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Hearing Damage over 20khz?

I own speakers that produce in excess of 40khz, yet the human ear can only perceive 20khz.

If something is uncomfortably loud we can hear, we know to turn it down but what if the frequency is out of our audible range?

Is it possible hearing is being damaged by something we can't hear?

I have read reports of people having ears ring after using speakers that can go beyond 20k, but I don't know if it's due to the sounds produced below 20k or above or both.

It would be horrible to learn I was damaging my children's ears or mine without knowing it.
vintagegroove
eldartford
4,262 posts
 
Measurements of hearing (eg:20KHz) are based on sine waves. But lower frequency waveforms that are not sinusoidal can have wavefronts with slopes well in excess of the fundamental frequency. I believe that the ear detects wavefront slope. You may not hear a 30 KHz sine wave and yet limitation of slew rate to that corresponding to 20 KHz sine wave is audible.

I have experienced exactly this effect, except that, at my age, both frequencies are lower.
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shadorne
7,467 posts
 
There is no evidence that the ear detects wavefront slope. The ear is like a digital device - hairs in the cochlea move and trigger nerve bundles. The on and off of the nerve bundles allows us to determine frequencies or tones. The combination of frequencies and the way they decay determines the timbre or sound.
eldartford
4,262 posts
 
Shadorne... And there are woofer hairs, midrange hairs, and tweeter hairs. However, the ON/OFF mechanization can represent waveform as well as frequency.

What is your explanation of ability to sense the existance or absence of frequencies higher than measured sine wave sensitivity?
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shadorne
7,467 posts
 
What is your explanation of ability to sense the existance or absence of frequencies higher than measured sine wave sensitivity?

Huh? Not sure I understand you. I don't think there is evidence that we hear higher frequencies.

A square wave is made up of all odd harmonics...you hear the odd harmonics up to the point where you can no longer hear them (around 15 KHz for most people)...so you do not hear the "slope" of the square wave but within your audible hearing range you hear the harmonic content that makes up the square wave.
eldartford
4,262 posts
 
Shadorne... I am very familiar with Fourier analysis. (I used it a lot in my role as a test design engineer).

Evidently you have not experienced the phenomina which I described. The ongoing interest in supertweeters is further evidence that frequencies above the measured hearing range do matter.
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