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
Sorry, Pabelson, I don't think an appeal to the acceptance of a method used in perceptual psychology demonstrates no differences. When there is controversy over a finding, which demonstrably there is, something other than same/different DBTesting would be needed unless those of you persisting in advocating DBT wish to continue to be ignored. I am afraid your argument that DBT proves humans cannot hear the minor differences runs counter to most people's experiences. As I said before, buying decisions don't hinge on scientific proof, and it is an interesting question why some seem so committed to the belief that audio is all snake oil. Perhaps a psychologist should look into that phenomenon.
Qualia: It reminds me of a trick John Dunlavy used to play on visitors to his speaker factory. He would show them an expensive cable (maybe even his own!) and zipcord, and let them audition both. They'd rave about the pricey one, of course. What he wouldn't tell them is that he never changed the cable. They were listening to zipcord the whole time.

One possible weakness of your experiment is that it assumes we know what it is that's tricking us--the price, the looks, etc. But it could be anything (the brand name, perhaps). Also, the value of a perception experiment is somewhat compromised when you intentionally mislead the subject.

There's a much easier way to get over the blindness objection, or at least most of it. In a standard ABX test, you can actually see both cables, and you know which one is A and which one is B. The only thing that's "blind" is the identity of X. Why someone with good ears can't ace this, if the differences are so obvious, is beyond me.

Let me rephrase that: People with good ears CAN ace it--when there's a difference large enough to be heard.
I am afraid your argument that DBT proves humans cannot hear the minor differences runs counter to most people's experiences.

Granted, but why should we assume that the scientists are all wrong and people's observations are right? Surely you know that our perceptions can fool us. Think of optical illusions. Well, there are also such things as aural illusions. One of the most basic is this: When you hear two sounds, you often think they are different, even when they are exactly the same.

So when you say, I hear a difference between this cable and that one, is there a real difference, or is it just an aural illusion? We don't know. That's why scientists developed the forced-choice DBT--because it usefully separates reality from illusion. The only controversy here comes from people who don't want to look at the evidence.
DBT assumes that we have to justify our purchases to others as in science; we do not have to do so
Actually that's an interesting take.
Yet, there's a lot of emotion and correspondingly little logic in the vehement assertions contained in many posts.
Amazing, isn't it. We WANT others to bless our choices after all -- AND, if it's an EE (i.e. scientist) so much the better: science is irrefutable:)
Gregm, I think you are absolutely right that to many of us want others to bless our choices, be it for wine, women, or audio. I stopped going to audio society meetings in New York as too much of the conversations were "mine is bigger than yours" conversations. Having discussion groups on the internet is no different.

My objection to those advocating DBTesting is that they want to use a questionable methodology to say in effect "mine is every bit as good as yours and I paid less." Science does not condone their saying this and I don't really care whether it does or not.

Pabelson, you say, "DBT--because it usefully separates reality from illusion." My only real question is whether the "reality" is a false reality. One that we don't hear when listening. This is why I suggest it is invalid and does not merit acceptance of the findings.