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CHAPTER 5: Sounds - Pg. 127

CHAPTER 5 Sounds The ADK board on its own is not capable of generating or detecting sounds. Luckily there is one component that can help with both of these tasks: the piezo buzzer. What is the definition of sound? Sound, in general is a set of waves of pressure that can be transmitted through solids, liquids, and gases. A piezo buzzer transmits sound through the air by oscillating at different frequencies. The different frequencies of those waves make up the different sounds you are able to hear. A human being is capable of hearing frequencies in the range of 20Hz up to 20,000Hz. The unit for frequencies is Hz (Hertz). It defines the number of cycles per second. So the more sound waves the human ear detects per second, the higher the perceived sound is. If you have ever stood close to a big audio speaker box you may have seen the membrane of the speaker vibrating. That's