Spectrum analysis of white noise

White noise

High School



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A noise is a sound made up of a multitude of sounds of random frequencies, volumes and durations. White noise is a particular noise whose spectral components have equivalent energy per cycle (in hertz). This results in a "flat" spectrum when plotting the frequency spectrum. The study of white noise is interesting because it allows us to make an analogy with white light. The very simple protocol shows the student the random characteristic of the frequencies that make up white noise and trains them to ask questions about the concept of noise, and the analogy between sound and light.

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Sample protocol for the student
1. What is white noise and why is it called that?
2. In the sound library choose white noise
3. Play the sound, what do you hear? How would you characterize this sound? To the ear, is this sound made up of one or more frequencies? How much do you think?
4. What Instrument could you use to study the frequencies that make up white noise?
5. With this instrument, make several measurements of the frequency spectrum of white noise.
6. What do you see? Are the frequencies the same from one graph to another?
7. Add a few more bars, is your intuition confirmed?
8. How would you characterize white noise?
9. Can you explain the term white noise by making an analogy with another physical phenomenon?
10. Organize your observations in your experiment notebook by adding text and photos and share it as a PDF

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