Why is Double Blind Testing Controversial?


I noticed that the concept of "double blind testing" of cables is a controversial topic. Why? A/B switching seems like the only definitive way of determining how one cable compares to another, or any other component such as speakers, for example. While A/B testing (and particularly double blind testing, where you don't know which cable is A or B) does not show the long term listenability of a cable or other component, it does show the specific and immediate differences between the two. It shows the differences, if at all, how slight they are, how important, etc. It seems obvious that without knowing which cable you are listening to, you eliminate bias and preconceived notions as well. So, why is this a controversial notion?
moto_man
Sean, my response to Hearhere pertained to his/her first post. While Hearhere, in my eyes, appears to be one of the more honorable, reasonable, and sincere of the DBT suporters, there is still a significant insinuation that audiophiles, as group, are subject to powerful forces of deception, along with the insinuation that such deception is prevalent. As for knuckleheads, I would suspect that they are present in both camps. It would be nice if someone could devise a DBT to determine who the knuckleheads are, but for the time being I think it best to determine these by simple subjective discernment. I truly hope I am not getting too nasty with my commentary, sigh.
Wellfed: I was referring to people collected off the street as "knuckleheads". I should have said "average joe's", etc... I do agree with your point though : )

I can't understand why one would want to perform tests on subjects that have no idea as to what they are listening for or how to discern the differences. That is, unless one wanted to promote a certain ideology with the less than optimized test individuals and conditions. Most of the test results that are foisted upon us are those performed upon random individuals, not those that know how to listen and not just "hear". There is a BIG difference as far as i'm concerned.

Even within the ranks of "skilled listeners" you'll have variances as to what people can hear and what they listen for in terms of sonic cues and signatures. As such, if one wanted to make some type of "final statement" as to what was audible and what wasn't, you would have to assemble a very large group of individuals from all walks of life and go from there. At that point, one could start off with simple ( highly audible ) test differences and weed the crowd out from there. As the tests became harder, the "cream of the crop" would be left. At that point, we might be able to say that the average person off of the street will only make it from Point A up to point M in terms of audible discernment. Those that fell short of Point M would be considered to be below average in hearing and / or listening abilities. A select few might make it up to Point S, but anything beyond that would truly require excellent ears and trained listening skills. Beyond that point, it is possible to hear from point A to point Z under ideal conditions by a person with excellent hearing and listening skills. It would be these people that i would use as "guinea pigs" when trying to draw the line between what the human ear and brain is capable of detecting and processing in a linear manner. Does this make sense ?

This approach allows room for growth AND reduction based upon the individual. Obviously hearing and listening skills vary from person to person AND change over time. To me such testing would be logical and i might tend to believe the results a bit more.

If i had to pick and choose an individual to represent "audiophiles" as a group in terms of hearing acuity and listening skills, i would have gone with Enid Lumley circa the late 1970's and early 1980's. I have no doubt in my mind that she was a very skilled listener and had excellent hearing. I'm also 100% certain that she could hear things that i ( and probably most others ) can't. As such, her test results would give me a point of reference as to just how much one could hear and how much i was actually missing. Sean
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Sean, I always thought one of the key features of a true DBT is that the subject does not know the nature of variable element. When applied to audio the listener should not know what to listen for.

I find it interesting that both sides of this issue are strongly suspicious of the motives of the other side. It seems that the interpretation of the results are more controversial than the actual DBT itself.
Those that are administering the tests do not know what is being tested at the very specific time of the DBT, but that does not mean that there isn't some type of log or record that couldn't be taken of such an event by an outside source such as a computer, etc.. Sean
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Onhwy61 -- it is specifically the motivations that yield the controversy. A DBT could, with great effort, be designed to yield reasonably valid results. The posts above suggest that such effort is seldom made because the test sponsors don't understand or believe that effort is required. Without going through all that work, the test becomes a "double deaf test" as Unsound suggests.