Wait. I forgot to put in the crystals.
Some reason I always thought that the crystal was struck to generate an electric signal not added electricity to vibrate. TIL!
That is done too. It works in both directions. What you’re describing is a microphone. A quartz crystal is vibrated and it generates an electric signal. If you play that electric signal back into the crystal it reproduces the sound, aka a speaker. The design of the two change obviously to improve quality for their purpose, but if you have a headset or something with a 3.5mm jack with separate mic/speaker inputs, try plugging them in the opposite way. Your mic will start playing sound and your speaker will produce input when it hears things.
I’d be interested in a little more detail about how it counts the vibrations, excludes outside motion, etc.
Neat, very concise and informative
