An oscilloscope is a machine that can be used to visualize sound waves. When we increase the volume of a sound, the amplitude of the wave is increased. The frequency of a wave is related to its pitch. If the pitch is high, then the frequency of the wave is high. This means that the wave will looked squashed on an oscilloscope trace.
In this activity, students will create a chart that shows how an oscilloscope trace relates to what a sound wave sounds like. Students can modify the wave shape using the crop and resize functions. You can make this activity more difficult by quantifying the changes in the waves. For example if the wave is twice as loud, then the wave will be twice as high.
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Student Instructions
Create a storyboard that demonstrates how an oscilloscope trace relates to what the sound wave sounds like.
Engage students by using simple objects to visualize sound waves, making abstract concepts more concrete and memorable for grades 2–8 learners.
Collecting easily available items ensures every student can participate. Rubber bands can mimic strings, while cups and rulers serve as supports and amplifiers.
Show how vibrations create sound by striking or plucking the rubber bands stretched across a cup or between two supports. Highlight the visible movement and the sound produced.
Encourage students to adjust the rubber band tension or length and observe how pitch and volume change. This hands-on manipulation helps them connect physical changes to sound properties.
Have students sketch simple waveforms on paper to represent loud, soft, high, and low sounds. This step builds a bridge between auditory experience and visual representation of sound waves.
An oscilloscope displays sound waves as visual traces. Louder sounds appear as taller waves (higher amplitude), while higher-pitched sounds have waves that are more closely packed together (higher frequency).
Amplitude on an oscilloscope trace shows the volume of a sound. When the amplitude increases, the sound gets louder, and the trace becomes taller on the screen.
To show pitch changes on an oscilloscope, increase the frequency of the wave—this makes the waves appear more squashed together. Ask students to compare traces with the same amplitude but different frequencies for a clear example.
Try activities where students draw or modify wave traces using crop and resize tools, matching different pitches and volumes, or create a chart comparing how changes in amplitude and frequency affect the visual trace and the sound.
Higher-pitched sounds have a greater frequency, meaning more wave cycles occur in the same time, so the trace looks more compressed or 'squashed' on the oscilloscope screen.