Neat writeup! From the title, I had my fingers crossed that they integrated ADS-B flight tracking data to show a map of where the sound of airplanes in the air is currently observable.

If anyone wants to go down that rabbit hole really far, I'm imagining general profiles of the sound each airplane makes, considering altitude, different sound propagation by frequency depending on distance the sound travels, and geography. Might as well throw air properties in too, to minimize the overall error. The user could provide their location and see the estimated arrival time and frequency of the sound from the airplanes in the sky.