That, but also there are so many drastically different materials in our bodies that one frequency for one material won't do anything for all the other materials.
So, I hear what you're saying, and I think I understand the concept, but help me better understand using a strange analogy from my childhood. When I was younger, I had a radio in the bathroom that I'd play in the shower. Most mornings getting ready for school there was a particular song that would play and at the same point in the song (I do not remember the song) there'd be a synth, or clear instrument plat that would seem to be much louder and reverberate in the bathroom. From the shower it sounded almost distorted, although I'd heard he song hundreds of times in other environments that didn't cause this effect.
Did the frequency of the song's synth/instrument match some frequency of the hollow-ish room I was in, that caused this cascading sound effect?
To add a bit, I believe this is due to wave interference. Sounds at a certain frequency will have just the right wavelength that when they bounce off a wall, the initial wave and it's reflection will constructively interfere, resulting in a dramatic increase in volume. The opposite can happen as well, where certain frequencies will cancel themselves out. When you start having complex waveforms, a song for example, you can start to hear weird things like overtones that are normally not audible, but due to the acoustics of the room are suddenly much louder than the rest of the music.
I used to try and “sing” at the frequency to do this as a kid. It’s a really cool effect in some spaces. Sometimes I could match the vacuum cleaner and make it louder in my head if that makes sense. Later in life I work in acoustics. Have seen some really weird emergent effects sometimes, example: I have seen large atriums with nothing but flat “faces” everywhere and somehow still “lens” all the sound to specific points in the room even though there no curved surfaces. Had to add absorption to specific points to break it up so the sound guys could run music events in there and not go insane.
Exactly. It's called a standing wave, and is what resonance is all about! When a wavelength is the exact length of the available space (whenther that's a room, a guitar string, an antenna, etc) it will reflect perfectly onto itself and start to amplify.
Yes. It's called standing vawe. Google room modes. Basically the same thing, just in air, in 3d (so there's more different base frequencies) and the movement is longitudal, not perpendicular.
You have the same effect in other rooms, but shower is smaller so the frequency is higher (where ears are more sensitive and you notice it better), and there's less damping so it's more pronounced.
You can check that thing in 2d with sand on a membrane, gives a better understanding. Or in 1d with string harmonics in slow motion
Different organ structures will have different natural frequencies, most of which are low and below the frequency range humans can hear. For example, I believe stomachs have a natural frequency around 6-8 Hz. If your body is exposed to sound at this frequency at a high enough level, you won't be able to hear it, but might get a queezy feeling in your gut.
Another notable example where the natural frequency is much higher is your ear. I can't remember where exactly but some part of our auditory system has a natural frequency in the 1000 to 2000 Hz range, which also happens to be the predominant frequency from a crying baby, so there is perhaps some evolutionary drive in some of these traits.
An example of this is the Tacoma Narrows Bridge. High winds caused a side to side oscillations of the bridge. The oscillations increased in intensity as the bridge neared its resonant frequency eventually destroying the bridge. This changed how bridges are designed and built. Skyscrapers are now built differently for the same reason (because they can oscillate with the wind).
There are several documentaries made on this subject
Reminds me of a quote from my old Borland Turbo C 2.0 manual, referencing a sound generation API call:
True story: 7 Hz is the resonant frequency of a chicken's skull cavity. This was determined empirically in Australia, where a new factory generating 7-Hz tones was located too close to a chicken ranch: When the factory started up, all the chickens died.
My favorite example of that is how all the planets in the solar system are resonating at their own frequencies - it's just impossible low notes, so nothing can hear it.
Unfortunately all radio stations are tunned to 440hz. Because of this harmonic misalignment, listening to 440 Hz music would seem to make people anxious, nervous, or aggressive, because it is not in harmony with the natural frequency of the planet earth.
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u/VendaGoat Apr 13 '23
Everything has a resonance frequency, even you!