Advanced PlacementHigh School / Physics

Decoding DTMF Tones

Students will use a wireless sound sensor and the fast Fourier Transform (FFT) display of the data collection software to analyze the tones produced when dialing a phone. They will uncover the pattern of these dual frequency tones showing the first frequency gives the row of the key on the numeric keypad and the second frequency gives the column. From this information they can determine what key is pressed without seeing it.

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Featured Equipment

Wireless Sound Sensor

Wireless Sound Sensor that measures sound waves and sound level.

Many lab activities can be conducted with our Wireless, PASPORT, or even ScienceWorkshop sensors and equipment. For assistance with substituting compatible instruments, contact PASCO Technical Support. We're here to help.

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