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lionelag
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20-20khz. (JA? KR?)

This is prompted in part by the near-war going on in another forum about the Furutech demag.

Audio writers, especially those of the objective data type, talk about 20hz-20khz being the limits of human hearing, excepting the occasional young person (when I was 16, I could clearly hear out to 22khz without more than about a 3db drop).

It happens I'm reading Helmholtz's classic 19th century work "On the Sensations of Tone," and his experiments show human hearing out to at least *40khz* with no substantial db drop. (Helmholtz's translator Ellis reports being able to hear 40,000hz from a tone generator at a distance of 100 feet-- this is on p. 18 of the Dover edition) Helmholtz's terminology is exactly the same (he of course refers to cycles per second rather than Hertz, but considers A to be between 435 and 440cps), and the experiments look pretty much the same as the ones I did in 11th grade physics lab 20 years ago. Except for the results.

So here's the question-- is there a problem with Helmholtz's saws and bows (or academic honesty?) that I'm missing, or has human hearing gotten substantially worse since the Industrial Revolution?

Kal Rubinson
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Re: 20-20khz. (JA? KR?)

I have not read Helmholtz in decades but I suspect that his technology for testing the range above 20KHz was flawed and included intermodulation products. Heck, it is difficult even today.

Kal

Jan Vigne
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Re: 20-20khz. (JA? KR?)


Quote:
It happens I'm reading Helmholtz's classic 19th century work "On the Sensations of Tone"

If no one else will ask the question ...

You just haaaaappen to be reading Helmholtz?! What happened, the Ambien prescription run out? You had one selection to fulfill for Publisher's Clearing House?

I believe in knowing the history of the hobby, but, ya'know, aren't there, like, you know, Cliff Notes to this thing?

Elk
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Re: 20-20khz. (JA? KR?)

I read On the Sensations of Tone in high school, purely out of curiosity. It's a great primer on the physical characteristics of sound.

It is fascinating how Helmoltz developed his understanding of sound - concepts we take as a given today.

Hardly dull stuff.

Jan Vigne
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Re: 20-20khz. (JA? KR?)

No doubt but for a page turner it's hard to top Newton's Philosophiae Naturalis Principia Mathematica from 1687.

However, "the apple fell to the ground" pretty much sums it up.

lionelag
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Re: 20-20khz. (JA? KR?)


Quote:

Quote:
It happens I'm reading Helmholtz's classic 19th century work "On the Sensations of Tone"

If no one else will ask the question ...

You just haaaaappen to be reading Helmholtz?! What happened, the Ambien prescription run out? You had one selection to fulfill for Publisher's Clearing House?

Far more mundane reason. My primary job involves reading lots and lots of emails relating to pharmacology for discovery in a lawsuit. (I have a small law practice on the side, but 9-5, I'm generally reading email-- hey, it's paying work. If anyone reading this in the Philadelphia area is in a position to hire a bright geeky lawyer with about half a dozen years in civil litigation, contact me off list) I suspect that even a pharmacologist or physician would go mad. About six months back, my employers started cracking down on internet usage and newspapers, (since it looked to outside observers like everyone was goofing off, all the time) while acknowledging that no, no human in their right mind could read (and annotate) this stuff 8 hours straight.

Answer: PDF files on a flash drive. It happens that most of the easy-to-get books are out of copyright ones, and Helmholtz came up while I was browsing through Project Gutenberg. It's actually pretty interesting reading, though it is slow going (and requires lots of physics I haven't thought about since high school).

lionelag
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Re: 20-20khz. (JA? KR?)


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I have not read Helmholtz in decades but I suspect that his technology for testing the range above 20KHz was flawed and included intermodulation products. Heck, it is difficult even today.

Kal

Oh, I'm sure that in 1877, when the book was written, the technology for measuring wasn't much more than "lift your hand if you hear the tone, please." He just seems so sure of the measurements (citing another paper, in fact, for the same numbers) and the translator, in his note, mentions hearing the tones without any "upper partial beats," which seems to be the way Helmholtz and Ellis refer to harmonic intermodulation.

Elk
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Re: 20-20khz. (JA? KR?)


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However, "the apple fell to the ground" pretty much sums it up.


Hardly.

While you may have little curiosity to satisfy, there is no reason to condescendingly dismiss others' interest in the world - including the history of science.

You previously extolled the virtues of understanding:


Quote:
Would it be presumptuous of me to say you will learn only by reading what you don't understand? You have to make the attempt to gain knowledge before you can move forward to a better understanding.

(odd emphasis of "understand" as in your original statement) Cite

Elk
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Re: 20-20khz. (JA? KR?)


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My primary job involves reading lots and lots of emails relating to pharmacology for discovery in a lawsuit.

Been there. MDL 1203 (Diet Drugs, USDC for the Eastern District of Penn) is still not finished - over ten years of fun and frolic. I cannot wait to close my files.

You are probably aware of the 10/03/96 email of Wyeth's Kay Anderson to Dr. Patricia Acri, Wyeth's director of product labeling:

"Am I off the hook or can I look forward to in my waning years signing checks for fat people who are a little afraid of some silly lung problem?"

PPH. A silly lung problem.

Can you say puni's?

lionelag
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Re: 20-20khz. (JA? KR?)


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Been there. MDL 1203 (Diet Drugs, USDC for the Eastern District of Penn) is still not finished - over ten years of fun and frolic. I cannot wait to close my files.

I'm not on that one (though I know one of the partners in the plaintiff's class action firm that got what, about $2b in fees from it?), but yeah, same sort of stuff. Lower profile drug with far fewer deaths, same extensive paper trail, mondo MDL case, several zillion pages of emails scanned in or exported to PDF. Mindless tedium. If it weren't for the e-books and the fact that I can listen to music 6-8 hours a day (on an ipod hooked to a total bithead, sennheiser noise-cancelling 'phones), I would have gone mad quite a while ago. Helmholtz is a blessed relief.

Jan Vigne
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Re: 20-20khz. (JA? KR?)

Geez, Elk, laugh. What is this? Everybody's got hinky over everything on every thread. Ease up for goodness sake.

"I just happened to be reading Helmholtz." Right, I just happened to be painting the Mona Lisa or building the Empire State Building.

Nobody just happens to be reading Helmholtz. You happen to be reading the back of a cereal box or the graffitti in the bathroon stall. But not Helmholtz. Criminny!

Get over it. OK?

Elk
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Re: 20-20khz. (JA? KR?)

Poor Jan . . . able to dish it out but can't take it.

Elk
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Re: 20-20khz. (JA? KR?)


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I'm not on that one (though I know one of the partners in the plaintiff's class action firm that got what, about $2b in fees from it?), but yeah, same sort of stuff.


There are 27 firms that make up the PMC in MDL 1203. I don't know the total fees off hand but they are not that high.

Right now the Special Master is in the process of calculating a partial refund of PMC fees as the formula originally approved generated more fees than anticipated. Thus I am in the process of getting some more money out of already settled cases.

Good luck keeping your mind agile during your doc review - one of the glamorous parts of law.

Jan Vigne
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Re: 20-20khz. (JA? KR?)

Ohhh, good lord, Elk let's no go there again.

Lamont Sanford
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Re: 20-20khz. (JA? KR?)

Well, I'll have to get out my test CD and see if I can still hear 20khz on my monsters. What dB should I crank the volume up to? What?

Posted in memory of DUP. RIP. QED.

SAS Audio
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Re: 20-20khz. (JA? KR?)


Quote:
This is prompted in part by the near-war going on in another forum about the Furutech demag.

Audio writers, especially those of the objective data type, talk about 20hz-20khz being the limits of human hearing, excepting the occasional young person (when I was 16, I could clearly hear out to 22khz without more than about a 3db drop).

It happens I'm reading Helmholtz's classic 19th century work "On the Sensations of Tone," and his experiments show human hearing out to at least *40khz* with no substantial db drop. (Helmholtz's translator Ellis reports being able to hear 40,000hz from a tone generator at a distance of 100 feet-- this is on p. 18 of the Dover edition) Helmholtz's terminology is exactly the same (he of course refers to cycles per second rather than Hertz, but considers A to be between 435 and 440cps), and the experiments look pretty much the same as the ones I did in 11th grade physics lab 20 years ago. Except for the results.

So here's the question-- is there a problem with Helmholtz's saws and bows (or academic honesty?) that I'm missing, or has human hearing gotten substantially worse since the Industrial Revolution?

Hi Lionel,

Here is an article of a panel discussion, including a hypothesis that might help.
http://www.stereophile.com/news/10860/


Quote:
Chaired by Malcolm O.J. Hawksford of the University of Essex, the panel of experts discussed several obstacles to achieving higher levels of resolution in audio recording and playback. Mike Story, of dCS, Ltd., made a strong case for promoting ultra-wide audio bandwidth as a hi-rez standard
judicata
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Re: 20-20khz. (JA? KR?)


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If it weren't for the e-books and the fact that I can listen to music 6-8 hours a day (on an ipod hooked to a total bithead, sennheiser noise-cancelling 'phones), I would have gone mad quite a while ago. Helmholtz is a blessed relief.

Junior litigation associate at a large NYC law firm here (and happen to be involved in some pharma cases as well - can't say more). I think a setup like that for music is absolutely essential to avoid insanity to get through doc review. Heck, even for legal research, motion drafting, and depo preps. But especially for tedious doc review. I've preferred open headphones, though, so I can hear my phone ring.

I actually have a box of documents to sift through today. Yes, such a glamorous profession.

Buddha
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Re: 20-20khz. (JA? KR?)


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I have not read Helmholtz in decades but I suspect that his technology for testing the range above 20KHz was flawed and included intermodulation products. Heck, it is difficult even today.

Kal

I would initialy put my feet in with Kal's reply.

One thing about this subject, though, that intrigues me is the issue of harmonics and their 'implied' frequencies.

Please, spare me if this is a dumb series of questions...

We know that a fundamental tone does more than present as the fundamental tone. We get harmonics or overtones at integral multiples of the fundamental. Hence, good treble response can help flesh out the beauty of a musical note played in the lower midrange.

However, I have read about 'undertones,' as well; harmonics that occur below a fundamental frequency.

So, even if we can only hear to 18K, perhaps a system that could reproduce to 40K would produce undertones that we would use to extrapolate to the original higher frequency fundamental and we would sort of 'fill in' the presence of the higher frequency information, which may enhance our perception of the music we are listening to.

So, maybe there is some high frequency 'trickle down' (voodoo audionomics?) that takes place that we don't often talk about.

Then, at risk of being even more obtuse, I often wonder how what we hear at home approximates what was played at all...

If sounding a note generates harmonics, then what we do when we try to play back that note is have the mic capture all the original sounds, then, as precisely as possible, relay that data to our speakers, which sound those notes again...but wouldn't the speaker making those sounds then create a whole new batch of harmonics of all the notes it is playing?

Don't we end up listening to harmonics that never existed in the original listening environment?

There's so much going on, it boggles me with regard to just how close we can get in terms of sound quality, yet how startlingly far away we remain.

Kal Rubinson
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Re: 20-20khz. (JA? KR?)


Quote:

One thing about this subject, though, that intrigues me is the issue of harmonics and their 'implied' frequencies.

Please, spare me if this is a dumb series of questions...

We know that a fundamental tone does more than present as the fundamental tone. We get harmonics or overtones at integral multiples of the fundamental. Hence, good treble response can help flesh out the beauty of a musical note played in the lower midrange.

However, I have read about 'undertones,' as well; harmonics that occur below a fundamental frequency.

This is also a description of intermodulation distortion. However, if that interaction occurs in performance/recording, it should be conveyed within the normal audible bandwidth of recordings.


Quote:
If sounding a note generates harmonics, then what we do when we try to play back that note is have the mic capture all the original sounds, then, as precisely as possible, relay that data to our speakers, which sound those notes again...but wouldn't the speaker making those sounds then create a whole new batch of harmonics of all the notes it is playing?

Yes, particularly if that interaction was influenced by the listening room acoustics, rather than just the performance acoustics.


Quote:
Don't we end up listening to harmonics that never existed in the original listening environment?

Kal

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