A stronger vibration can make a larger pressure change in the air. The size of that change is called amplitude. Change the height of the coloured wave and compare it with the dashed reference. The number of repeats stays the same, so the model pitch does not change. Doubling amplitude gives four times the model intensity; that is not the same as saying it sounds four times as loud.
Light, sound and electricity · Discover & try
How does wave size relate to sound strength?
Reading level 1 of 5 · EarlyChange
Word help
amplitude
The size of a repeated change around its middle value.
intensity
Energy flow per unit area in the physical comparison.
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Pressure amplitude and relative intensity at fixed frequency; no real sound level or hearing test.
What to look for
- Amplitude changes height
- Frequency stays fixed
- Relative intensity follows amplitude squared
Explain what you noticed
Pressure amplitude rises from 2 to 6 units in the same medium. By what factor does this model intensity change?
Keep this idea: Wave amplitude and perceived loudness are related but different quantities.
Follow the sources
- NIH Curriculum Supplement — Hearing, Communication, and Understanding
- NIH / NIDCD — How Is Sound Measured?
- OpenStax, Rice University — Sound Intensity and Sound Level
Source material checked 2026-10-29. Explanations and activities by Nepedia. Source links do not imply endorsement.
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