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Topic: DBT Is Flawed Because Bob Stuart Says So (Read 55147 times) previous topic - next topic
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DBT Is Flawed Because Bob Stuart Says So

Reply #25
I am convinced there are at least SOME situations where they CAN be more relevant, accurate and reliable than double blinded evaluations, even if the differences in sound are said to be "small".


Convinced by what?

DBT Is Flawed Because Bob Stuart Says So

Reply #26
Can we all say "Straw man argument" ;-)

Actually no, you can't...
The reference seems very confused or confusing;

To me, it all seems very perfectly clear.
No!  Counscious(ness) is being aware of one's own existence, sensations, thoughts, surroundings, etc

(two big problems: First the correct form of the word was not used, and secondly consciousness acts over time where time is an independent parameter. Time is not consciousness itself.) These guys are obviously way over their head even entering this discussion!

Eh?

http://books.google.be/books?id=s52lUTjYPH...%22&f=false

http://psycnet.apa.org/books/13261/011
but the actual sensation related to the small detail comes and goes almost instantly.

Says who?
blind tests and A/B switching are completely independent. You can do either independent of the other. Equating them again shows that the people talking are way out of their depth

Where exactly do you see Bob Stuart equating them? 
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is that it doesn’t always eliminate things that we find to be important on a lot of time scales.


Hello! Aren't we talking about hearing small details and not eliminating the perception of them?

We are talking about eliminating bias. I thought so much was obvious...
Actually, it has been found that listening on long time scales erases the reliable perception of small details. The most important use of long term listening is to search for short passages of music where the audible difference we are investigating is portrayed most clearly.

Yes, listening on long time scales CAN erase the reliable perception of small details. However, the same thing applies to listening on short time scales. Both short AND long time scales are important to me, because I normally listen to music for both short and long periods of time. Or were you trying to suggest that musicians ought to not create long pieces of music just because it partly erases my perception? 
All of the confusion I see above IME is greatly helped by true blind testing. Has either done more than diddle around with blind testing? I don't see it here!

No offense, but the main reason why you're so confused IMO is simply because you seem to know very little about the science of psychoacoustics. Well... neither do I, like I already said but, I think I can safely guarantee that Bob Stuart does know one heck of alot more about it than all of the people who replied to this thread combined.

DBT Is Flawed Because Bob Stuart Says So

Reply #27

neither puts it limits in how many times you switch back an forth to determine a difference/preference.

Had you actually even read the interview article, perhaps you would have known that switching back and forth is exactly the kind of thing that inevitably introduces bias except maybe if the test subjects are people who have the memory of a goldfish? 


DBT Is Flawed Because Bob Stuart Says So

Reply #29

neither puts it limits in how many times you switch back an forth to determine a difference/preference.

Had you actually even read the interview article, perhaps you would have known that switching back and forth is exactly the kind of thing that inevitably introduces bias except maybe if the test subjects are people who have the memory of a goldfish? 


Why are you always running away? I've said that it imposes no limits. It does not mean that you *have to*. And if that introduces bias, then, take a rest and come back.
There is nothing innerently wrong in asking the subject if it can correctly identify an item. The only limitations imposed by the ABX test is in avoiding conscious or unconscious preference for one of the items being tested.


Anyway, If that's the only thing of my reply that you find wrong, let's leave it that way and please, specify in which terms (examples or situations) a sighted test can be more reliable than a blind test, as you said in your last sentence, and which you completely avoided to answer at dhromed's request.

DBT Is Flawed Because Bob Stuart Says So

Reply #30
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What if condition A says I can only hear a difference when listening purely for pleasure, condition B says I can't listen purely for pleasure while I'm being forced to listen for differences instead, and condition C says ABX won't work because ABX inevitably forces me to listen for differences? That would be a deadlock situation. It's only a hypothesis, sure. But then, how exactly were you going to prove that the difference I am hearing is called a hallucination? Long story short, ABX and DBT are very valuable tools. They just ain't always perfect for the job.


What if condition A says a person can tell lies, condition B says I can't believe a person if I can't prove he is telling the truth or not, and condition C says non-blind tests won't work because such methods can't prevent a person from telling lies? Remember, what you are doing here is to make other people believe that you can hear the differences. In order to achieve this you need to provide a proof that you are not lying. If you can't, why should I believe you?

DBT Is Flawed Because Bob Stuart Says So

Reply #31
The trouble with ABX testing is always the fact if you want it to be truly objective you have to collect a large enough number of subjective test results to start with, and then apply statistics in order to filter out the unwanted subjectiveness part.


Wow! I've never seen so many critical mistakes in one sentence!

First off there is no intent that ABX tests be objective. The goals are that they be relevant, reliable and accurate. Tests involving listening by people are inherently subjective and that is a good thing. In fact the goal is to involve subjects (people) and in some sense be as subjective as possible.

The reason for collecting modest numbers of test results is to manage the inherent variations in subjective tests near the threshold of reliable detection. If a test necessarily involves a large number of trials, the effect being studied is probably so small that it is actually not significant to normal listening. When something is clearly audible statistical significance is easily obtained with a fairly small number of trials.


You basically just confirmed the whole thing I said.


No, I denied it for reasons that you have not addressed, and now you have added further illogic to the discussion.

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Because the problem with ABX testing is the fact it cannot always be used to produce truly objective results, it cannot always be considered relevant, accurate and reliable.


Excluded middle argument. Nothing in the real  world is perfect or ideal.

In the real world we have sighted evaluations as supported by many are just so horribly flawed in so many of the cases that they are exclusively relied upon! This is even though better alternatives exist and are well known! It is hard for me to believe that so much of what is said by well-meaning but totally mislead people is even said any more!

Since you have raised your criteria for acceptability to utter perfection, please explain how you even get out of bed in the morning? ;-)

Are you seriously telling me that by the criteria of relevant, accurate and reliable, sighted evaluations are indeed perfect as compared to any of the well-known blind testing paradigms as they apply? (note that you have made the common mistake of lumping all blind testing into ABX)


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Quote from:  link=msg=804906 date=0
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This is because every individual test result always has a significant chance of being highly inaccurate, so you need lots of people to participate if you want the final conclusions to be reliable ones.


Wrong. The above is only true for very small differences. Trained listeners can be very accurate and reliable if they are listening to a difference that is even just a little bit above the threshold of audibility.



That is only your opinion.


Just mine, eh? ;-)

No its a fact that anybody can find out for themselves if they are willing to do a little home work.

You aren't very well read, are you?

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What you call "small differences" might very well be less small to me.


I'm not going to go into the world of dueling perceptions with you. The above sentence is speculation without proof or even evidence. It merits no reply.


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Quote from:  link=msg=804906 date=1344677227
One of the more obvious things about listening tests that one obtains from practical experience is that when they involve things that can be actually heard, they are generally fast and easy.

Most of the anecdotes about zillions of trials and frustrated listeners come from people who in retrospect were trying to hear things that aren't audible.


...Or the bias that ABX fails to eliminate is exactly what's causing the fact things aren't audible.


The above sentence doesn't make any sense to me. Please clarify.

DBT Is Flawed Because Bob Stuart Says So

Reply #32
Actually, it has been found that listening on long time scales erases the reliable perception of small details. The most important use of long term listening is to search for short passages of music where the audible difference we are investigating is portrayed most clearly.

Yes, listening on long time scales CAN erase the reliable perception of small details.


Thanks for that!

Quote from: audioclaudio link=msg=0 date=
However, the same thing applies to listening on short time scales.


Proof?

I don't think you've noticed the obvious: If listening on both long and short scales erases the perception of small details, then small details can't ever be perceived. Well that is unless you can figure out how to avoid both situations.

You need to read "This is Your Brain on Music". It lays out the current science about the perception of music. When you've followed up on all of its footnotes, let me know what you think.

DBT Is Flawed Because Bob Stuart Says So

Reply #33
Re. bennetng's post:

Calling someone who refuses an ABX test a liar isn't going to get the discussion very far, though in this case I don't know that it will much matter since it has (again) been steered away from science into the realm of religion. Besides being inflammatory, people suffering from placebo effect actually consciously perceive a difference, just that this perception was not formed from external stimuli that has reached the outer ear.

DBT Is Flawed Because Bob Stuart Says So

Reply #34
No offense, but the main reason why you're so confused IMO is simply because you seem to know very little about the science of psychoacoustics.


You get to be wrong... very wrong!

One obvious fact is that nothing has actually been said about psychoacoustics so far, and yet you brought it up!

Quote
Well... neither do I, like I already said


That's clear, but you seem to be unable to act rationally on that knowledge.


Quote from:  link=msg=804956 date=0
but, I think I can safely guarantee that Bob Stuart does know one heck of alot more about it than all of the people who replied to this thread combined.


Face it, you're a fan!

If Bob Stuart knew very much at all about modern psychoacoustics and believed it, his company's product line would be vastly different and he would have probably made far more real advances in audio.

DBT Is Flawed Because Bob Stuart Says So

Reply #35


First of all, I would like to rewind and set a straight and concrete meaning of several words, since it's not really clear what you're against:

- Objective test/Objectivism ( http://en.wikipedia.org/wiki/Objectivism . In this thread, really http://en.wikipedia.org/wiki/Objectivity_%28science%29 ) : The main idea behind this is that the person doing the test does not matter, since the reality exists independently of the subject taking the test (1 meter is 1 meter no matter who checks it) . Objectivity does make possible to repeat tests and *verify* a result.

- Subjective test/Subjectivism ( http://en.wikipedia.org/wiki/Subjectivism ) : The main idea under subjectivism is that we know the world thanks to our sensory system, and as such, only what we can perceive is what exists (ok. This is just one interpretation. Subjectivism has many variants, from phylosophical, to theological).


I snipped much of your post because it is IMO so good and so non-controversial.

The main point I'd like to make here is that as I understand objectivity and subjectivity which is almost identical to what you posted as far as it goes, they are compatible and actually complement and may even demand each other.

BTW. I see test equipment and test methodologies as "perception enhancers".


The golden ears fail right at this basic point. This was the first point I made in my 2005 debate with John Atkinson. It appears that none of that king's horses and none of that king's men could ever put him back together again. That's because he fell off the fence of Reason so long that his yolk and white had congealed. ;-)

They need for there to be a conflict between the two even though it need not exist. That's just part of the crumbling foundation of their grotesquely flawed dogma. The dogma needs to exist to support their commercial interests. It's all about money, with the irony that if they straightened up and flew right, they'd probably make a ton more money and push Audio miles ahead of where it is.

DBT Is Flawed Because Bob Stuart Says So

Reply #36
Re. Knowledge and belief in modern psychoacoustics:
That's assuming this knowledge actually influenced product development instead of only being used as bonifides in order to market to the gullible more effectively.

DBT Is Flawed Because Bob Stuart Says So

Reply #37
Re. Knowledge and belief in modern psychoacoustics:
That's assuming this knowledge actually influenced product development instead of only being used as bonifides in order to market to the gullible more effectively.



Right, and proof that the above is dominating in the man's life is the fact that he is still flogging the market with an "enhanced CD player".

Considerable evidence was presented in the late 1980s by Masters and Clark and never effectively rebutted, that the good CD players of that day were sonically transparent. The first generation players weren't sonically transparent but most if not all of the audible flaws were tiny and only noticeable under fairly artificial conditions.

People like Ethan and I and some other HA contributors and at least one published, refereed paper in the JAES have revisited this issue several times since then and it still seems to be true.

In a rational world, people would simply leave CD players to people who want to do things like that and move on. Instead many people keep making up and telling fairy tales so that they can continue to flog the market and milk the big bucks from the poorly-informed.

DBT Is Flawed Because Bob Stuart Says So

Reply #38
Meanwhile in a different place our member Julf did a blog entry that relates very well to the things you discuss here. An interesting food for thought imho
http://www.computeraudiophile.com/blogs/ju...c-thinking-246/
Is troll-adiposity coming from feederism?
With 24bit music you can listen to silence much louder!

DBT Is Flawed Because Bob Stuart Says So

Reply #39
I am convinced there are at least SOME situations where they CAN be more relevant, accurate and reliable than double blinded evaluations, even if the differences in sound are said to be "small".

Convinced by what?

By believing in Black Magic. =P

I asked a serious question. Things happened to you that convinced you. I would like to know what these things are. Maybe it was an article you read, maybe it was a thought experiment you did, maybe it was a weird experience with a set of speakers.

DBT Is Flawed Because Bob Stuart Says So

Reply #40
My stance on sighted evaluations is the same as Bob Stuart's, meaning I am convinced there are at least SOME situations where they CAN be more relevant, accurate and reliable than double blinded evaluations, even if the differences in sound are said to be "small".


The evidence against that viewpoint is more than overwhelming. Sighted evaluations are  completely invalidated by a stupendously well-documented, and readily observable tendency towards false positives, except when the difference is outstandingly readily perceptiable. IOW, if you can ABX the difference perfectly with both ears plugged, then it is probably obvious enough that you may not need a blind test to confirm.

Of course the issue of sight in audiophile evaluations is only part of the long list of grotesque problems with almost all audiophile listening tests.

In general audiophile listening tests:

(1) Are not level-matched.
(2) Don't offer close comparisons.
(3) Are often not even done in the same room.
(4) Are often not even done on the same day.
(5) Don't involve using the identical same program material.

GMAB!

DBT Is Flawed Because Bob Stuart Says So

Reply #41
Quote from:  link=msg=804956 date=0
but, I think I can safely guarantee that Bob Stuart does know one heck of alot more about it than all of the people who replied to this thread combined.


Face it, you're a fan!

If Bob Stuart knew very much at all about modern psychoacoustics and believed it, his company's product line would be vastly different and he would have probably made far more real advances in audio.
I'm a fan too - they've also done what even you would probably call "real advances in audio" - e.g. active speakers and DSP.

audioclaudio's implication that Bob Stuart is some sole acting genius, and the individual author of the technologies audioclaudio mentions, is ludicrous - he works with others (often Peter Craven, but you will find many other alumni of audio engineering, past and present, as co-authors on papers and patents). There are actual real world engineers working at Meridian developing and implementing some of this stuff.

I think audioclaudio underestimates the knowledge base here at HA. It would be rude to name drop, but it would be wise if audioclaudio wouldn't assume that one man "knows more" than everyone here.

It would be wise to ignore anything that the marketing department of any company puts out.


The arguments raised against double blind testing raised in this thread are old news, and have been rebutted many times. At the end of the day, it comes down to listening in the same way as you would listen in a sighted test, removing all other variables, not knowing what you're listening to, and checking how likely your answers are down to chance. It's not some mind altering madness inducing torture technique. Or at least, it doesn't have to be!

The unavoidable torture is maybe finding out that, when you don't know what you're listening to, the differences you thought you heard disappear. People may just have to agree to differ on why that happens.

Cheers,
David.

DBT Is Flawed Because Bob Stuart Says So

Reply #42
Quote from:  link=msg=804956 date=0
but, I think I can safely guarantee that Bob Stuart does know one heck of alot more about it than all of the people who replied to this thread combined.


Face it, you're a fan!

If Bob Stuart knew very much at all about modern psychoacoustics and believed it, his company's product line would be vastly different and he would have probably made far more real advances in audio.
I'm a fan too - they've also done what even you would probably call "real advances in audio" - e.g. active speakers and DSP.


Sure they did it, but were they first and was it anything but an obvious application of a technology that was developed by someone else for a different purpose?

I breadboarded a digital music player on a hybrid computer in 1973...  So what?



DBT Is Flawed Because Bob Stuart Says So

Reply #43
It does not mean that you *have to*.

I know that; in fact I never said the opposite.
And if that introduces bias, then, take a rest and come back.
Taking a rest doesn't magically erase my memory. Hence, taking a rest doesn't eliminate my cognitive bias. What happens if I listen to the same music on (1) system A, then (2) system B, then (3) system A again, is as follows. When I'm listening to system B, what I hear is something that's being cognitively biased as a result of what I can remember about how the music sounded on system A. First, let's assume system A is a less resolving system than B. While blinded, I can hear a detail with B that wan't noticeable at all with A. Still blinded, now let's assume I switch back to system A (according to step 3 in the experiment I described above). I can now still hear the detail. Why? Simple. It's because my memory is telling me that B sounded subjectively better, and that that's what the music should sound like. As a direct result from this, my brain now automatically fills in the missing detail where it previously couldn't. It previously could not, because the information required for that had previously not even been stored in my memory yet.

The only limitations imposed by the ABX test is in avoiding conscious or unconscious preference for one of the items being tested.

My above explanation, which is actually Bob Stuart's instead of mine (at least, if I understood the TAS article correctly...), shows that "avoiding conscious or unconscious preference" is not always technically possible if switching back and forth between audio samples is being allowed during these tests.

Anyway, If that's the only thing of my reply that you find wrong, let's leave it that way and please, specify in which terms (examples or situations) a sighted test can be more reliable than a blind test, as you said in your last sentence, and which you completely avoided to answer at dhromed's request.

"If you had the memory of a goldfish, maybe it would work." Seeing something can introduce bias because we can remember what we see, but that doesn't necessarily also mean hearing something can NEVER introduce bias. I can hear things while I'm blinded, things I can remember. I don't have to see what might be causing them to be able to remember that I heard them. So because I can remember them, I cannot always avoid being biased by them. If you don't believe that humans can be biased by things they can remember about a sound they heard, please watch the start of this vid.
http://www.youtube.com/watch?v=BYTlN6wjcvQ

DBT Is Flawed Because Bob Stuart Says So

Reply #44
audioclaudio's implication that Bob Stuart is some sole acting genius, and the individual author of the technologies audioclaudio mentions, is ludicrous

I never implied that he is some sole acting genious, nor that he is the individual author of the technologies. I may be less of a genius than he is, but I'm not THAT stupid. 

DBT Is Flawed Because Bob Stuart Says So

Reply #45
Meanwhile in a different place our member Julf did a blog entry that relates very well to the things you discuss here. An interesting food for thought imho
http://www.computeraudiophile.com/blogs/ju...c-thinking-246/

As a matter of fact I'm a registered user on CA forum too, albeit under a different nick. I've had some public discussions with Julf in the past.

 

DBT Is Flawed Because Bob Stuart Says So

Reply #46
So, audioclaudio, do you notice that you are the only one here arguing against the applicability of ABX testing in proving that a difference is audible? Did you wonder why that is?

Is it A: Everyone else here is so biased that we would discount any evidence presented to us that would counter that belief?

Or is it B: We have been waiting more than a decade for someone to present such evidence, and instead all we have gotten is folks like yourself with lots of theories and conjecture and passing along of everybody else's theories and conjectures?

DBT Is Flawed Because Bob Stuart Says So

Reply #47
As a direct result from this, my brain now automatically fills in the missing detail where it previously couldn't. It previously could not, because the information required for that had previously not even been stored in my memory yet.
Cite the law that says people taking ABX tests are not allowed to practice beforehand in any fashion they choose (e.g.: sighted, blind, standing on their head worshipping the flying spaghetti monster).

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I don't have to see what might be causing them to be able to remember that I heard them. So because I can remember them, I cannot always avoid being biased by them.
...and that's the point! If you can demonstrate your bias while blinded then congratulations, you passed.

I'm not THAT stupid.
Your continued (and lately childish) arguing from authority doesn't paint you as all that smart either.

I've had some public discussions with Julf in the past.
Do you want a medal? I doubt Wombat's post was intended solely for you. While you're the latest uneducated opponent of objective testing, this thread is not about you. In fact, it isn't even about the debate you are trying to have (albeit incompetently). (EDIT: Thanks to the thread split this thread can be about your religious argument and all it's fallacies. )

DBT Is Flawed Because Bob Stuart Says So

Reply #48
And if that introduces bias, then, take a rest and come back.
Taking a rest doesn't magically erase my memory.


True, there is no magic. Erasing small details or rather not holding them long, is how your brain works.

Obviously you have intentionally ignored my advice and have chosen to remain poorly-informed.

Whatever, dude!



DBT Is Flawed Because Bob Stuart Says So

Reply #49
So, audioclaudio, do you notice that you are the only one here arguing against the applicability of ABX testing in proving that a difference is audible? Did you wonder why that is?

Is it A: Everyone else here is so biased that we would discount any evidence presented to us that would counter that belief?

Or is it B: We have been waiting more than a decade for someone to present such evidence, and instead all we have gotten is folks like yourself with lots of theories and conjecture and passing along of everybody else's theories and conjectures?

:cough: It's probably C: Everyone else NOT here has been waiting more than a decade for someone to present evidence to support YOUR theories and conjectures? :cough: