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 ...

Knowles of the U.S. in 2013 was the biggest supplier of packaged MEMS microphones ready for assembly on printed circuit boards, according to IHS Technology. Germany’s Infineon, meanwhile, was the ...