The Sound of Silence
How do noise-canceling headphones work?
Students will
- Given the frequency of a pure tone, calculate the period of its sound wave
- Sketch the graph of a chord composed of two tones and estimate its period and frequency
- Describe any apparent relationship between a chord’s period and its perceived pleasantness
- Sketch the graph of a pure tone’s noise-canceling counterpart and construct multiple functions to describe it
- Develop general procedures for generating a noise-cancelling wave from a given pure tone
- Examine some difficulties in describing noise-canceling waves for chords
- Explain how noise-canceling headphones work and why they are not always completely effective
Before you begin
Students should be familiar with the general form of sinusoids (i.e. f(x) = Asin(Bx – C) + D or f(x) = Acos(Bx – C) + D) and how changes in the parameters affect their graphs.Common Core Standards
Content Standards
Mathematical Practices
Downloads
Additional Materials
- Graphing Technology
Shoutouts
Kyle Jones, Smithsonian; image courtesy of Patrik Theander (https://www.flickr.com/
photos/fabolous/8627113727/)
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