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Topic: lecture: Critical listening/evaluation - a path to the future of quali (Read 94039 times) previous topic - next topic
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lecture: Critical listening/evaluation - a path to the future of quali

Reply #50 –
Quote from: Stereoeditor on
The demo of lossy compression consisted of 2 parts: first a "learning" section, where I identified which was the full resolution file and which was the data-reduced file and pointed out aspects of the sound that had changed; second, a single-blind section, using a different piece of music, which followed Phil Hobbs' protocol, where the data density was progressively reduced through the 5 minutes of the piece. The listeners were not aware of what they were listening to and  stood to the side, out of the line of sight while the music played. At the conclusion of the presentation, I asked them to describe what they heard. Almost everyone said they felt the sound got worse, as I described, no-one felt it sounded better as the piece progressed..

Glad you are mentioning this, Mr. Atkinson. I attended Phil Hobbs' "DVD-A - CD - MP3 192 kbps - MP3 96 kbps" demo at the 31st AES International Conference in London two years ago (actually, George Massenburg sat right behind me back then, remarking twice afterwards, "that's a great demo!"). I assume you followed the same format configuration? Did you also prepare a reverse demo, i.e. one with "CD followed by DVD-A"? It would be very interesting to see if listeners could then still hear the difference between the CD quality and the hi-res reproduction. If so, there might actually be an audible difference between the two formats. If not, one could argue that a perceived difference, i.e. sound degradation, between "DVD-A followed by CD quality" was just due to auditory fatigue kicking in.

Side note: In the Hobbs demo I attended, I thought I heard a difference between DVD-A and CD, and I definitely heard a difference between MP3 192 kbps and MP3 96 kbps.

Chris
If I don't reply to your reply, it means I agree with you.

lecture: Critical listening/evaluation - a path to the future of quali

Reply #51 –
ok, so now we have egotism, different commercials and HA rule breaking in one place already, can we please do something like, either:

a. ban somebody
b. close this thread
c. move the thread to recycle bin
PANIC: CPU 1: Cache Error (unrecoverable - dcache data) Eframe = 0x90000000208cf3b8
NOTICE - cpu 0 didn't dump TLB, may be hung

lecture: Critical listening/evaluation - a path to the future of quali

Reply #52 –
Quote from: Stereoeditor on
Quote from: Arnold B. Krueger on
Quote from: Stereoeditor on
Members of a private mail list that includes the above authors of the letter, as well as many other AES illuminati, have been having an active discussion about designing such a test. Far being it simple as you suggest, Mr. Krueger, it seems very difficult to design a test where the _only_ variable is the sample rate _alone.


Only in some people's minds. No doubt the real problem is political, laced with a heavy dose of fear of the dark, along with fear of unfavorable illumination.

<snip>

As usual John, you're ignoring all of the vocal claims from your side of the fence that the audible benefits of higher sample rates are so obvious that only nearly deaf people listening to horrifically made recordings on incredibly bad systems, can't hear them.

The fact of the matter John is that you can't provide a hi-rez example of a typical kind of musical recording with none of the usual tricks that your side likes to pull...IOW, ethical and mental cripples need not apply.


Is it really not possible for you to discuss anything without maintaining a barrage of ad hominem statements, Mr. Krueger?


So John, you again obfuscate your inability to deliver that simple little recording  by whining about the kinds of name-calling that you yourself frequently descend into? 

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The people involved in this effort are hardly "ethical and mental cripples,"


I would sincerily hope so - which is what I meant by: "...ethical and mental cripples need not apply..."


...but include several AES Fellows, some university professors, some well-known recording and mastering engineers, and even JJ.

Right John, so there is a reasonble hope that the kind of highly fallible listening evaluation procedures that you've built your ragazine on won't be allowed.

Quote
And no-one involved, least of all me, has made any accusations of deafness, or having "incredibly bad systems," or using "horrifically made recordings" about people like you who claim not to hear any advantage from bit depths greater than 16 or sample rates higher than 44.1kHz.


First off John, you're making a negative hypothesis - you're projecting that you know every word that every one of these people have said at every time in their lives. This is just as rediculous as your claims that nobody from Stereopile posts under aliases. A reasonable person would admit that you really have no way to know for sure what these people have said and done for every second of their lives.

Secondly John, I never said that *everybody* who is on that task force or that you yourself have ever said such a thing. I said that some people on your side of the fence have said things like that. So now John, are you expecting us to believe that you know what each and every person who is on your side of this issue has ever said? 

John you need to admit that can't provide a recording that unambigiously justifies your religous belief in hi rez recordings.  If you could, you obviously would have by now.  But you can't bring yourself to admit it, presumably not even to yourself. When it comes to your projections of your omniscience or your projections of the validity of your religous beliefs about audio, you are as fact-challenged as many of the openly religious people that you criticize.

lecture: Critical listening/evaluation - a path to the future of quali

Reply #53 –
Quote from: Stereoeditor on
Members of a private mail list that includes the above authors of the letter, as well as many other AES illuminati, have been having an active discussion about designing such a test. Far being it simple as you suggest, Mr. Krueger, it seems very difficult to design a test where the _only_ variable is the sample rate _alone_.


This seems to imply that 'high-resolution' files - which have been commercially available for some not inconsiderable time - have never been robustly tested against 16bit/44.1kHz files. If that is the case, isn't promoting these files as notionally 'better' than 16bit/44.1kHz potentially doing a disservice to listeners?

If and when such a test becomes available, will you publish the findings whatever the results? If the results of such investigation determines that there is no audible advantage over 16bit/44.1kHz files, you will have to make a fundamental volte face in print. Specifically - we heard something that wasn't really there.

Personally, I wouldn't want to stake my reputation on something so provisional.

lecture: Critical listening/evaluation - a path to the future of quali

Reply #54 –
Quote from: C.R.Helmrich on
Quote from: Stereoeditor on
The demo of lossy compression consisted of 2 parts: first a "learning" section, where I identified which was the full resolution file and which was the data-reduced file and pointed out aspects of the sound that had changed; second, a single-blind section, using a different piece of music, which followed Phil Hobbs' protocol, where the data density was progressively reduced through the 5 minutes of the piece. The listeners were not aware of what they were listening to and  stood to the side, out of the line of sight while the music played. At the conclusion of the presentation, I asked them to describe what they heard. Almost everyone said they felt the sound got worse, as I described, no-one felt it sounded better as the piece progressed..

Glad you are mentioning this, Mr. Atkinson. I attended Phil Hobbs' "DVD-A - CD - MP3 192 kbps - MP3 96 kbps" demo at the 31st AES International Conference in London two years ago (actually, George Massenburg sat right behind me back then, remarking twice afterwards, "that's a great demo!"). I assume you followed the same format configuration? Did you also prepare a reverse demo, i.e. one with "CD followed by DVD-A"?


Time was limited, but in most of the Colorado presentations last month, while I did not play a reverse version in full, I did follow the 16/44.1k/128kbps MP3 with 24/88.2k non-compressed.

I was also at Philip's London dem. You can find my resultant comments at http://www.stereophile.com/asweseeit/1007awsi/ . (My apologies to the HA moderators if my providing links is regarded as "commercials," but it really does make more sense to provide a URL to my prior published  comments rather than resort to lengthy and time-consuming cut'n'pastes.)

john Atkinson
Editor, Stereophile

lecture: Critical listening/evaluation - a path to the future of quali

Reply #55 –
Quote from: Arnold B. Krueger on
Quote from: Stereoeditor on
Quote from: Arnold B. Krueger on
Quote from: Stereoeditor on
Members of a private mail list that includes the above authors of the letter, as well as many other AES illuminati, have been having an active discussion about designing such a test. Far being it simple as you suggest, Mr. Krueger, it seems very difficult to design a test where the _only_ variable is the sample rate _alone.


Only in some people's minds. No doubt the real problem is political, laced with a heavy dose of fear of the dark, along with fear of unfavorable illumination.

<snip>

As usual John, you're ignoring all of the vocal claims from your side of the fence that the audible benefits of higher sample rates are so obvious that only nearly deaf people listening to horrifically made recordings on incredibly bad systems, can't hear them.

The fact of the matter John is that you can't provide a hi-rez example of a typical kind of musical recording with none of the usual tricks that your side likes to pull...IOW, ethical and mental cripples need not apply.


Is it really not possible for you to discuss anything without maintaining a barrage of ad hominem statements, Mr. Krueger?


So John, you again obfuscate your inability to deliver that simple little recording  by whining about the kinds of name-calling that you yourself frequently descend into? 


I try very hard to address the argument, not the arguer, Mr. Krueger. If people examine this or the "Audiophiles..." thread on HA, they will note that I have almost entirely been successful at achieving that goal, despite you and others resorting to insults and name-calling, as in the examples I quoted above.

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The people involved in this effort are hardly "ethical and mental cripples," but include several AES Fellows, some university professors, some well-known recording and mastering engineers, and even JJ...And no-one involved, least of all me, has made any accusations of deafness, or having "incredibly bad systems," or using "horrifically made recordings" about people like you who claim not to hear any advantage from bit depths greater than 16 or sample rates higher than 44.1kHz.


First off John, you're making a negative hypothesis - you're projecting that you know every word that every one of these people have said at every time in their lives.


No, I am saying that neither me nor any of the people in the mailing list, which I keep archived, has said anything like you accuse them of in that list's content, Mr. Kreuger. In addition, not one of them, many of whom have been interviewed in Stereophile, has said anything like you have accused them of in print. And not one of them has said anything like it in the many personal conversations I have had with them over the years. If you have evidence to the contrary, please produce it.

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This is just as [ridiculous] as your claims that nobody from Stereopile posts under aliases.


No-one at Stereophile posts to this or any other group other than using their own name, or in the case of Sam Tellig, his long-used non-de-plume. In the, what, 10 years you have been publicly making this accusation, Mr. Krueger, you have not managed to produce one iota of evidence that I am incorrect. Please either produce your evidence or admit that you have no such evidence, Mr. Krueger. Thank you.

John Atkinson
Editor, Stereophile

lecture: Critical listening/evaluation - a path to the future of quali

Reply #56 –
Quote from: Arnold B. Krueger on
And if I subtract  my Difference  from the Original then I get the Recording, which I believe was your question.

So the answer to your question is "Yes".


Thank you, Arnold. I really didn't know whether the maths was as simple as addition and subtraction--that's what I thought, but my mathematical naivety is positively virginal.

Does this, then, mean that you could confound the people who play difference files by playing a file consisting of original - difference, in the confident expectation that there would be no audible distinguishability, assuming you were using a suitable quality of lossy compression for the start of the whole charade.

You could also con people into doing the test single blind by announcing which file was which, but "accidentally" getting it the wrong way round, and correcting yourself later. Ethics? I've heard of them.

lecture: Critical listening/evaluation - a path to the future of quali

Reply #57 –
Quote from: smok3 on
b. close this thread
c. move the thread to recycle bin
Please keep the few posts related to the original topic.


There's a common arguing technique from John - discuss an audible problem (e.g. Pace Rhythm and Timing, noise) - apply it to something like an amplifier where it's usually inaudible, but then justify it using an example where it's clearly audible - e.g. a compressor, or low bitrate mp3.

The implication is that because the problem is audible with the example, it may also be audible in the amplifier.

The idea that something really can be "good enough" is an anathema.


This approach is the antithesis of real engineering, where problems are quantified, and reduced down to the level at which they are no longer problems.


But where's the fun in that? Let's play people 96kps or 128kbps mp3 instead.

(I note people rarely use lame --vbr-new -V2 for demos where they want to demonize mp3 - despite the fact that many of us here can ABX 320kbps! Heaven forbid it should get out that we are far more sensitive to these artefacts than self-proclaimed DBT-shunning audio critics)

Cheers,
David.

lecture: Critical listening/evaluation - a path to the future of quali

Reply #58 –
Quote from: Gag Halfrunt on
Quote from: Stereoeditor on
Members of a private mail list that includes the above authors of the letter, as well as many other AES illuminati, have been having an active discussion about designing such a test. Far being it simple as you suggest, Mr. Krueger, it seems very difficult to design a test where the _only_ variable is the sample rate _alone_.


This seems to imply that 'high-resolution' files - which have been commercially available for some not inconsiderable time - have never been robustly tested against 16bit/44.1kHz files. If that is the case, isn't promoting these files as notionally 'better' than 16bit/44.1kHz potentially doing a disservice to listeners?


Don't be fooled. The testing has been very robust, actually too robust for the promoters of so-called hi-rez audio. That's the problem. They are trying to finagle a deal, but with people like JJ on the scene, their finagling will be to no avail.

Testing where the only variable is the minimum sample rate and word length that the music has been recorded at is the only varable is actually quite simple.  Let the high sample rate musical selection be your reference. There's no problem obtaining a computer with an audio interface that will effectively play it. 

Now, take the high sample rate music and downsample it. Then upsample it back to its origional sample rate.  Verify that timing and signal levels have remained within tolerances (usually automatic). 5 minutes work with any number of different audio editors.  CoolEdit Pro 2.x, which has been around since 2001 or so, will do the job.

Now, you have two high sample rate files to compare. If you can hear a difference then there are all sorts of questions. Was it the downsampling? Was it the upsampling?  However, if you can hear no difference, then there are no questions. The processing where the sample rate was the only variable, was sonically innocent. 

So, all you need is these two files that took 5 minutes to produce,  a copy of WinABX or Foobar or other similar software, and a computer with an appropriate audio interface and monitoring system.

How robust does this test need to be?

Dozens if not 100s of people have done tests like these. The results are that if the test has no other glitches, then the results are null.

But see here, the test I described above  is all science.

What about life in the consumer marketplace? Both SACD and DVD-A were on the market for years and had the opportunity to impress or not impress millions of consumers. They both failed dismally.  At best they have collapsed into minor niche products. They were solutions looking for a problem to solve that turned out to be non-existent. Their brands have no impact and no wider recognition.  The function of high-rez audio has been subsumed into the DTS and Dolby hi rez offerings.  New media such as Blu Ray are just branded with the DTS or Dolby brands and few if anybody knows or cares what is under the brand name. Why should anybody care?


Meanwhile

lecture: Critical listening/evaluation - a path to the future of quali

Reply #59 –
Quote from: MichaelW on
Does this, then, mean that you could confound the people who play difference files by playing a file consisting of original - difference, in the confident expectation that there would be no audible distinguishability, assuming you were using a suitable quality of lossy compression for the start of the whole charade.


Yes. As long as you preserve the files accurately at the bit-by-bit level, you can do the arithmetic and have the desired results.


Quote
You could also con people into doing the test single blind by announcing which file was which, but "accidentally" getting it the wrong way round, and correcting yourself later. Ethics? I've heard of them.


This has been done. Obviously the ethical thing to do is just be up front. But tricks have been played on people.

One such trick happened at a meeting of the audio club to which I belong - SMWTMS.

At once clubmeeting some years back, our host was a very successful car dealer who had made a major investment in high end audio components. He was eagerly demonstrating his new equipment to anybody who would listen. At one point his teenaged son secretly substituted a cheap Pioneer receiver for the high end electronics. His father continued to  eagerly demonstrate his "new equipment" to anybody who would listen, with no clue that the change had taken place. Nobody else heard any difference, either. 

I'm pleased to say that I recently received an email from the son, so no harm befell him as a consequence of his little adventure.

lecture: Critical listening/evaluation - a path to the future of quali

Reply #60 –
Quote from: Stereoeditor on
Quote from: krabapple on
to affect rhythm of a track the smearing would have to pretty damn bad.


It doesn't have be dreadful, just enough to be noticed. Tony Faulkner wrote an article on this subject in the January 2009 issue of HiFi Critic, BTW. Worth reading.



Don't see it on the ToC for the Jan/March 09 issue, but I'll take your word for it that it was there.  But I can't access it.  So, what was his proof of this remarkable claim that the actual *rhythm* of a piece of music is affected by lossy encoding, that would make it worth reading?



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Your demo was dubious for reasons cited already.


Why was it dubious? Levels were matched precisely, the lossy compressed and sample-rate-reduced files were reconverted to 24 bits and 88.2kHz sample rate so that the DAC would be behaving identically with all the examples.

I have answered all your questions before, Mr. Sullivan, in the "audiophiles" thread. Either I can cut'npaste my reponses or you can do the work of looking them up for yourself. (My preference is for the latter.)


I don't bookmark your posts, Mr. Atkinson -- most of which appear to be piddling arguments with Arny anyway -- and here on HA, when you are going to claim *anywhere* that A sounded worse than B, it's incumbent upon *you* to give the details either directly or by link.  Do you just not remember at least what codec and bitrates and sample rates and formats you used, or what?


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Was this before or after the bogus and *highly* biasing 'look a what MP3s leave out!' demonstration?


You mean like George Massenburg's?


Yes, I do mean like George Massenburg's.  His demo,as described by 2bdecided, was misleading too, as I wrote earlier in this thread.

Unfortunately, his demo, as described, was another illustration of the fact that being a revered mastering engineer does not automatically make you qualified to conduct good psychoacoustics tests.  Worse still because I suspect Mr. Massenburg really does know how mp3s 'work', and he should know 'why' they work too...and therefore why 'difference signal' demos are misleading.

Why don't you try to imagine how a demo of 'what mp3 does ' would have been designed and run by someone like , oh, say , *JJ*?


Quote
Because many more people signed up for my demonstrations than the organizers had predicted, I had to omit that example. The demo of lossy compression consisted of 2 parts: first a "learning" section, where I identified which was the full resolution file and which was the data-reduced file and pointed out aspects of the sound that had changed; second, a single-blind section, using a different piece of music, which followed Phil Hobbs' protocol, where the data density was progressively reduced through the 5 minutes of the piece. The listeners were not aware of what they were listening to and  stood to the side, out of the line of sight while the music played. At the conclusion of the presentation, I asked them to describe what they heard. Almost everyone said they felt the sound got worse, as I described, no-one felt it sounded better as the piece progressed..



So here, you're willing to go into detail on protocol, but get cranky when asked what codec(s) and bitrates and samples were used?


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Feel free to disregard the results. But around 200 audiophiles took part in the 10 sessions, which meant that all the listeners could get a good sound, and the overall reaction was very positive, in that people appreciate learning things heuristically under non-threatening conditions.



Probably no surprise to you, but I could care less what '200 audiophiles' thought of such a demo, Mr. Atkinson.

I'm unclear how this test was considered blind, yet apparently consisted of tracks that were *always* progressing from lossless to increasingly lossy.  *OF COURSE* the sound would get worse, if you progressed far enough down through lossy bitrates.  And of course the codec would matter too, as would the samples used.

So, the test makes no sense as described, as a means to demonstrate the idea that lossy always audibly degrades lossless.  Did you compare tracks that stayed lossless to the progressively lossy ones, blind (preferably '*double* -- you standing off to the side really isn't double-blind)?  Did you mark at which bitrates the report of 'difference' kicked in on the progressively lossy ones in the demo you DID do?

lecture: Critical listening/evaluation - a path to the future of quali

Reply #61 –
Quote from: 2Bdecided on
There's a common arguing technique from John - discuss an audible problem (e.g. Pace Rhythm and Timing, noise) - apply it to something like an amplifier where it's usually inaudible, but then justify it using an example where it's clearly audible - e.g. a compressor, or low bitrate mp3.

The implication is that because the problem is audible with the example, it may also be audible in the amplifier.


I agree, but I see a larger problem - the  idea that if something could be imagined to be true, then it surely is true.

One variation is the idea that if an artifact is measurable, then it is of course audible.

Then there's the antithesis - artifacts  either not audible or perhaps even desirable if a property of vinyl or tubed electronics.

Quote
The idea that something really can be "good enough" is an anathema.


The problem here is that once something becomes good enough, it is tough to justify upgrades to it.


lecture: Critical listening/evaluation - a path to the future of quali

Reply #62 –
Quote from: 2Bdecided on
A question from the floor pointed out that an all-pass filter would give an even larger difference signal, but create little or no audible difference (hence the method is flawed in terms of illustrating the audible difference) - George doubted this example.


I find it astonishing that George would not understand this.

He also should have used 192 kbps, or even 256 unless he has an agenda. Oh wait, he said he doesn't have an agenda.

--Ethan
I believe in Truth, Justice, and the Scientific Method

lecture: Critical listening/evaluation - a path to the future of quali

Reply #63 –
Quote from: Stereoeditor on
Try experimenting with a traditional analog compressor or expander. While, of course, the timing of the notes isn't affected, the listener's _perception_ of that timing can be by such a device.


I agree with Tim this is an irrelevant comparison. Yes, compressors have their own timing as they raise and lower the volume level.

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And, of course, lossy compressors set to low bit rates can affect the perceived rhythm of the music. The transient information will be smeared in time.


This too is irrelevant in the context of musical tempo. John, as a musician yourself I can't believe you'd defend PRaT when it's clearly a BS description used by people who have no idea what they're even saying. Indeed, audio already has enough perfectly usable - and better - descriptions.

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the problem is that even a simple descriptor like "muddy" can be due to many different measured errors. It could be due to a loudspeaker cabinet panel resonance, an internal air-space resonance, an underdamped woofer alignment


Exactly! So why "muddy" the waters with nonsense descriptions when the sensible solution is to use terms such as frequency response and distortion and ringing? If our goal is to educate, then let's do a proper job which means use the correct terms. Using PRaT in a discussion about audio is as silly as using the word pee-pee in a sex-ed class.

--Ethan
I believe in Truth, Justice, and the Scientific Method

lecture: Critical listening/evaluation - a path to the future of quali

Reply #64 –
Quote from: krabapple on
Quote from: Stereoeditor on
Tony Faulkner wrote an article on this subject in the January 2009 issue of HiFi Critic, BTW. Worth reading.


Don't see it on the ToC for the Jan/March 09 issue, but I'll take your word for it that it was there.  But I can't access it.


My apologies, I misremembered. It was the December 2007 issue.

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Quote
I have answered all your questions before, Mr. Sullivan, in the "audiophiles" thread. Either I can cut'npaste my reponses or you can do the work of looking them up for yourself. (My preference is for the latter.)


I don't bookmark your posts, Mr. Atkinson...


I had assumed, Mr. Sullivan, that as you were actively involved in the thread where I offered this information - "Why We Need Audiophiles..." between April 25 and April 28 - and had even asked me questions to do with this then forthcoming Colorado presentation, as well as with the blind tests of amplifiers in which I had been involved, you had made note of the information I offered.

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here on HA, when you are going to claim *anywhere* that A sounded worse than B, it's incumbent upon *you* to give the details either directly or by link.


I had assumed that as I had already posted all the information on HA, that the answer to a follow-up question such as yours did not require _re_posting all that information. Perhaps this assumption was incorrect, but otherwise those more interested in trolling than in genuinely seeking information could tie someone up in knots by insisting on strict Tos#8 adherence in _every_ related post.

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Do you just not remember at least what codec and bitrates and sample rates and formats you used, or what?


The sighted "learning" comparison was between LPCM at 24-bits/88.2kHz and AAC at 128kbps, derived from a Red Book version of the data, downsampled using the SRC in Bias Peak 5 at its highest-quality setting, which independent tests had shown to be one of the best-performing (link available on request), and reduced to 16 bits using the POWR-2 redithering algorithm.

The single-blind comparison (using a different piece of music) used first, the original PCM at 24-bits/88.2kHz, Red Book PCM prepared in the same manner just described, AAC at 320kbps prepared from the Red BooK PCM, and an MP3 at 128kbps, again derived from the Red Book PCM version using the Fraunhofer codec in Adobe Audition 1.0. The splices between the 4 different versions were seamless, and there was no indication to listeners other than the possible change in sound that anything had changed. Levels were matched precisely, the lossy compressed and sample-rate-reduced files were reconverted to 24 bits and 88.2kHz sample rate so that the DAC would be behaving identically with all the examples. As I said, this was the exact methodology used by Linn's Philips Hobbs at the 2007 AES Conference.

In the discussion in which you were involved at the end of April, Mr. Sullivan, I told you directly in response to a question from you that I was not intending to present formal DBTs, explaining that "given that these demonstrations are open to the public there may by up to 20 people in the listening room, a formal DBT is out of the question. And please note that, as I keep saying, these are demonstrations, not tests. There will be no scoring of listeners' preference. As I have said, I am only interested in exposing listeners to the the various formats. This is so that they can decide for themselves whether a) hi-rez formats are necessary, b) whether CD is good enough for serious listening, and c) whether the lossy versions are sonically compromised or not. Who could argue that that would be a bad or, in your emotionally loaded term, a 'shameful' thing." (Quoted from my response to you dated April 26, 2009, 10:40am.)

As I explained in later messages in the same thread, I was a) allowing listeners to hear for themselves under optimal conditions if the widespead use of the term "CD quality" to describe lossy-compressed audio was appropriate and b) allowing them to audition hi-rez PCM data under optimal circumstances.

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Quote
The listeners were not aware of what they were listening to and stood to the side, out of the line of sight while the music played. At the conclusion of the presentation, I asked them to describe what they heard. Almost everyone said they felt the sound got worse, as I described, no-one felt it sounded better as the piece progressed.


I'm unclear how this test was considered blind, yet apparently consisted of tracks that were *always* progressing from lossless to increasingly lossy.  *OF COURSE* the sound would get worse, if you progressed far enough down through lossy bitrates.  And of course the codec would matter too, as would the samples used. So, the test makes no sense as described, as a means to demonstrate the idea that lossy always audibly degrades lossless.  Did you compare tracks that stayed lossless to the progressively lossy ones, blind (preferably '*double* -- you standing off to the side really isn't double-blind)?  Did you mark at which bitrates the report of 'difference' kicked in on the progressively lossy ones in the demo you DID do?


I made no claim that the second comparison was double-blind. As I wrote, it was single-blind because while I knew what was being played in the second demonstration, the listeners had no clue to what they were listening, just as in Philip Hobbs' test. The only identification was in the first "learning" example I described. And thank you for agreeing - "of course" - that the degradation in quality should have been audible.

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Feel free to disregard the results. But around 200 audiophiles took part in the 10 sessions, which meant that all the listeners could get a good sound, and the overall reaction was very positive, in that people appreciate learning things heuristically under non-threatening conditions.


Probably no surprise to you, but I could care less what '200 audiophiles' thought of such a demo, Mr. Atkinson.


Oh well. It must remain a mystery, therefore,  why you are so concerned with the details of the test, Mr. Sullivan.

John Atkinson
Editor, Stereophile

lecture: Critical listening/evaluation - a path to the future of quali

Reply #65 –
Quote from: Ethan Winer on
Quote from: Stereoeditor on
...the problem is that even a simple descriptor like "muddy" can be due to many different measured errors. It could be due to a loudspeaker cabinet panel resonance, an internal air-space resonance, an underdamped woofer alignment


Exactly! So why "muddy" the waters with nonsense descriptions when the sensible solution is to use terms such as frequency response and distortion and ringing?


Because you are confusing cause and effect, Ethan. The "cause" may indeed be "frequency response and distortion and ringing" but people do not have any means of directly detecting and identifying those technical abberations. By contrast, the "effect" is what listeners perceive and describe using a familiar vocabulary. This dichotomy was examined, if I remember correctly, in an early 1980s AES paper authored by Subir Pramanik and Soren Bech, in the context of phono cartridge behavior. (I was one of the subjects in the series of blind tests used to generate the raw data for the paper.)

I'll try to find the specific reference.

John Atkinson
Editor, Stereophile


lecture: Critical listening/evaluation - a path to the future of quali

Reply #66 –
Quote from: Stereoeditor on
Because you are confusing cause and effect, Ethan. The "cause" may indeed be "frequency response and distortion and ringing" but people do not have any means of directly detecting and identifying those technical abberations. By contrast, the "effect" is what listeners perceive and describe using a familiar vocabulary.

I don't buy it that PRaT is "familiar vocabulary" John. Those are just made-up nonsense words that should have been rejected by the mainstream hi-fi press rather than repeated. Do we even know where those terms originated? Regardless, they are no more descriptive than "aura" and "energy meridians" and "chakra" etc as often used by AM practitioners.

Perhaps you or I should write an article to explain what the real terms are and what they mean, and include MP3 examples. It's easy to convey rolled-off and boosted highs, mids, and lows, and my Resonance demo video explain ringing, though I admit I probably should do that again using better video gear.

Various types of distortion could be explained and illustrated using audio clips too. I'm serious. This really needs to be done unless you know of such an article or video that exists already. Would you be interested in collaborating on a video like this? Maybe if you and I were both involved it would be more universally accepted.

--Ethan
I believe in Truth, Justice, and the Scientific Method

lecture: Critical listening/evaluation - a path to the future of quali

Reply #67 –
Quote from: Stereoeditor on
I was also at Philip's London dem. You can find my resultant comments at http://www.stereophile.com/asweseeit/1007awsi/ .

Thanks for the link! Now, with all due respect:
Quote
He had prepared four versions of the chorus—the original 24-bit/88.2kHz data transcoded straight from the DSD master; a version sample-rate–converted and decimated to 16/44.1 CD data; an MP3 version at 320kbps; and, finally, an MP3 version at 192kbps—and spliced them together in that order.

What a coincidence that I remember the demo just as you do (even your thoughts during the demo, as you describe them, largely coincide with mine), except for this critical piece of infomation. As I wrote earlier, the MP3s were at 192 and 96 kbps, not 320 and 192. And yes, I'm 100% sure I remember that correctly (and no, I don't have a proof). And yes, there is no reason for me to believe that we heard different configurations at that conference, or that Mr. Hobbs told us different things during the demo. And yes, "as we see it", there is a significant quality difference between 192 and 96 kbps. Coincidence? Accident? Typo?

You are beginning to open my eyes regarding the content of your magazine. So thank you again for the link! No further questions.

To all: sorry for being off-topic again, but I just had to post this.

Chris
If I don't reply to your reply, it means I agree with you.

lecture: Critical listening/evaluation - a path to the future of quali

Reply #68 –
Quote from: C.R.Helmrich on
Quote from: Stereoeditor on
I was also at Philip's London dem. You can find my resultant comments at http://www.stereophile.com/asweseeit/1007awsi/ .

Thanks for the link! Now, with all due respect:
Quote
He had prepared four versions of the chorus—the original 24-bit/88.2kHz data transcoded straight from the DSD master; a version sample-rate–converted and decimated to 16/44.1 CD data; an MP3 version at 320kbps; and, finally, an MP3 version at 192kbps—and spliced them together in that order.

What a coincidence that I remember the demo just as you do (even your thoughts during the demo, as you describe them, largely coincide with mine), except for this critical piece of infomation. As I wrote earlier, the MP3s were at 192 and 96 kbps, not 320 and 192.


I did check both the identity of the music example and the lossy file bitrates with Philip via email once I had returned to the US before I wrote the linked essay. He did confirm that I had them correct. So I don't know why we came away from the conference with different impressions.

John Atkinson
Editor, Stereophile

lecture: Critical listening/evaluation - a path to the future of quali

Reply #69 –
Quote from: Ethan Winer on
Quote from: Stereoeditor on
Because you are confusing cause and effect, Ethan. The "cause" may indeed be "frequency response and distortion and ringing" but people do not have any means of directly detecting and identifying those technical [aberrations]. By contrast, the "effect" is what listeners perceive and describe using a familiar vocabulary.

I don't buy it that PRaT is "familiar vocabulary" John. Those are just made-up nonsense words that should have been rejected by the mainstream hi-fi press rather than repeated. Do we even know where those terms originated?


I did post a link to an article on this subject earlier in this thread, Ethan - http://www.stereophile.com/reference/23 - which examines this subject in considerable detail.

John Atkinson
Editor, Stereophile


lecture: Critical listening/evaluation - a path to the future of quali

Reply #70 –
Quote from: Stereoeditor on
Quote from: Ethan Winer on
Quote from: Stereoeditor on
Because you are confusing cause and effect, Ethan. The "cause" may indeed be "frequency response and distortion and ringing" but people do not have any means of directly detecting and identifying those technical [aberrations]. By contrast, the "effect" is what listeners perceive and describe using a familiar vocabulary.

I don't buy it that PRaT is "familiar vocabulary" John. Those are just made-up nonsense words that should have been rejected by the mainstream hi-fi press rather than repeated. Do we even know where those terms originated?


I did post a link to an article on this subject earlier in this thread, Ethan - http://www.stereophile.com/reference/23 - which examines this subject in considerable detail.


John, exactly what is this religious chanting (taken from the 1992 reference), and how does it relate to audio in 2009?

"For all its quantifiable technical faults, easily identified in the laboratory when compared with the measured near-perfection of CD, the vinyl LP disc possesses a powerful and effortlessly musical content, with an easy, fundamental rhythmic stability and solidity. Interestingly, this innate character seems to be quite robust, more so than digital. Subjectively rewarding results may be obtained from analog sources without much trouble. Many well-established but not necessarily high-priced components may be assembled to produce musically satisfying results. With analog, one can listen through the blemishes and be aware of a strong musical message, one in which the music's flow, pace, and tempo are well conveyed, and into which the listener is drawn."

Based on what is now known about human perception of music, the author's condition is easy to diagnose. He is acclimatized to hearing music with all of the noise of distortion that is inherent in the LP format already added in. The complex path that music takes through his brain apparently only reaches his pleasure centers when they match up with his memories of years and years of listening to vinyl. His memories include the same audible noise and distortion that modern humans find undesirable.  Modern human beings generally lack memories and paths related to the audible aritfacts involved with listening to vinyl. Therefore, even in 1992 the author was writing for only a narrow minority of music lovers who are, by modern standards not interested in high fidelity in the true sense of those words.

lecture: Critical listening/evaluation - a path to the future of quali

Reply #71 –
Quote from: 2Bdecided on
The start was a look at some codecs, playing 192/24 vs 128kbps mp3 (ProTool High Quality - is that FhG based?) - and playing the difference signal - i.e. subtracting the original from the downsampled > encoded > decoded > upsampled version. He played a lot of examples of the noise added by the codec, saying "how can we do this to music?".
It's a pity that he didn't continue with another test: listen to the difference signal from a 24/96 or 24/192 source and its 16/44.1 SRC'd version. Very illustrative IMHO.

lecture: Critical listening/evaluation - a path to the future of quali

Reply #72 –
Quote from: Arnold B. Krueger on
Based on what is now known about human perception of music, the author's condition is easy to diagnose. He is acclimatized to hearing music with all of the noise of distortion that is inherent in the LP format already added in. The complex path that music takes through his brain apparently only reaches his pleasure centers when they match up with his memories of years and years of listening to vinyl. His memories include the same audible noise and distortion that modern humans find undesirable.  Modern human beings generally lack memories and paths related to the audible aritfacts involved with listening to vinyl. Therefore, even in 1992 the author was writing for only a narrow minority of music lovers who are, by modern standards not interested in high fidelity in the true sense of those words.


Good point, and one which would also explain why those who listen to tube amps seem to fall mainly into one of three categories:

a) people of pensionable age (and who therefore spent their formative musical years using tube amps)
b) people who were given dad's tube amp when they started listening to music, or
c) people who are (or were) guitarists, used to playing their guitars through tube amps

lecture: Critical listening/evaluation - a path to the future of quali

Reply #73 –
Quote from: Arnold B. Krueger on
"With analog, one can listen through the blemishes and be aware of a strong musical message, one in which the music's flow, pace, and tempo are well conveyed, and into which the listener is drawn."
[Emphasis Added]

Or one can listen to a CD so they don't have to concentrate on listening "through the blemishes"!
Quote from: Kees de Visser on
It's a pity that he didn't continue with another test: listen to the difference signal from a 24/96 or 24/192 source and its 16/44.1 SRC'd version. Very illustrative IMHO.

Excellent suggestion, but of course they would never do this, because it would be an example of intellectual and methodological rigour.

lecture: Critical listening/evaluation - a path to the future of quali

Reply #74 –
Quote from: Gag Halfrunt on
Quote from: Arnold B. Krueger on
Based on what is now known about human perception of music, the author's condition is easy to diagnose. He is acclimatized to hearing music with all of the noise of distortion that is inherent in the LP format already added in. The complex path that music takes through his brain apparently only reaches his pleasure centers when they match up with his memories of years and years of listening to vinyl. His memories include the same audible noise and distortion that modern humans find undesirable.  Modern human beings generally lack memories and paths related to the audible aritfacts involved with listening to vinyl. Therefore, even in 1992 the author was writing for only a narrow minority of music lovers who are, by modern standards not interested in high fidelity in the true sense of those words.


Good point, and one which would also explain why those who listen to tube amps seem to fall mainly into one of three categories:

a) people of pensionable age (and who therefore spent their formative musical years using tube amps)
b) people who were given dad's tube amp when they started listening to music, or
c) people who are (or were) guitarists, used to playing their guitars through tube amps


Of course there is at least one other explanation - and that is people who are mislead by all of the hype surrounding tubed amps. 

I've got a little patch of psoriasis, and I think that I read someplace that listening to music through tubed amps would cure it! ;-)