Reminds me of a neat video I saw once on the inner workings of a sheet metal stamping factory (for car parts). They used a directional microphone array pointed

Reminds me of a neat video I saw once on the inner workings of a sheet metal stamping factory (for car parts). They used a directional microphone array pointed at the inspected machine and compared audio waves and overlayed “hot spots” on a display to see how the machine was working and where it was malfunctioning.