The Doppler effect is a well-documented phenomenon in physics which causes a change in the frequency of a wave as the source moves closer to the observer. It’s the science behind satellites and speed cameras alike. And, in the hands of one computer science student, it can make a little magic happen on your computer.
As long as you have a working microphone and speakers in your laptop (and you’re running Chrome), you can scroll up and down the page, play a Theremin, or just watch the computer track you waving your hands around.
The demo is a proof of concept, but given the number of devices packing microphones and speakers, this technique could be used to add gesture control into almost anything. [Daniel Rapp/Github]