[jtaillon]

Surprisingly, this isn't really true (as far as noise is concerned). Noise pollution travels far, and if you're using sensitive equipment, you can easily pick up the noise of planes flying nearby at 30,000 ft.

[paulmd]

This is in fact how airplanes were detected before radar was invented. Not a joke.

https://rarehistoricalphotos.com/aircraft-detection-radar-19...

https://en.wikipedia.org/wiki/Acoustic_location

[DonHopkins]

Now you've made me want to dress up as an Airplane Detector for Halloween!