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Topic: Next page in the hi-rez media scam: A Meta-Analysis of High Resolution Audio Perceptual Evaluation (Read 99803 times) previous topic - next topic
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Re: A Meta-Analysis of High Resolution Audio Perceptual Evaluation

Reply #75 –
Quote from: pelmazo on
Quote from: Arnold B. Krueger on
The oft-quoted source for  measurements showing that the ear has > 120 dB dynamic range is often " Louis D. Fielder. May 1981. Dynamic Range Requirement for Subjective Noise Free Reproduction of Music"  That argument and others are based on the idea that the human ear can hear a pure tone at a frequency where it is most sensitive with an amplitude of about - 6 dB. The threshold of pain is usually given as 120 dB SPL or so, so the ear's dynamic range must be ca.  126 dB and we need reproduction systems capable of doing this.
I reviewed this article, and I think you remember it wrongly. Fielder actually refers to just noticeable noise levels, rather than just noticeable tone levels. So he actually does compare apples to apples.

In order to reach 118 dB of required dynamic range, he had to take the most extreme percussive classical music, close-mike it, and assume the most acute listener in detecting a noise floor increase. You'd have to have the very quietest part, where noise floor differences might be heard by a few people, before the loud part, because after the loud part nobody would detect such noise floor differences anymore.


in a *second*, more extensive study, published in 1985, Fielder used a mic at 'favored listening locations' in an audience, and still measured peaks ranging from 90-129dB (classical topped out at 118dB, it was a rock show that generated 129)

please see:

http://www.aes.org/tmpFiles/elib/20160630/10206.pdf

which summarizes results of his and others' work,

Re: A Meta-Analysis of High Resolution Audio Perceptual Evaluation

Reply #76 –
The paper is open access, but can non-members see the comments?
Loudspeaker manufacturer

Re: A Meta-Analysis of High Resolution Audio Perceptual Evaluation

Reply #77 –
Quote from: krabapple on
in a *second*, more extensive study, published in 1985, Fielder used a mic at 'favored listening locations' in an audience, and still measured peaks ranging from 90-129dB (classical topped out at 118dB, it was a rock show that generated 129)
There certainly are people at rock concerts whose favored listening location leads to such levels, but I very much doubt they care much about just noticeable noise levels. ;-)

His approach apparently consists of finding the extremes in both directions, no matter whether they apply to the same case or not. The difference is the required dynamic range for him.

Well it certainly makes life simpler if your sound system has this dynamic range throughout, because it relieves the sound engineer of having to tweak the levels to use the available dynamic range wisely. You could basically calibrate your mic-pre with the mic's sensitivity, and regardless of what you record, it'll always be ok. With contemporary converter technology, I'd posit that we are approximately there, if his numbers are to be taken as the gospel.

It has very little to do with what you need in a carrier for distribution to the consumer, however. Whoever uses his numbers to justify HRA as a distribution format changes the context significantly.

Re: A Meta-Analysis of High Resolution Audio Perceptual Evaluation

Reply #79 –
Quote from: pelmazo on
Quote from: Arnold B. Krueger on
The oft-quoted source for  measurements showing that the ear has > 120 dB dynamic range is often " Louis D. Fielder. May 1981. Dynamic Range Requirement for Subjective Noise Free Reproduction of Music"  That argument and others are based on the idea that the human ear can hear a pure tone at a frequency where it is most sensitive with an amplitude of about - 6 dB. The threshold of pain is usually given as 120 dB SPL or so, so the ear's dynamic range must be ca.  126 dB and we need reproduction systems capable of doing this.
I reviewed this article, and I think you remember it wrongly. Fielder actually refers to just noticeable noise levels, rather than just noticeable tone levels. So he actually does compare apples to apples.

Yes, I remembered the comparison incorrectly, thanks for the correction.  However, my mistakes don't make other people's choices correct. 
Quote
In order to reach 118 dB of required dynamic range, he had to take the most extreme percussive classical music, close-mike it, and assume the most acute listener in detecting a noise floor increase. You'd have to have the very quietest part, where noise floor differences might be heard by a few people, before the loud part, because after the loud part nobody would detect such noise floor differences anymore.

This procedure is  only valid if the device being evaluated  is distortion-free. That is,  no dynamic compression,, no modulation noise, no IM, in short no nonlinear distortion of any kind, and no memory effects.  These would be truly golden ears!

Since human ears are well known to have serious problems of these kinds and many more, Fielder's study relates to  mythical perfect ears, not actual human ears.

Re: A Meta-Analysis of High Resolution Audio Perceptual Evaluation

Reply #80 –
Quote from: krabapple on
he thinks his discussion of Type II errors in audio testing is a new thing
I'd like to point out that "concerns" about Type II errors seem to be part of the audiophile pundit narrative.  In so many cases audiophile pundits don't seem to understand that when they make claims of the existence of something it should be their job to show proof of their existence.  Rather, they spend an inordinate amount of time waving away any and all failed attempts at finding unicorns as flawed because no unicorns were found.

Quote from: krabapple on
His take on Meyer and Moran is irritating, though (for the most part*) hardly novel.
Perhaps he could have left it out, just as his meta-analysis should not pay any lip service to the notion that the BS "typical" filters paper adequately demonstrated that people detected quantization effects.

Quote from: krabapple on
My response to the overall 'implication' of this MA -- that in rare cases, some small number of people with documented training appear to be  hearing 'something'
Yes and this deserves attention, otherwise we're just waving hands about statistics over what  exactly?  I'll gladly call it as I see it: a speculative wank fest over nebulous fluff.  It certainly hasn't been shown that this ~55% success rate couldn't possibly have been caused by distortion occurring well downstream from the DSP chain.  And this is then used by pundits as evidence that there might be something to all those claims of veil-lifting, night and day differences emanating from tests that completely fail to account for false positives.  Give me a fucking break!

Quote from: krabapple on
My other take on these results would be  along the lines of his discussion paragraph, where he basically says: more replication of 'interesting results' is needed.  Though he seems to assume that more rigorous work would merely strengthen the implication of his meta-analysis.
I think we need to question why this meta analysis came out not so long after the publication of an "award-winning" paper and subsequent follow-up release of new technology by Meridian.

Re: A Meta-Analysis of High Resolution Audio Perceptual Evaluation

Reply #81 –
As one should know on this forum, there are quite a few studies that indicate that some listeners do detect 24 kHz - and at least one that reports three 28 kHz-capable ears:

... at 100 dB (which means 98 dB over a 2 dB noise floor). Reference [38] in Reiss, open access: http://scitation.aip.org/content/asa/journal/jasa/122/3/10.1121/1.2761883

So if your favourite tune is a 100 dB pure-tone beep, then go ahead spend your golden ears on it. They won't last for too long.
(AFAIunderstand, Ashihara is mainly concerned about damage, not about pleasure.)

Re: A Meta-Analysis of High Resolution Audio Perceptual Evaluation

Reply #82 –
Quote from: greynol on
I think we need to question why this meta analysis came out not so long after the publication of an "award-winning" paper and subsequent follow-up release of new technology by Meridian.
Perhaps the author himself can contribute a hint:
Quote
Audio purists and industry should welcome these findings -- our study finds high resolution audio has a small but important advantage in its quality of reproduction over standard audio content.

Re: A Meta-Analysis of High Resolution Audio Perceptual Evaluation

Reply #83 –
Quote from: pelmazo on
Quote from: greynol on
I think we need to question why this meta analysis came out not so long after the publication of an "award-winning" paper and subsequent follow-up release of new technology by Meridian.
Perhaps the author himself can contribute a hint:
Quote
Audio purists and industry should welcome these findings -- our study finds high resolution audio has a small but important advantage in its quality of reproduction over standard audio content.


Small, yes (if at all).  'Important', that's his spin. 

AFAIK, the paper has been in the works for awhile.  

Re: A Meta-Analysis of High Resolution Audio Perceptual Evaluation

Reply #84 –
Quote from: krabapple on
*I was gobsmacked to see him recite this argument though:  " the encoding scheme on SACD obscures frequency components above 20 kHz and the SACD players typically filter above 30 or 50 kHz"
So THAT's a reason now  why M&M wasn't a good test of audiophile claims? Give me a f*cking break!
This hints to the need of MQA.
Is troll-adiposity coming from feederism?
With 24bit music you can listen to silence much louder!

Re: A Meta-Analysis of High Resolution Audio Perceptual Evaluation

Reply #85 –
Quote
"Audio purists and industry should welcome these findings -- our study finds high resolution audio has a small but important advantage in its quality of reproduction over standard audio content."

Quote from: krabapple on
Small, yes (if at all).  'Important', that's his spin. 

Yes. There is absolutely nothing in the paper analysis, stated or otherwise, about any "audio advantage".
That is, I'm afraid, pure bollocks.
Loudspeaker manufacturer

Re: A Meta-Analysis of High Resolution Audio Perceptual Evaluation

Reply #86 –
Quote
"Audio purists and industry should welcome these findings -- our study finds high resolution audio has a small but important advantage in its quality of reproduction over standard audio content."


Straws, being desperately clutched at?

Re: A Meta-Analysis of High Resolution Audio Perceptual Evaluation

Reply #87 –
Quote from: StephenPG on
Straws, being desperately clutched at?
The university press release, which contains the quote, was picked up and repeated by numerous "sciency" internet media, not just the usual audiophile hangouts. Very few of the readers are likely to actually read the paper, let alone understand the matter.

The audiophile scene has learned to work the system. Similar to the climate change deniers.

Re: A Meta-Analysis of High Resolution Audio Perceptual Evaluation

Reply #88 –
The press release is pure belief (or other), unsupported by the paper. I asked him about this dichotomy and got nothing but waffling. Some crap about Hi Rez sounding more like the "real thing". I guess things like tweeter IM or any system/test generated artifact, is "more real" to believers.
If the alarm bells weren't ringing before.....
Loudspeaker manufacturer

Re: A Meta-Analysis of High Resolution Audio Perceptual Evaluation

Reply #89 –
The press release shows beyond reasonable doubt (IMHO) that Reiss is well aware of the politics of the matter, and is willing to cater to the audiophile agenda, no matter whether his research actually supports any of the audiophile claims.

The audiophile mouthpieces would of course have hailed this study no matter how Reiss himself advertises it, so he could have chosen to remain restrained and stick to the facts, without much difference to the audiophile reception. The bystanders, however, are more likely to accept the message when it comes from the researcher himself. This is what worries me. I think this amounts to a gradual breakdown of ethics in science. It discredits the researcher, even if the actual research should be sound.

But it also discredits science as a whole. It adds to the perception of a lot of people that science is merely a tool in an ideological war. That for every scientific study you can have a counter-study showing the opposite. That the right scientific result can be bought at a moderate price. And that the fake is so hard to detect that you effectively have to trust somebody, so it becomes a matter of subjective preference which version of the "truth" you believe, which of course perverts the very point of science.

Aren't we seeing everywhere how the truth is getting buried under an avalanche of bullshit?

Re: A Meta-Analysis of High Resolution Audio Perceptual Evaluation

Reply #90 –
Quote from: pelmazo on
The audiophile mouthpieces would of course have hailed this study no matter how Reiss himself advertises it, so he could have chosen to remain restrained and stick to the facts, without much difference to the audiophile reception.
Oh they hail, but with unintended consequences too: http://www.audiostream.com/content/its-official-people-can-hear-high-res#PmwEfJPiEh1cBdBR.97
Can't wait to see the triumphant celebrations here http://www.stereophile.com/content/listening-143#kUicFj5BeZwHR4KW.97

cheers

AJ
Loudspeaker manufacturer

Re: A Meta-Analysis of High Resolution Audio Perceptual Evaluation

Reply #91 –
Quote from: ajinfla on
I guess things like tweeter IM or any system/test generated artifact, is "more real" to believers.

Is it even controversial to claim that (edit) including ultrasonic components may cause audible IM distortion?

Re: A Meta-Analysis of High Resolution Audio Perceptual Evaluation

Reply #92 –
Quote from: ajinfla on
Oh they hail, but with unintended consequences too:
Don't know what consequences you mean. The comments?

Funny to see Lavorgna using the opportunity to make a completely unappropriate connection to a paper about Nyquist. He just hasn't a clue what he's talking about, and can't suppress the urge to use everything he can get hold of as a tool against the objectivist side. That's what we have come to expect of him.

Re: A Meta-Analysis of High Resolution Audio Perceptual Evaluation

Reply #93 –
Quote from: Porcus on
Is it even controversial to claim that (edit) including ultrasonic components may cause audible IM distortion?
No, it is mentioned in the paper...which concluded that there is no known cause/correlation for the discrimination.
Unfortunately the AES site is undergoing maintenance this weekend, will have to wait to access all the "made final cut" papers, to assess each in detail, see exactly what was "heard". Familiar enough with nonsense like Ooashi and BS, not with some others or just too far back to recall.

Quote from: pelmazo on
Don't know what consequences you mean. The comments?
Yes, mine, at the very bottom. No response of course. ;) ..from this Mike L http://www.audiostream.com/content/avsaix-high-resolution-audio-test#6o6sOfEk4wAhCBlV.97

cheers,

AJ
Loudspeaker manufacturer

Re: A Meta-Analysis of High Resolution Audio Perceptual Evaluation

Reply #94 –
Has anybody had a closer look at the studies that formed the basis for this meta-analysis?

I just started looking into this, and the first (oldest) study makes me wonder already. The study was performed in Germany by Georg Plenge et.al. and described in an AES journal paper in March 1980. From what I glean from the paper, this was a study made in the analog domain, so no sampling at any frequency was involved. Different bandwidth limiting lowpass filters were compared with each other, to see whether people could distinguish between different cutoff frequencies and filter slopes. Seven different filters were used, with cutoff frequencies between 15 kHz and 20 kHz, and with orders between 7th and 13th, some with group delay correction and some without.

In other words, the bandwidths tested all fall into the range supported by even 44.1 kHz sampling. It doesn't seem to me that the study is relevant to the topic HRA at all. I wonder what business it has appearing in this meta analysis. What am I missing?

Amusingly, the authors conclude their study saying that 15 kHz bandwidth is quite enough for broadcast transmission; the properties of hearing don't justify going to 20 kHz bandwidth. I wonder how they would react if they learned that their study now, more than 35 years later, serves as part of a "proof" that even 20 kHz isn't enough.

Note that Reiss, in his Table 2, lists this study as having a high confidence of having detected differences, with 52.98% correct answers from 2580 total trials. In other words, it contributes substantially to his result, not the least because of the highest number of trials of all studies.

Is this really as bad as it now looks to me? I can hardly believe my eyes! Please show me where my fault is!

Re: A Meta-Analysis of High Resolution Audio Perceptual Evaluation

Reply #95 –
Quote from: pelmazo on
Quote from: ajinfla on
Oh they hail, but with unintended consequences too:
Don't know what consequences you mean. The comments?

Funny to see Lavorgna using the opportunity to make a completely unappropriate connection to a paper about Nyquist. He just hasn't a clue what he's talking about, and can't suppress the urge to use everything he can get hold of as a tool against the objectivist side. That's what we have come to expect of him.

Exactly. I first encountered him on the SP conference site. It's hard to win or change minds when they make up or misappropriate whatever facts they need at the moment.

Re: A Meta-Analysis of High Resolution Audio Perceptual Evaluation

Reply #96 –
I answer to myself, since I now understand a bit better what data Reiss extracted.

The trials in the Plenge study were actually conducted between filter on and filter off, so higher bandwidth than 20 kHz actually was part of the test. Reiss only used the data from 3 out of 7 filters, namely those with 20 kHz cutoff, disregarding those with lower cutoff frequencies. So he didn't distinguish on filter type.

This isn't quite as hilarious as it appeared to me at first, but it is still dubious, for several reasons.

First, the data shows that one of the three filters had a significantly better detection probability than the other two. It was a 9th order cauer filter with group delay correction. This may be a hint that this particular filter had audible properties that didn't relate to the cutoff frequency. It could have been passband ripple or something. Bunching those together to form a single detection probability seems inappropriate to me, because Reiss appears to believe that the differences between those three filters are of no consequence for their audibility.

Second, the test signal was artificial and with very high content of harmonics. Reiss believes that this test signal may not "capture whatever behavior might cause perception of high resolution content". I don't see him providing any argument for that. It looks curious to me, given that he doesn't claim to know what causes HRA to be perceived. Plenge et.al. do provide some reasoning why they chose such a test signal, saying that it presents a worst case scenario that mimics the situation when people listen to music with severely boosted treble. It certainly exaggerates the high frequencies, up into the ultrasonic range, so one would assume that there would be sufficient content to be perceived if it really should be perceivable.

Re: A Meta-Analysis of High Resolution Audio Perceptual Evaluation

Reply #97 –
While I'm at it, I found that barely two years earlier, in April 1978, another study very similar to the one conducted by Plenge et.al. was described in the JAES. It was conducted by Muraoka et.al. in Japan and yielded very similar results. They also compared filters with different cutoff frequencies from 14 to 20 kHz with the unfiltered signal, and came to the conclusion that a filter cutoff frequency from 16 kHz upwards wasn't being detected anymore. They used music instead of an artificial signal, but they also selected material with high harmonic content, i.e. crashing cymbals. The listeners were 30 audio professionals.

A followup study by Muraoka published in 1981 was included by Reiss. Even though the results of their previous study was included in their second paper for comparison, the results taken by Reiss only include those from the second study, which seems somewhat arbitrary to me. The reason would be the year of publication, but given that this is actually a series of studies with very similar setup, I would have thought that this is particularly interesting for a meta study.

A second experiment with sweeping tones was disregarded by Reiss.

An interesting side note is inspired by Art Dudley from Stereophile. He wrote: "If you want a good laugh, go on the Internet and dig up Vol.26 No.4 (April 1978) of the Journal of the Audio Engineering Society, in which various engineers weigh in on the topic of sampling-rate standardization. Two things emerge: The righteous insistence that the world will never require a sampling rate higher than 44.1kHz, and the complete and utter lack of reference to actual listening." This is the exact issue of the JAES where the abovementioned study appeared. Utter lack of reference to actual listening? Heck, the study even used real music, and it had 30 audio professionals actually listening to it! If this is any hint as to how well Art's visual perception works, I can understand why he's emphasizing hearing so much. He's got something to compensate for...

Re: A Meta-Analysis of High Resolution Audio Perceptual Evaluation

Reply #98 –
The Pras Pras 2010 study was very good described by Werner here: So the results of this paper can only be tagged 'inconclusive'...

Another interesting comment at Archimagos blog: On the meta-analysis paper: The Theiss/Hawksford study should have been eliminated...
Is troll-adiposity coming from feederism?
With 24bit music you can listen to silence much louder!

Re: A Meta-Analysis of High Resolution Audio Perceptual Evaluation

Reply #99 –
Quote from: Wombat on
The Pras Pras 2010 study was very good described by Werner here: So the results of this paper can only be tagged 'inconclusive'...
Reiss actually lists it with a probability of 0.1462, which wouldn't qualify as reliable detection when taken on its own.

Quote
Another interesting comment at Archimagos blog: On the meta-analysis paper: The Theiss/Hawksford study should have been eliminated...
I concur with that comment.