Sonic Sensor

An interesting effect produced accidentally in the lab. A sound level monitor is connected to an oscilloscope from its DC output, and it is placed between two speakers playing a 1kHz tone. When you move your hand in towards the sound level monitor it creates reflection and slightly changes the monitored levels. In this way, it detects even minute movements with what seems to be pretty good precision.
What I didn't show in the video is that it also detects lateral movement. The little peaks on the scope move right or left with the hand moving right or left near the sound level meter.
This is part of a project to connect a series of sensors to a Raspberry Pi for one of our researchers.