Researchers from Ben-Gurion University (Israel) have developed a method of reconstructing a conversation by observing an ordinary honey - the technology is called "Lamphone". As it turned out, when a sound wave hits the surface of the bulb, vibrations are created, causing microscopic fluctuations of light.
A light bulb hanging from the ceiling acts both as a diaphragm, on the surface of which a cascade of sound waves propagates, and as a transducer that transforms the pressure of sound vibrations into subtle changes in light. Thus, the special services received at their disposal one more means of wiretapping.
According to the researchers, all the Lamphone needs is a laptop, a telescope, a microphone and a remote electro-optical sensor that converts light into an electrical signal.
To test their device, the researchers set up a test site on a footbridge 25 meters from the office on the third floor in a commercial building. Their goal was a simple 12-watt LED light bulb, and by observing it, they were able to recreate the speech and music sounding inside the office.
To do this, they used three telescopes with different lens diameters - 10, 20 and 35 centimeters and installed an electro-optical sensor on each telescope lens for each session. Through an analog-to-digital converter, the researchers obtained information about the vibrations in the light bulb, and then processed it using a special algorithm. As a result, they got a recording of Trump's speech, which was able to recognize the Speech-To-Text API from Google and a recording of "Let It Be" by the Beatles, which was able to recognize Shazam.