Reviews with all double blind testing?


In the July, 2005 issue of Stereophile, John Atkinson discusses his debate with Arnold Krueger, who Atkinson suggest fundamentally wants only double blind testing of all products in the name of science. Atkinson goes on to discuss his early advocacy of such methodology and his realization that the conclusion that all amps sound the same, as the result of such testing, proved incorrect in the long run. Atkinson’s double blind test involved listening to three amps, so it apparently was not the typical different or the same comparison advocated by those advocating blind testing.

I have been party to three blind testings and several “shootouts,” which were not blind tests and thus resulted in each component having advocates as everyone knew which was playing. None of these ever resulted in a consensus. Two of the three db tests were same or different comparisons. Neither of these resulted in a conclusion that people could consistently hear a difference. One was a comparison of about six preamps. Here there was a substantial consensus that the Bozak preamp surpassed more expensive preamps with many designers of those preamps involved in the listening. In both cases there were individuals that were at odds with the overall conclusion, and in no case were those involved a random sample. In all cases there were no more than 25 people involved.

I have never heard of an instance where “same versus different” methodology ever concluded that there was a difference, but apparently comparisons of multiple amps and preamps, etc. can result in one being generally preferred. I suspect, however, that those advocating db, mean only “same versus different” methodology. Do the advocates of db really expect that the outcome will always be that people can hear no difference? If so, is it the conclusion that underlies their advocacy rather than the supposedly scientific basis for db? Some advocates claim that were there a db test that found people capable of hearing a difference that they would no longer be critical, but is this sincere?

Atkinson puts it in terms of the double blind test advocates want to be right rather than happy, while their opponents would rather be happy than right.

Tests of statistical significance also get involved here as some people can hear a difference, but if they are insufficient in number to achieve statistical significance, then proponents say we must accept the null hypothesis that there is no audible difference. This is all invalid as the samples are never random samples and seldom, if ever, of a substantial size. Since the tests only apply to random samples and statistical significance is greatly enhanced with large samples, nothing in the typical db test works to yield the result that people can hear a difference. This would suggest that the conclusion and not the methodology or a commitment to “science” is the real purpose.

Without db testing, the advocates suggest those who hear a difference are deluding themselves, the placebo effect. But were we to use db but other than the same/different technique and people consistently choose the same component, would we not conclude that they are not delusional? This would test another hypothesis that some can hear better.

I am probably like most subjectivists, as I really do not care what the outcomes of db testing might be. I buy components that I can afford and that satisfy my ears as realistic. Certainly some products satisfy the ears of more people, and sometimes these are not the positively reviewed or heavily advertised products. Again it strikes me, at least, that this should not happen in the world that the objectivists see. They see the world as full of greedy charlatans who use advertising to sell expensive items which are no better than much cheaper ones.

Since my occupation is as a professor and scientist, some among the advocates of double blind might question my commitment to science. My experience with same/different double blind experiments suggest to me a flawed methodology. A double blind multiple component design, especially with a hypothesis that some people are better able to hear a difference, would be more pleasing to me, but even here, I do not think anyone would buy on the basis of such experiments.

To use Atkinson’s phrase, I am generally happy and don’t care if the objectivists think I am right. I suspect they have to have all of us say they are right before they can be happy. Well tough luck, guys. I cannot imagine anything more boring than consistent findings of no difference among wires and components, when I know that to be untrue. Oh, and I have ordered additional Intelligent Chips. My, I am a delusional fool!
tbg

Showing 9 responses by gregadd

I sent the following letter to Sterophile:

Those of us who have been audiophiles for a long time(20+ years) have chronicled the progress of audio components. We have gone down the wrong road too many times to count. Either led there by others or led by our own ignorance and prejudice. We need to remember that while for the consumer this is a hobby for the producers it is a business. Producers must make a profit or die.The road to hi-fi perfection is littered with excellent products whose producers did not pay attention to normal business practices.
Audio producers have to fight for market share like anyone else. The best way to get market share is through aggressive advertising. Build a better mouse trap and they will come to you. Design a slick ad campaign and they will also come to you. There is a problem however. The audio reviewer. If done correctly, it seeks to pick the best mouse trap and debunk the advertising myths. Like manufactures the magazine is also a business and it must make a profit or die. Even worse it's profits come primarily form the very producers it seek to evaluate. A canceled subscription hardly competes with a canceled ad. This puts an ethical strain own the most principled reviewer.
Audiophiles aren't stupid. This a hobby. We are not just interested in good music. We like our components to come in beautiful packages, exclusivity, etc. Just because we purchased something unnecessary does not mean we were tricked. I am sure the piano black finish on my turntable has nothing to do with the sound. Does that mean I was tricked?
From a consumer standpoint if a manufacturer claims that his product sounds better or different it is the reviewers job to evaluate the manufactures claim.
Most reviewers want the manufacturers claim to be true. The reasons are obvious. They recommend a better product to their readers, the state of the art is advanced and the manufacturer can buy ads. Negative reviews save their readers money and nudge producers in the right direction and establish their credibility.
Ironically everyone can't be right. Being right or wrong has serious financial consequences for all involved. Reviewers have been wrong. Manufacturers have been wrong and sadly some have tried to rig the process. More often than not mistakes are based on ignorance and prejudice. Ignorance must be cured by the ignorant, and corruption should be prosecuted. Maybe we can do something about prejudice?

If we did not know what product is being tested we could at least eliminate our personal prejudice. Nothing wrong with double blind testing(dbt) per se. The proponents of dbt bring their own prejudices to the table. They want to engage in very short tests conducted by the uninitiated. Most proponents of dbt use it to try and prove what they already have concluded.eg cables and amps all sound the same. And that expensive products are just a rip off. How about a dbt between vinyl and digital. Or electrostatic and dynamic speakers- tubes and solid state.
The opponents of dbt are also somewhat disingenuous . I do not need dbt because I am not prejudiced. It is the nature of prejudice to not be aware of it.. The person who is prejudiced just thinks he is right.
The design of components is a mixture of art and science. The reviewers job is almost all art Some things just don't lend it self to scientific testing. Could you have a dbt of who is the most beautiful women or what piece of music is the most soothing.
Alas dbt does not even approach the real question. What difference does it make to me whether a &b sound different or the same. My point is which one more closley approximates the illusion of real music for me. Hasn't that always been the goal for audiophiles.
I have always stated that dbt is more a test of sonic memory, the better your memory the better the better you will test.
If you read this carefully you are going to be surprised by my conclusion. Everyone who is involved in audio design or review should from time to time engage in some sort of dbt testing! Your goal should be to determine which product sounds more like music. You may discover biases you did not know you have. Take your time. Make your dbt as much like your regular evaluation process. I think you will benefit from it.
Reginald G. Addison
rgregadd@aol.com
Forestville, Maryland
my new policy on audiogon is to post my opinion and let it stand on it's own merit. I no longer feel the need to respond to every competing opinion. I'll let the readers make thier own conclusion. I do however reserve the right to respond crticism directed at me.

My approval of DBT is in no way an endorsement of the ABX test.

Just because you beleive in DBT or ABX testing does not make you an objectiive. DBT proponents have yet to show me where they have used it to advance the state of the art. They are as biased as anyone else. In fact the inventer of the ABX gave this as his reason for inventing the ABX box-he was upset that audio companies could be destroyed by audio reviewers who did not know what they are talking about. Thus DBT/ABX was invented to attack the integrity of audio reviewers. Not as an objective scientific tool.

The intial tests where short term on inexperienced listeners. That is a fact. To furhter demonstrate thier lack of objectivity it is the proponents of DBT/ABX, when confronted with the fact that reviewers like Michael Fremer were in fact able to match A&B to X, attacked the validity of thier own test. In effect they concluded that because they knew there was no difference between amps he must be using some trick formulated by his knowledge of the amplifiers under test.
No one argues that amps and cables sound the same. Nothing is further from the truth. That is exactly what they argue calling it snake oil and making vial insults to those who design, sell, buy and review it.

Feel free to remain wedded to frequency response, distortion figures and output impedance if you like. You don't need a blind test for that because it is so easily measured. You may clean your palette with the occaisional blind test. Ultimately you are going to have to listen. This is what all the manufactures of good equipment do.
Let me try this one last time.
Just because you beleive in DBT/ABX doesn't make you objective. Every so called objectivist uses BDT/ABX to prove what they already beleive. when the test fails to prove what they already belive i.e all amps sound the same except for some easily measurted and compensated for parameters t deem the rewsults statisically insignificant. To me that is bias which is what we are talking about.
DBT has only two purposes, to eliminate perssonal bias and the placebo effect. When you have done that you are just getting started.
The real question is does a the component under consideration simulate real music. As crazy as it may make you only the human ear can evaluate that.

That I never conceded that A/B testing of any kind was signifcant. Buying A because it is better than B is a Madison Avenue trick! I was lucky enough to be taught that. It has saved me a lot noney.

Pableson-The DBT/ABX does not measure what sounds good or bad it only measures whther the listerner can identify a or b when comapred to x.

Its' not that we think ABX is not good enough. we think it's irrelevant.

It's been my experience that dealers are more of a slave to the audio press than audiophiles have ever been.

Finally reviewers are not scientist they are critics who give opinions as a guide. If audiophiles are taking thier opinions as gospel, they should trust thier own ears.
.. and by the way I am deeply troubled by your of the terms sounding good or bad. Those are decidely subjective terms.
Just what scientific test did you use to come to that conclusion?
No I don't think they should dbt because even when the reviewers pass the test so called objectivist don't accept it.

Pableson- No they should not be kept in the dark about the reviewers ability.
You assume that ABX/DBT is the standard by which everyone must be measured. I categorically reject that premise! Therefore I cannot answer any questions that require me to accept that premise.

As a long time reader of audio component reviews I am aware of thier shortcomings. However the overwhelming majority of reviewers admit that they are fallble and that they have listening biases. Thier review is thier personal opinion. Thier goal is to identify components which they believe bring us closest to the reproduction of music.

Let's take the absolute sound for example when Harry Pearson still owned it. They periodically published their background, room dimensions, personal listening biases and associated equipment.
Once they have identified an audio component as having merit it is then the readers job to make his own evalaution. This is true for any critic. If the critic is consistently wrong ultimately the readers will go somewhere else for opinions.

They way I evalaute a reviewers ability is to listen to components they have recommended to see if thier opinion is valid. If I can't duplicate thier experience on a consistent baisis then I have to doubt thier ability.
I know of no one who requires anyone to take a mini test to establish thier credibility before they perform the real test. That would be tantamount to my being required to be successful in a little mini-trial before I do the real thing.
This would be equivalent to asking your Doctor to examine two patients whose illness was known in advance before he could examine you. It would not be practical and it would not prove anythig.
Furthermore one person passing a test does not prove antyhing. The sample group would have to be of sufficient size. One person's success or failure could be easily discounted statistically. Thus if say Harry Pearson took the test and scored a perfect score his results could easily be invalidated. The majority of the other reviewers could flunk or have a statisticaly insignificant number of successes which would mean his success is a statistical abberation. That sort of heads I win, tails you lose logic does not work.
This time I mean it. If you listen the results should be obvious, if not don't buy. I have nothing else to say.
As they say in the neighborhood where I grew up..."it's on now."
Pay attention Pabelson. I did not give a history of DBT which I concede can be a useful tool in revealing prejudices but ignores the real issue. I gave a history of the ABX Comparator. In fact DBT and ABX arrived on the Audio press simultaneously.
You are quite correct Mr. Fremer's results are in fact not a mystery. He proved he could hear the difference.
If you want to know my principal source for the history of ABX it was primarily the Audio Critic written and published by one of the most serious advocates of DBT/ABX Peter Aczel.
Both Mr. Fremmer and myself suffered a personal attack in the letters column. It appaears Mr. Fremmer was not qualified to criticize DBT/ABX because of his sloppy wiritng style. I of course was unworhty because I was a DC trial lawyer.
Like you, when confronted with Mr. Fremers' test results Mr. Aczel refused to acknowledge that Fremer could match A&B to X in a test designed by others, where frequency reponse distortion , output levels,etc. were all accounted for. He tried to wiggle his way out but was unable.
I of course dared to challenge Mr. Aczel to put his money where his mouth was. He was using a top of the line Boulder amp. I offered to trade him his Boulder for the generic Radio Shack amp of his own choice with an equlizer so he could compensate for any frequency reponse violations. In fact I told him he could keep his amp and I would give him the Radio Shack amp of his choice if he promised to use it as a primary reference.
His response was that I knew he could not accept the offer becasue he needed a top qulity amp for his test. He then accused me of conducting a cheap trick. He said this trick may work on a DC jury but not on him. This transpired in the late'70's or early '80's. Harry Pearson published the first letter in the absolute sound.
Pableson while I may make mistakes, I don't indulge in falsehoods.