OT: It's not actually a "noise camera". It's a speed camera with some directional microphones that triggers if there is too much noise, probably with some filte

OT: It's not actually a "noise camera". It's a speed camera with some directional microphones that triggers if there is too much noise, probably with some filtering to try to avoid triggering on noise that isn't loud car noise. There are actually acoustic cameras that are much more like a "camera" in that you get a 2D map of the sound reaching the device. This can be overlaid on an image from a light camera and you get an image where you can see where all the sounds are coming from. Some of them can make acoustic movies, where each frame is a light camera image overlaid with the sound map, usually coloring the optical image based on the sound with color indicating frequency and brightness indicating loudness. With these you can do neat things like make a sharp sound and see the echo bounce around a room, or look at something making a variety of sounds and see which sounds are coming from where. They often include software that is kind of an audio image version of Photoshop. You can use that software's equivalent of the eye dropper tool to point anywhere in the image and here the sound coming from that point. E.g., if you had an acoustic movie of the strings of piano and the pianist was playing a 10 note chord you could pick an individual string and play back the sound of just that string. Here's a video where science YouTuber Steve Mould was loaned some to play around with, showing some of the cool things you can do with them [1]. [1] https://www.youtube.com/watch?v=QtMTvsi-4Hw https://www.youtube.com/watch?v=QtMTvsi-4Hw