- Pluck it harder so it swings further
- Pluck it more slowly
- Touch it to stop it moving
Ben taps a drum gently, then hits it hard. What happens to the drum skin's vibrations?
- They get smaller
- They stop moving
- They get bigger
Look at the bars. Which one shows the bigger vibration?
- Soft tap
- Hard hit
- They are the same
You hear a guitar string played softly, then the same string played hard. What changed about the string's vibration to make the second sound louder?
- It swung through a bigger distance back and forth
- The string got longer
- The string stopped moving between notes
Leo says: 'A quiet sound means the object is vibrating faster.' What is wrong with what Leo said?
- Leo is completely right
- Quiet sounds have no vibrations at all
- Quiet sounds come from smaller vibrations, not faster ones

Answer key

For grown-ups. Fold this page away before handing over the rest.

Volume · Volume is the word for how loud or quiet a sound is.
Louder · Bigger vibrations carry more energy, so they make a louder sound.
True · Bigger vibrations make louder sounds, and smaller vibrations make quieter sounds.
Pluck it harder so it swings further · Plucking harder makes the rubber band swing through a bigger movement, which makes a louder sound.
They get bigger · Hitting harder pushes the drum skin further, so the vibrations grow bigger.
Hard hit · The taller bar for the hard hit shows a bigger vibration, which makes a louder sound.
It swung through a bigger distance back and forth · Playing harder makes the string swing through a bigger distance, and that bigger vibration makes the louder sound.
Quiet sounds come from smaller vibrations, not faster ones · Volume depends on how big the vibrations are, not how fast they happen. Small vibrations make quiet sounds.