Mtrycrafts, your tailored rebuttals are interesting to me. My statements are not a product of being new to audio - I've been active in audio gear and music acquisition for 20 years. However, I have never been a scientist in said pursuit.
Just as a parallel to your 20 years experience. I had a plumber with about the same lenght, taught plumbing and I think he may have been a master plumber, or, claimed to be. Yet, the first words out of his mouth on a call on a water heater thermostat problem was that the blanket I have on the heater will destroy the water heater, rust the tank from condensation as it keeps the moisture in or something. What? a 140degree surface condensing moisture? Went down hill from there. He was a plumber all right, full of voodoo and myths. The 20 years didn't immunize him or give him the right knowledge, after all.
The severity of my statements is wholly related to my own, unscientific experiments.
Time to expand beyond it.
My test is simply after I try a new part/accessory/wire/voodoo, do I hear a difference?
And an unreliable test will yield unreliable results, even after 20 years.
Some of my unscientific experiments have been resounding successes -
Or not. No one knoews for sure. One can only hope and guess.
I have had good luck with updating my cables from cheapies to some that are made much better.
Maybe the cheapies were broken then. Price is not an indicator.
A video tape demagnitizer has been cited to clarify reproduction of CD's and a mat on top of the CD is reported to quiet the noise floor. I have not noted that either of these make any audible difference to me, though I'm still trying them out since they are readily available. 
Waste of time to even try. No science behing them for these issues. Total voodoo. Maybe I should try psychic reading?
Each change, better, worse, or just different, has been incremental. Only a very few things have been revelatory. My really nice preamp is in the shop. Bringing out the old one is a sore disappointment. Same when I had to bring the old CD back from the garage. Harsh, gritty, bright, digital.]
Never know from unreliable protocol to differentiate the sound differences.
My euphonic and unscientific brain is nonetheless analytical. I listen very carefully to see whether the last alteration has brought improvement. I try to be objective.
Without bias controls implemented, you can listen all you want, you will never know the reality as your brain may be making it up as you go, fooling you. You just don't know no matter how objective you want to be.
At the end of the day however, the exercise for me is directed at the enjoyment of music. This personal and self-serving approach to my own system has wrought an immensely pleasing sound, on somewhat of a budget.
Good for you. You are happy. We cannot rely on it though.
I am not an expert on DBT. In fact, I know very little about it. However, based on my lifetime's experience with Hi-Fi, I consider a failure to hear differences in amplifiers an implication of the testing methodology or the human brain itself.
Well, who said amps have to sound different, or any component for that matter? There is no guarantee of this. But we do know from careful experimentation what is reality and what is not. So, it cannot be a failure of the testing methodology. In fact, a failure of the methodology produces more positive outcomes than null or negative outcomes.
But you are correct, the human brain is an integral part and it is well know to have a mind of its own. One reason why eye witnesses are unreliable at trials. I suppose you never asked anyone to repeat what they said just to be told they said nothing? Or, experimented in school to pass on what the teacher said to the next student then they in turn pass it on? Never the input and output to match? Why?
I keep putting a stick in water and it bends. I see have seen this all my life. I even tried a metal pipe, it bends too until I pull it out. A lifelong experience. But now I know it is an illusion only, science has an explanation, not reality, water doesn't bend it.
Of the articles I've read mentioning aural memory, my recollection is that it is on the order of seconds, not months.
That is what I have read as well from reliable sources in the field, yet many golden ears insist on long term listening? No, you didn't imply this, just an ad on here
Since I'm not a scientist, I don't have to back any of this up with data. See? Much easier. If this forum is "Philosophers and Wisemen", I guess I fit into the former category.
Much as the religious believer would say - faith does not require proof, yet I believe.
