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0 pointsenriquto4y ago0 comments

The quoted sentence seems false to me. Most physical objects do not have naturally harmonic vibration spectra. The vibration modes are not integer multiples ofthe fundamental (except for a vibrating string). Only the finely tuned western instruments do. So this is a somewhat backwards argument.

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jacquesm4y ago

> Most physical objects do not have naturally harmonic vibration spectra.

What is your basis for saying this?

A large number of physical objects, solids as well as hollow can be approximated as systems of springs, surfaces and tensile elements, which all have some frequency response. It isn't rare at all for a physical system to have a very sharp resonant peak in its frequency response, to the point that you'll often find mechanisms to dampen that response so the structure will survive certain inputs.

HelloNurse4y ago

Many objects don't have audible vibration modes (infrasonic, ultrasonic, so damped that sounds are too brief and too quiet) but it doesn't mean that they don't vibrate.

enriqutoOP4y ago

what you are describing is a graph. The laplacian spectrum of a graph is arbitrary.

PEJOE4y ago

Every rigid object has a fundamental frequency, regardless of whether you put it on a graph.

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kortex4y ago

You have the causality backwards though. It isn't saying most objects emit quantized overtones. But if you hear quantized overtones, there's a very good chance they are from the same source.

It's not just strings, either. Drum heads have varying degrees of quantized modes.

OscarCunningham4y ago

The code itself also contradicts that sentence. Notice that the first roughness graph doesn't have any local minima at rational numbers. It's only when the overtones are added to the notes (at integer multiples of the fundamental frequency) that the minima appear.

So the code thinks that human ears don't detect integer multiples specifically, they just detect sounds whose overtones line up with each other.

sideshowb4y ago

Good point, but our ears definitely do perceive the 2 to 1 ratio. Maybe that particular phenomenon is better analysed through the usual pschoacoustic approach of "at what point do we stop perceiving one sound and start perceiving two "?

IggleSniggle4y ago

I don't think so. If a sound persists long enough to hear its continuation, then its partials are generally going to be harmonic. Non-resonant frequencies will have a tendency to dissipate very quickly, unless they are explicitly designed to warble between resonances (like a gong or similar).

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