This is a video from Destin of Youtube channel Smarter Every Day detailing how cicadas are able to make such an ungodly racket, filming their noisemakers at 110,000FPS. Basically, male cicadas have special organs on the sides of their thorax called tymbals. When their muscles are flexed, the tymbals’ ribs buckle quickly in sequence, producing a click for every rib’s collapse (similar to pop-tube toys — Popoids to 80’s children). The resulting vibrations from both sides meet in the middle of its center resonant cavity and are released as sounds waves, which can reach up to 100dB. And all this to get the attention of a potential mate! It’s the bug equivalent of screaming “HEY BABE, OVER HERE!” at the top of your lungs, which, at least in my experience, does not produce the results you hope it would.

Keep going for the video, but it should start around the really good stuff.