IPB

Welcome Guest ( Log In | Register )

DBT Is Flawed Because Bob Stuart Says So, Split from Topic ID #11442
2Bdecided
post Aug 6 2012, 11:22
Post #1


ReplayGain developer


Group: Developer
Posts: 5057
Joined: 5-November 01
From: Yorkshire, UK
Member No.: 409



I don't think it's helpful criticising someone for not running proper DBTs of loudspeakers. As far as I know, only one or two members here have tried.

I know the loudspeaker comments were part of a longer post that had many other issues, but I don't think ABX-ing loudspeakers is a realistic thing to jump on.

Cheers,
David.
Go to the top of the page
+Quote Post
 
Start new topic
Replies
audioclaudio
post Aug 8 2012, 20:17
Post #2





Group: Members
Posts: 33
Joined: 3-December 11
Member No.: 95560



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. 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.
Often, if not practically always, it is too time consuming and/or too uneconomical to conduct an ABX test properly, i.e. in such way that expectation bias doesn't creep in through the back door etcetera. Experts in auditory neuroscience and psychoacoustics have gathered experimental evidence which appears to indicate the following. Humans who remember different things are perfectly capable of hearing the same sounds differently as a result of remembering different things. For example, Bob Stuart of Meridian, who has a Ph.D in neuroscience, believes that it is perfectly possible for a person to not hear a specific detail in a piece of music when it is played back on one particular system "A", then to discover this specific detail by listening to the same music again on a better, more resolving system "B" next, and then, finally, to turn back to the previous system "A" and always hear this detail on system "A" even though the detail could previously not be heard on system "A". Moreover, Bob Stuart believes rapid switching between sounds can inevitably cause humans to perceive sound objects differently.
Go to the top of the page
+Quote Post
audioclaudio
post Aug 9 2012, 19:12
Post #3





Group: Members
Posts: 33
Joined: 3-December 11
Member No.: 95560



QUOTE (greynol @ Aug 9 2012, 00:42) *
QUOTE (audioclaudio @ Aug 8 2012, 14:20) *
I don't know why you disagree on the fast switching part, because there appears to be substantial evidence to support it.

I guess I'd have to take your word for it on that one.

Well, I said "there appears to be" because I am no expert on the matter. There was a TAS interview by Robert Harley with Bob Stuart about it, which was published some years ago.
QUOTE (greynol @ Aug 9 2012, 00:42) *
QUOTE
With rapid switching, this natural process does not occur.

You seem to misunderstand an extremely important part about ABX testing: ABX can only be used to objectively demonstrate differences. A failed test does not prove two things sound the same to all people under all circumstances for all time.

No, I understand this and I am not trying to argue against it. However, it implies that, if Bob Stuart is correct about the consequence of rapid switching, ABX might not be capable of demonstrating differences which could be easily noticed in listening sessions during which the natural process would be given the time and chance to occur, so, again, this would indicate ABX is generally very often too time consuming and/or too economically unfeasible.
QUOTE (greynol @ Aug 9 2012, 00:42) *
QUOTE
My point is, if even world's best experts fail to come to an agreement on what's required to be able to design a reliable ABX test, which IMHO appears to be the case BTW, then who are we to judge those who are skeptical towards the objectivists?

I can come up with all sorts of fanciful things that you cannot disprove. Will you be giving me the same credibility?

This is exactly the problem I was actually trying to describe. If nobody had looked for planets outside the Solar System, nobody would have ever discovered any. That is what science is, or ought to be, all about in the first place. Without science, there can be no objectiveness. If I have to name one thing I have in common with Bob Stuart, it's the fact we both don't believe in Black Magic (and we both love music). laugh.gif
QUOTE (2Bdecided @ Aug 9 2012, 12:11) *
Many of these "problems" apply to any listening test where you must compare two sources and decide what you think about them - and that includes sighted listening tests! Therefore it's wrong to raise these "problems" as criticisms of ABX/DBT.

Yes, I believe that is entirely correct. It partly explains why I usually prefer not to partake in any listening tests of any kind whatsoever. I am in the same camp as Robert Harley about them. Meaning, differences between sounds are magnified when I listen purely for pleasure rather than for making comparisons. I know, it may seem a little bit strange perhaps, but nevertheless, it's true.
QUOTE (pdq @ Aug 9 2012, 13:44) *
QUOTE (audioclaudio @ Aug 8 2012, 17:20) *
QUOTE (pdq @ Aug 8 2012, 20:51) *
I'm sorry, but how is any of this "the trouble with abx testing"? Rather this is the trouble with determining what is right and wrong when differences are subtle, and abx testing is the tool that makes this possible.

Yes, it is the tool that makes this possible, at least in theory. However, in practice, it is typically more often than not extremely difficult to find enough people who will participate in such testings.

It's actually quite simple. Person A claims to be able to hear something. If he then voluntarily takes an ABX test for, say, a dozen or so trials, he either has provided statistically significant results that support his claim, or else his claim is unsubstantiated (though not necessarily false). Unsubstantiated claims remain just that, unsubstantiated.

Obviously. Like I said though, I suspect that alot of these "unsubstantiated claims" remain unsubstantiated only because ABX itself is what can severely impair one's ability to "hear something", and that this could perhaps help to explain why alot of knowledgeable people, including a fair number of experts (there's that dirty word again...), are leaning more towards, or at least are not so very skeptical towards, the subjectiveness part of the picture than some others might find logical.

This post has been edited by audioclaudio: Aug 9 2012, 19:14
Go to the top of the page
+Quote Post
greynol
post Aug 9 2012, 19:48
Post #4





Group: Super Moderator
Posts: 10000
Joined: 1-April 04
From: San Francisco
Member No.: 13167



QUOTE (audioclaudio @ Aug 9 2012, 11:12) *
If nobody had looked for planets outside the Solar System, nobody would have ever discovered any. That is what science is, or ought to be, all about in the first place.

How does requiring objective confirmation of claims prevent curiosity?

QUOTE
Meaning, differences between sounds are magnified when I listen purely for pleasure rather than for making comparisons. I know, it may seem a little bit strange perhaps, but nevertheless, it's true.

The needle on my placebo effect meter just pegged.

Funny how otherwise obvious differences vanish under scrutiny, isn't it? wink.gif

QUOTE
ABX itself is what can severely impair one's ability to "hear something"

rolleyes.gif
That this is it true is highly questionable. Next time you present a "fact" I recommend supporting it with evidence rather than anecdotes.

While there may be a limit on one's patience and/or resources which may hinder proper ABX testing, ABX testing does not require arbitrary time limits. This tired "time limit" excuse still doesn't change where the burden of proof falls when pitting theories that are corroborated with little or no evidence against theories that are corroborated with evidence or are falsifiable but have yet to be falsified.

Regarding "experts" I can find some who say global warming is not real. I don't know of any in this camp who don't also have some kind of incentive to hold this position, however. You might consider whether the same can't be said about some of these neuroscientists. Of course some kind of vested interest doesn't necessarily mean that they are wrong either. The point is that expert testimony can be cherry-picked.

This post has been edited by greynol: Aug 10 2012, 00:57


--------------------
YOUR EYES CANNOT HEAR!!!!!!!!!!!
Go to the top of the page
+Quote Post

Posts in this topic
2 Pages V   1 2 >


Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 



RSS Lo-Fi Version Time is now: 22nd July 2014 - 12:01