Watch the source move, then follow one coloured air particle. Crowded regions and spread-out regions travel along the row, but the marked particle only moves back and forth. That is the difference between a travelling sound disturbance and the motion of the material carrying it. Sound needs a material through which to travel.
Light, sound and electricity · Discover & try
How does a vibration travel as sound?
Reading level 2 of 5 · DevelopingChange
Word help
vibration
Repeated movement around a resting position.
compression
A region where the model particles are closer together.
Watch · Try · Explain
See how it works
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Slowed, one-dimensional air-particle model; particle spacing and motion are exaggerated and no sound plays.
What to look for
- Crowded regions move along the row
- The marked particle stays local
- The source moves back and forth
Explain what you noticed
A doorbell is 10 metres from a listener. What does an air particle beside the bell do as its sound passes?
Keep this idea: A sound pattern travels while air particles oscillate locally.
Follow the sources
Source material checked 2026-10-28. Explanations and activities by Nepedia. Source links do not imply endorsement.
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