[Roly1650]

Not even the church have ever held the idea of a flat earth as official doctrine, mainly, I suspect, because a spherical earth didn't challenge the idea of mankind's central position in god's creation.

The Egyptian you're thinking of is Eratosthenes, who was ~16% off in his calculations.

It may not have been the official line, but it was certainly used at the grass roots to keep the peasants in line.

As for Eratosthenes, it would appear that impossible to beleve, but we are both right, from Wikipedia:

"An early report on the circumference of the Earth was given by Aristotle at 400,000 stadia.[1] The first scientific estimation of the radius of the Earth was given by Eratosthenes about 240 BC. Estimates of the accuracy of Eratosthenes’s measurement range from within 2% to within 15%."

And:
"He is best known for being the first person to calculate the circumference of the Earth, which he did by applying a measuring system using stadia, a standard unit of measure during that time period. His calculation was remarkably accurate. He was also the first to calculate the tilt of the Earth's axis (again with remarkable accuracy). Additionally, he may have accurately calculated the distance from the Earth to the Sun and invented the leap day.[4] He created the first map of the world incorporating parallels and meridians, based on the available geographical knowledge of the era."

In the mathematical genius category I'd say.

 

[Roly1650]

Actually I disagree.

If you actually try to find information about "the frequency range of human hearing" you will find that subject mentioned in a lot of books... and most of them seem to agree that everybody else seems to agree that "the commonly accepted range of human hearing is 20 Hz to 20 kHz". At one point I tried to research exactly where that number came from, and I reached a point where most books were simply quoting other books, or saying that "it was commonly accepted". Now, while it may in fact be true, I am always leery of things that "everybody knows", but nobody seems to want to quote the original research to substantiate. (So, while most people in the middle ages "knew" the world was flat because their priest said so, a lot of people today just seem to accept that "it's commonly known that the limit of human hearing is 20 Hz to 20 kHz", which to me seems a lot like the same blind acceptance of presumed authority. While I found plenty of books and references that states the limits of human hearing as "commonly accepted", I entirely failed to find mention of an actual test, performed by an author of one of those books, to confirm this "well known" information.) Considering that, in the last twenty or thirty years, a lot of "commonly known facts" have turned out NOT to be true, I'm not willing to simply accept this one at face value because it's been repeated a lot - for a very long time.

Note that I have run across several references where individuals state that "they have found this to be true" - which is clearly anecdotal; I've also found one reference that "human hearing extends down to 12 Hz under laboratory conditions"; and one or two others claiming to have "detected response to frequencies well above 20 kHz in humans under some circumstances"; and at least one other that claimed to have shown that test subjects heard differences in samples that were band-limited to 20 kHz when compared to those that weren't (that study seemed to show that limiting the bandwidth to 20 kHz caused a shift in the perceived location of some instruments in the sound stage).

In short, I don't think that "fact" rises anywhere near the level of certainty necessary to justify using it to claim that further research is pointless or unnecessary.

I think there's a fair chance you didn't read my post......

 

[OddE]

.
The Egyptian you're thinking of is Eratosthenes, who was ~16% off in his calculations.

-That depends on what definition of the length of a Stadion you prefer; he may well have been off by slightly under one percent.

 

[limpidglitch]

It may not have been the official line, but it was certainly used at the grass roots to keep the peasants in line.

As for Eratosthenes, it would appear that impossible to beleve, but we are both right, from Wikipedia:

"An early report on the circumference of the Earth was given by Aristotle at 400,000 stadia.[1] The first scientific estimation of the radius of the Earth was given by Eratosthenes about 240 BC. Estimates of the accuracy of Eratosthenes’s measurement range from within 2% to within 15%."

And:
"He is best known for being the first person to calculate the circumference of the Earth, which he did by applying a measuring system using stadia, a standard unit of measure during that time period. His calculation was remarkably accurate. He was also the first to calculate the tilt of the Earth's axis (again with remarkable accuracy). Additionally, he may have accurately calculated the distance from the Earth to the Sun and invented the leap day.[4] He created the first map of the world incorporating parallels and meridians, based on the available geographical knowledge of the era."

In the mathematical genius category I'd say.

 
16% seems much more probable to me, considering the method he used to measure the distance between Alexandria and Aswan(?).
 
And 16% isn't bad, considering that Columbus was ~25% off in 1492

 

[Roly1650]

16% seems much more probable to me, considering method he used to measure the distance between Alexandria and Aswan(?).

And 16% isn't bad, considering that Columbus was ~25% off in 1492

Yea, but 2% is much more impressive.

Columbus wasn't off 25%, this fecking great lump of land jumped in his way, otherwise he'd have hit India no problem.

 

[limpidglitch]

Yea, but 2% is much more impressive.

Columbus wasn't off 25%, this fecking great lump of land jumped in his way, otherwise he'd have hit India no problem.

 
If that great lump of land hadn't been there, he's likely to have starved to death.
 
Currently reading up a bit on al-Biruni. Now there's a guy who knew how to measure the world, 800 years before Humboldt.

 

[Roly1650]

If that great lump of land hadn't been there, he's likely to have starved to death.

Currently reading up a bit on al-Biruni. Now there's a guy who knew how to measure the world, 800 years before Humboldt.

Thanks for the link, very interesting. It's amazing how much the sum store of human knowledge was advancing in the rest of the known world while Europe was submerged in the Dark Ages.

 

[limpidglitch]

I found another article by the same author that goes into more detail on his geodesy. Really impressive stuff.

 

[Roly1650]

I found another article by the same author that goes into more detail on his geodesy. Really impressive stuff.

Thanks again, both articles will be read and digested.

 

[old tech]

   
Just to be clear - I'm not actually challenging anything one way or the other - because I haven't run a properly controlled test (and, again, even if I personally couldn't hear a difference, that wouldn't prove that nobody can). My main point is that "the established science" may simply not be right. Five hundred years ago, the established science they taught in school was that the Earth was flat, and tomatoes were poisonous; now we know better. When I went to high school, they taught in science class that all matter was made up of protons, neutrons, and electrons - which were the smallest indivisible "pieces" of matter; and that model was good enough to bring us nuclear power plants and the fusion bomb; but now we find that notion quaint, and there's an active debate about whether matter is "really" vibrating 11-dimensional energy strings, or a collection of smaller particles called quarks, or something not quite either one. And, the last time I looked, we still don't know exactly how the human brain works (and "hearing" occurs in both the ears and the brain).
 
Incidentally, for an interesting experiment, go buy yourself one of those new souped up half watt LASER pointers that operates at 720 nm or 840 nm; that's the "invisible infrared" color used by a lot of remote controls; and a LASER puts out a very clean single frequency. Shine the dot somewhere and you will probably find that the "invisible" dot is in fact clearly visible; I can see it quite clearly as a pale pink - and so can most people. So I guess the "science" about IR light being "invisible" is wrong too. (Actually, in order to be visible to most of us, it has to be so bright that it is somewhat dangerous to look at for more than a few seconds, but my point stands - the "commonly accepted fact" is in fact wrong. And, in fact, a TV that was actually able to display long-wave IR, and so make the bright sun in the picture of the desert actually feel warm on your face, would - at least to me - have much better fidelity than the one I have now.)
 
I don't know for sure whether the difference between 16/44k and 24/192k is audible - everything else being exactly equal, but I'm absolutely positive that I don't necessarily trust the "truth" as "discovered" by scientists back when most audiophiles were certain that a Dynaco Stereo 70 and Koss pro4AA's "sounded audibly perfect" because both "covered the entire audible spectrum". And, with many modern DACs with selectable filters, there are differences that many people find audible which seem to coincide with different sample rates and different filter responses producing audible differences. Perhaps there's something there; or perhaps what we're hearing is simply that a given DAC handles 16/44k differently than it handles 24/192k - because it uses a different oversampling multiple; and perhaps the endless discussions in one or two pro sound forum about how certain sample rate converters sound better or worse with certain types of music is all superstition as well (audiophiles have nothing on pros for superstitious beliefs). However, I'm not quite prepared to say that "audio science is at its end because there's lots of equipment available today that's audibly perfect, so there's nothing to improve."
 
Personally, since the science shows clearly that high-res files are in fact superior in quality (frequency response and dynamic range) - whether that superiority is audible or not - then to me that's enough justification for continuing to improve things.... and for studying whether those technical improvements lead to some sort of audible improvements. I can also say that, personally, I'm willing to pay a bit extra for a technical improvement even if that improvement doesn't yield anything that's currently important - or even noticeable. (If it turns out that nobody can hear the difference, that still won't prove that the extra information that's there won't be useful to some new "3D decoder" someone comes out with next year, or some other gadget neither of us can guess at, and so won't prove it "totally useless".) I also simply see the latest "fad" for high-res remasters as being generally a good thing - because at the very least it encourages people to listen to music carefully enough that they are actually hearing it. (I'd rather see people spending money on high-res players that don't sound different than on cheesy 128k MP3 players which they imagine "don't sound much different" - because the latter is a slippery slope I'd rather avoid approaching.)
 
Now, if you want to start a new thread entitled "What is the best and most practical sample rate and bit depth to use for distributing consumer music?" then I might well be inclined to agree with you on a lot more things.
 

I agree with you on the point that there is no harm in obtaining a higher than 16/44 res recording, especially given that storage space is cheap. (*with one qualification that very high sample rates eg 192khz may introduce distortions into the playback system).  However doing so, in the belief that the higher res file on its own will result in an improvement in playback fidelity is misguided.
 
The examples you provided of how claims that the Dynaco Stereo 70 and Koss pro4AA's are prefect show how the science can be wrong is not valid.  That may have been the claim by some audiophiles, but there was no real science backing up that claim.  There are many issues of non-linearity in frequency response which mean that no transducers or room acoustics (in the average home) can be perfect. That is quite different to the hundred years of experiments which demonstrate that the range of human hearing falls between 20 to 20,000hz.  The latter is not merely an audiophile claim (indeed many audiophiles don't accept this, hence the demand for hi res), but accepted by all the science disciplines - try convincing an audioligist that tests patients in their clinics day in day out that this is not the case.
 
The example of infra red which can be seen, doesn't prove anything either.  The frequency range of human vision is also well understood and that range includes frequencies which some people call infra red.  In reality, it is not infra red in the true meaning of the word but the upper limit of light frequency which we can percieve.  A bit like saying that 17khz audio is "ultra sonic".  For example, you can see the "infra red" light, even if it is faint, on some remote controls but on most you cannot.  The ones you can see are within the human range of vision while those you can't see are just outside it.
 
I agree that there can be differences in DACs behaving differently at different sample or bit rates.  But there is no technical reason why any competently implemented DAC should have this issue, even if some do have this issue.  Using your speaker analogy, there is no competently designed DAC that is non-linear so its reproduction of the frequency response in the human hearing range going to be much more perfect (broadly defined) than what you would get out of a speaker. In any event, non of this has anything to do with the issue at hand of human hearing limits, these are issues of hardware or software design and implementation.
 
Lastly, the main issue I have with hi res audio is that it is distracting manufacturers and consumers on what are the real issues of concern with high fidelity and where R&D effort ans marketing should be focused, that is the design of speakers, room acoustics and most importantly, the mastering of the sound material in the first place.

 

[dprimary]

   
Actually I disagree.
 
If you actually try to find information about "the frequency range of human hearing" you will find that subject mentioned in a lot of books... and most of them seem to agree that everybody else seems to agree that "the commonly accepted range of human hearing is 20 Hz to 20 kHz". At one point I tried to research exactly where that number came from, and I reached a point where most books were simply quoting other books, or saying that "it was commonly accepted". Now, while it may in fact be true, I am always leery of things that "everybody knows", but nobody seems to want to quote the original research to substantiate. (So, while most people in the middle ages "knew" the world was flat because their priest said so, a lot of people today just seem to accept that "it's commonly known that the limit of human hearing is 20 Hz to 20 kHz", which to me seems a lot like the same blind acceptance of presumed authority. While I found plenty of books and references that states the limits of human hearing as "commonly accepted", I entirely failed to find mention of an actual test, performed by an author of one of those books, to confirm this "well known" information.) Considering that, in the last twenty or thirty years, a lot of "commonly known facts" have turned out NOT to be true, I'm not willing to simply accept this one at face value because it's been repeated a lot - for a very long time.
 
Note that I have run across several references where individuals state that "they have found this to be true" - which is clearly anecdotal; I've also found one reference that "human hearing extends down to 12 Hz under laboratory conditions"; and one or two others claiming to have "detected response to frequencies well above 20 kHz in humans under some circumstances"; and at least one other that claimed to have shown that test subjects heard differences in samples that were band-limited to 20 kHz when compared to those that weren't (that study seemed to show that limiting the bandwidth to 20 kHz caused a shift in the perceived location of some instruments in the sound stage).
 
In short, I don't think that "fact" rises anywhere near the level of certainty necessary to justify using it to claim that further research is pointless or unnecessary.
 
 
 
 
 

How far back did you go?
 
Francis Galton was researching it in back in 1883 and had whistles made that went to 84k page 26 and page 252 he writes about them. Not much in details of what he found.
http://www.mugu.com/galton/books/human-faculty/text/galton-1883-human-faculty-v4.pdf
 
The Evolution of Human Hearing
Bruce Masterton1, Henry Heffner1 and Richard Ravizza1 J. Acoust. Soc. Am. 45, 966 (1969)
 
Measured the upper limit to be 18KHz with threshold of audibility being 80dBSPL vs 0dBSPL for 4kHz where we are most sensitive.
 
There was tons of research done in the 50's you could spend months going through references back over 100 years.

 

[dprimary]

   
I agree there.... there are many different filter types and options - and they only tested one of them (and proving that a single filter is audible doesn't prove that others are). I would have also liked it if they had included a few more types of test equipment (since they basically used one DAC and one pair of speakers). I've always found electrostatic headphones to be the best thing for picking out minute audible differences, so that would have been my choice there.
 
As for the accusations that the authors "had an agenda".... personally I'm inclined to say that, if they did, I saw no evidence to that effect. (To put it bluntly, while the test produced a "statistically significant" result, it would hardly serve to convince people that there's some sort of significant and obvious difference worth paying for. In fact, it tended more to suggest that the difference was there, but was rather minor and difficult to hear.)
 
I have to admit that I'm at a bit of a disadvantage here in that classical music isn't what I normally listen to, so I personally would not be the most likely person to notice whether the sounds of specific instruments, or the sound of the ambiance in a real concert hall, were or were not "rendered accurately".

I don't think I implied they had an agenda. The test did prove it well enough to warrant more study. I agree the differences for this and many things in audio are so minor most people would never pay for it. When you need complete concentration in a NC 20 room to hear the difference your market is very small.
 
The piece of music they used is very well recorded. We could place the position of each member clearly. Every recording engineer in the room was impressed. We only listened to twice since we are trying to troubleshoot an issue with the monitors

 

[RRod]

  I don't think I implied they had an agenda. The test did prove it well enough to warrant more study. I agree the differences for this and many things in audio are so minor most people would never pay for it. When you need complete concentration in a NC 20 room to hear the difference your market is very small.
 
The piece of music they used is very well recorded. We could place the position of each member clearly. Every recording engineer in the room was impressed. We only listened to twice since we are trying to troubleshoot an issue with the monitors

 
What piece is it?

 

[KeithEmo]

  I agree with you on the point that there is no harm in obtaining a higher than 16/44 res recording, especially given that storage space is cheap. (*with one qualification that very high sample rates eg 192khz may introduce distortions into the playback system).  However doing so, in the belief that the higher res file on its own will result in an improvement in playback fidelity is misguided.
 
The examples you provided of how claims that the Dynaco Stereo 70 and Koss pro4AA's are prefect show how the science can be wrong is not valid.  That may have been the claim by some audiophiles, but there was no real science backing up that claim.  There are many issues of non-linearity in frequency response which mean that no transducers or room acoustics (in the average home) can be perfect. That is quite different to the hundred years of experiments which demonstrate that the range of human hearing falls between 20 to 20,000hz.  The latter is not merely an audiophile claim (indeed many audiophiles don't accept this, hence the demand for hi res), but accepted by all the science disciplines - try convincing an audioligist that tests patients in their clinics day in day out that this is not the case.
 
The example of infra red which can be seen, doesn't prove anything either.  The frequency range of human vision is also well understood and that range includes frequencies which some people call infra red.  In reality, it is not infra red in the true meaning of the word but the upper limit of light frequency which we can percieve.  A bit like saying that 17khz audio is "ultra sonic".  For example, you can see the "infra red" light, even if it is faint, on some remote controls but on most you cannot.  The ones you can see are within the human range of vision while those you can't see are just outside it.
 
I agree that there can be differences in DACs behaving differently at different sample or bit rates.  But there is no technical reason why any competently implemented DAC should have this issue, even if some do have this issue.  Using your speaker analogy, there is no competently designed DAC that is non-linear so its reproduction of the frequency response in the human hearing range going to be much more perfect (broadly defined) than what you would get out of a speaker. In any event, non of this has anything to do with the issue at hand of human hearing limits, these are issues of hardware or software design and implementation.
 
Lastly, the main issue I have with hi res audio is that it is distracting manufacturers and consumers on what are the real issues of concern with high fidelity and where R&D effort ans marketing should be focused, that is the design of speakers, room acoustics and most importantly, the mastering of the sound material in the first place.

 
Actually I think the example of a Stereo 70 is absolutely pertinent. First, if you look around, you will see many claims that "there is no audible difference between tube and solid state electronics as long as the frequency response and THD remain below audible limits" - and the Stereo 70 would fit the criteria stated in those claims for "a tube amp that shouldn't sound audibly different from a solid state amp of equivalent power as long as you don't overload either one". However, my real point there was that, when most of the tests most people reference were actually performed, those were both "the latest equipment"... and, back when the Stereo 70 was current, a lot of people did in fact claim that "there was no point in doing any further development because it was plenty good to satisfy the abilities of human hearing" - and most of us no longer consider that claim to be true. In fact, that same claim has been made for tube amplifiers, vinyl recordings, cassette recordings, open reel recordings, and CDs... but opinions of whether it is true or not for each of them have changed over time. Perhaps, twenty years from now, people will look back and say "they were right - and CDs really are good enough to sound perfect within the limits of human hearing", but I'm not convinced about that - at least not yet. (Perhaps, instead, everyone will own a $20 pair of headphones - or some sort of other technology for listening to music entirely - through which the difference between CDs and high-res files is obvious. I read one interesting, but somewhat vague, paper claiming that humans had been confirmed to be able to hear well above 20 kHz - using bone conduction rather than "through the air conduction"- which bypasses the mechanisms of the middle ear - which they claimed was "what limited human hearing to 20 kHz".)
 
As for DACs, I agree that no well-designed DAC should have high enough noise or distortion, or a frequency response far enough off-flat, that it should be audible. However, their transient responses can vary considerably depending on how their filter is designed, and I don't recall anyone doing any definitive tests about whether that is audible or not. And transient response is generally shown with an oscilloscope trace picture - so there is no single commonly accepted "spec" to compare. (There seems to be general agreement that time errors become audible at some point - but nobody seems to agree on where that line would be.)
 
I definitely agree with what I consider your most important point - which (to me) is that the single biggest issue with most modern recordings is the mastering itself. Very few modern CDs are produced well enough that they sound anywhere near as good as the format is capable of. I also agree that, for most people, speakers and the acoustics of the room they're located in also probably make a much bigger difference.
 
I do, however, disagree with what I guess would be the logistics of a few of your other statements.
 
Assuming that "the music industry" was monolithic, I agree that I would rather see money spent on better production values and mastering than on higher resolution. However, the production industry is not monolithic. The companies selling DACs are not the same companies who are producing albums. And the choice of whether to deliver a given master at 16/44k or 24/192k is merely a matter of picking a different setting (or, at worst, buying one new piece of equipment). In short, I don't see producing content at a higher resolution as "diverting funds from anywhere else". I also believe that the current obsession with high-res content, even if it turned out to be technically meaningless, is still "a step in the right direction", because at the very least it encourages people to pay attention to the technical aspects of the music they're listening to. (Given the choice, I'd rather have consumers wondering whether 24/192k sounds better rather than wondering if 128k MP3 files are "good enough for them". So I see the trend of simply paying attention to the production quality of the music as a good thing.) In other words, perhaps, if people really are paying attention to what the music they're buying sounds like, and are a little more demanding when they are asked to pay extra for a "high-res version", that will in fact encourage the industry to use better production values all around. (But I do agree that it won't help if people start assuming or imagining that the new version is better because it's high-res alone - to the point of ignoring whether it actually sounds good or not.)
 
I'm also a firm believer in "trickle down technology".... the idea that, if manufacturers of players, and amplifiers, and speakers, work to make their top end products capable of playing flat to 40 kHz, just maybe the end result will be that even their low end products get a tiny bit better - as better technology becomes "the norm". (Maybe, if the DAC vendors get more orders for 24/192k DACs, they'll drop ones that don't even work well at 16/44k from the bottom of their product line, which will mean that you'll end up with a better DAC in the next $20 player you buy - because this year's "cheapest DAC you can buy" will be a little bit better than last year's.)

 

[KeithEmo]

 
How far back did you go?
 
Francis Galton was researching it in back in 1883 and had whistles made that went to 84k page 26 and page 252 he writes about them. Not much in details of what he found.
http://www.mugu.com/galton/books/human-faculty/text/galton-1883-human-faculty-v4.pdf
 
The Evolution of Human Hearing
Bruce Masterton1, Henry Heffner1 and Richard Ravizza1 J. Acoust. Soc. Am. 45, 966 (1969)
 
Measured the upper limit to be 18KHz with threshold of audibility being 80dBSPL vs 0dBSPL for 4kHz where we are most sensitive.
 
There was tons of research done in the 50's you could spend months going through references back over 100 years.

 
Actually, I was looking on the Internet for some specific references, and most of what I got when I searched on "limits of human hearing" and such things was references to relatively recent textbooks which, when I actually tracked them down, said things like "it is widely accepted" or "it is commonly believed" or simply referenced some other book in the footnotes... 
 
And I have two basic problems with this situation.....
 
First, it's usually bad when people start accepting things "because they're generally known" or "because everybody knows".... If I was someone new to the audiophile world, I could read on this forum how "everybody knows human hearing doesn't extend above 20 kHz", but I could read on a different thread that "everybody knows vinyl sounds better than digital", and in another venue entirely about all sorts of folk remedies that "everybody knows work".... and I'm pretty sure there's a thread pretty nearby where "everybody knows that high-def files sound better". So, without specific references to test results, how should I know which "everybody knows" is in fact correct? (The Internet seems to be a bad influence here - encouraging many people to simply repeat what they hear rather than to even take the effort to track down quotes and sources... and, in this case, the most references you will find repeat the 20 Hz to 20 kHz number. People actually seem to forget that many of the entries on Wikipedia may well have been written by people who don't actually know any more than they do; and repetition has come to be associated with "truth".)
 
Second, and related, is that we tend to generalize a bit too much... and things that are "generally true" may still not be "always true" (and many people seem to not make that distinction). If we want to make a claim that "most humans can't hear above 20 kHz", then we can safely test a few hundred people, and report those results as being "generally applicable to humans" - however they cannot be claimed to apply to all humans. I don't expect to make it to 100 years old - yet there is a long list of folks who made it to 115 - so you cannot set "the top limit on human life expectancy at 100". (If you want to test whether anyone can hear past 20 kHz, you'd be better off offering a $1000 prize to anyone who can demonstrate that they can hear 22 kHz - by which you avoid having to test everyone on Earth yourself by providing a clear incentive for subjects to self-select. And it would be easy enough to offer a prize to anyone who can hear the difference between a high-res file and the 16/44k equivalent; we could leave it to someone claiming the opposite to produce two otherwise identical files, offer the test subject his or her choice of equipment to listen to them with, and see whether the subject can distinguish them or not. And, if one single person comes forward who can reliably tell the difference, then we have to stop saying that "nobody can".)
 
(My main problem with the "direction" of this thread is that I believe that most of us are really more concerned with whether we, or perhaps most people, can hear a difference.... yet the question hasn't been phrased that way. I'm reminded of one of the early science experiments looking for "exotic" subatomic particles - involving a massive tank of cleaning solvent and a sensor looking for "the telltale flash" the particular particle would produce. I believe that, in the first several months, after a lot of observations, they detected ONE.... which still proved that the particle did in fact exist. I simply haven't seen this level of thoroughness expended looking for any single human who can hear above 20 kHz. If the real object here is to prove that high-res files don't make sense because most people are unable to actually hear the difference, then we can do so with a much smaller sample... and a lot less work.) 
 
Incidentally, thanks for that Galton link - it is most interesting....