Fun facts: Helmholtz Resonators [1] are used all over industry and in aerospace to do just this. For instance the shroud around a high bypass turbo fan will hav

Fun facts: Helmholtz Resonators [1] are used all over industry and in aerospace to do just this. For instance the shroud around a high bypass turbo fan will have a honeycomb sandwich layer with precise holes in the middle of each cell to create an array of resonators tuned to cancel out specific frequencies. My favorite application similar but different from what you’re describing from antiquity is the acoustical effect of certain Mayan and Aztec pyramids. Here’s a video[2] [1] https://en.wikipedia.org/wiki/Helmholtz_resonance https://en.wikipedia.org/wiki/Helmholtz_resonance [2] https://youtube.com/watch?v=wsMGCF_pS-M https://youtube.com/watch?v=wsMGCF_pS-M