Keep pitch fixed
The trace always shows four cycles in the same time window, representing a fixed 440 Hz frequency.
Sound Loudness Studio
Change sound-wave amplitude while frequency stays fixed at 440 Hz.
Grades 3–5 · Physics
Your goal
Set amplitude to 20 percent, keep 440 Hz and step the vibration.
Reduced motion is on. The controls still update the scene.
Amplitude 0 percent. Frequency stays 440 Hz. Relative wave energy is 0 percent of full amplitude. Larger amplitude usually sounds louder. This wave picture is silent.
percent
This silent studio compares sound waves without playing audio. Each step advances one sixteenth of a cycle so the vibration can be examined slowly. At fixed frequency, medium and listening position, wave energy scales with amplitude squared. Perceived loudness also depends on ears and surroundings, so the energy percentage is not a loudness percentage. The speaker displacement and wave height are enlarged illustrations.
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Learn with Sound Loudness Studio
Sound Loudness Studio helps elementary students separate wave height from pitch using a silent sound-wave picture. Change the amplitude control and compare the trace with the speaker illustration, then step through a vibration one frame at a time. The number of cycles in the displayed time window stays fixed because the frequency remains 440 hertz. Read the relative wave energy bar to investigate why doubling amplitude changes energy by a larger factor. Goals build confidence with amplitude while making clear that perceived loudness is not a simple energy percentage.
What to look for
Inspect a cycle
Step the vibration to see another phase without automatic motion or audio.
Compare energy
Doubling amplitude gives four times the relative wave energy under the same conditions.
For teachers and curious learners
Distinguish wave amplitude and relative energy from frequency and pitch. Ask students to predict what will happen, change one setting, and explain what they observe. Learn gives a starting point. Practice and Challenge offer new goals with the same scene.
This silent visual model fixes frequency at 440 Hz and advances one sixteenth of a cycle per step. Relative wave energy scales with amplitude squared at a fixed medium and position; it is not a perceived-loudness percentage.