Thanks for your input gentlemen. I appreciate it. Yes, DBT testing can and does work in some situations, but when it comes to audio perception habituation, as well as other problems, do occur. Any repetition of a selection, whether sited or not, will cause habituation to rear its ugly head.
It is hard to find partial results such at the beginning, middle and conclusion of such testing. But once in a while such data is given. Here is one example (hopefully this article will stay online).
http://www.bostonaudiosociety.org/bas_speaker/abx_testing.htmNotice the comment
"The tests we took showed clear audibility to a confidence level well over 95% for the first three tests, and null results for the last three."
This is a good example of habituation influencing audio perception and the resultant outcome. (For those who have not read the article, I also cite other problems with AB/ABX testing that need to be accounted for.)
As always I must question the wisdom of any manufacturer who supplies factual information to potential customers as this may tend to confuse them with the truth and lead to fewer sales.
You are probably right Scotty. Maybe I should not have posted the article.