Great story and beautifully done! I first lived with ambient monitoring of computers in 1971. I was a mainframe operator (which means you changed tapes) at a research lab and someone had hooked an DA converter to the accumulator and plugged in a speaker. It was crazy but after a couple of weeks, you KNEW what the machine was up to from the variation in sounds and you used it to do your job. I think it’s probably underrated as a technique.