Is there a cheap way for me to get light from sound? If not, is there an expensive way?
Maybe you can do the opposite of the sound from light method used by the CIA to listen inside office buildings by using a laser reflected off the vibrating window of the office. The vibrations of course being from the people talking inside which affects the laser beam which is then converted back to sound for big brother. Simple as that!
investigate piezoelectric crystals.
Connect a microphone to a LED.
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