The sensing device is a MEMS microphone that outputs a pulse density modulated (PDM) signal. There are chips available to directly interface such a microphone to a USB port, but [Mahesh] found ...

[Breaking Taps] has an investigation of a MEMS chip. MEMS is short for Micro Electromechanical Systems, which operate in a decidedly mechanical way. You can see the video, which has some gorgeous ...