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
Testing the listening abilities of a reviewer...so what are u saying pabelson: that at the beg of each review, a summary of a DBT on the part of the reviewer of the particular equip being tested or listening abilities in general? The latter doesn't seem to work as DBT by nature is specific not broad. So if the former, you would then rule out reading the rest of review, perhaps apart from factual description? Really? I guess you would. Personally perhaps the additional info may be interesting, it does not add that much to me. The reason being again the DBT is for a specific time & enviroment: namely the rest of the control variables...the rest of the system which the reviewer may not be choosing? Or should he? The rest of the system, if for example being constructed with equip unfamilliar to the reviewer, what is he listening to? You may say he only needs to demonstrate that one piece of equip was chged, but in such an unfamiliar setting, our ears could gravitate and focus on something completely else.
Henry: Yes, of course, listening tests are only relevant for the specific gear you're listening to. But a review is about specific equipment. Think of it this way: A reviewer has a reference system. He gets a new amp for review. Can he tell whether his original amp or the review amp is in his system, without looking? If not, is there any value at all to what he says about the sound of the review amp?
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.
In any AB comparison, the two compared signal path elements (components, cables, tubes, etc.) must have at least a week's trial of listening experience before being switched to the other, preferably obver 4 or more such switches.

More immediate AB comparison is not sufficient to reveal subtle but significant differences.

This is because of the nature of auditory perception and its dependence on memory accrued over time (days or weeks, and not hours).

Changes attributed to burn-in are nearly always the result of becoming familar (memory accrual) of a component over days or weeks, for instance - your perception is what changes and not the component.

Imediate AB testing can be downright invalid, and is only useful for detecting large and obvious sonic differences.