Doesn't the whole premise of "test anxiety", mood, receptive state, etc all point to how powerful psychological factors/ state of mind are/is? If you being nervous makes you unable to spot the difference between cables the it would outweight any differences the cables had in the first place. And, if they are so powerful, why is it so crazy to think that the entire phenomina is purely psychological?
To me, many of these arguments are self defeating because people are not entirely sure of what they are discussing -which is fine, I will never claim to know everything or even close but psych is one I know well. Telling someone you worry about the mental state effecting the subjects ability to hear critically, then denying the apparent changes are psychological in nature is a little contradictory. The entire arguments cables don't work is one of psychology. Mind over matter and reality.
If you guys go check logical fallacies, and start applying them to the cable debate, you will see an overwhelming number stack on the pro-cable side. So before we even get to the actual testing, the entire logic of the argument is very flawed, on many levels.
Now, to discount the entire concept because there is no evidence would be a logical fallacy too, however when reviewing and argument critically, it should be done impartially and focus on the strength of the argument alone. The argument that cables do not in fact make a difference is an extremely powerful one, and is backed up on many, many different levels. The pro-cable arguments, at the root are logical fallacies. So, the root of the argument is illogical... you get where I am going.
What I wish people would do more often is evaluate peoples arguments, and not their opinion. That would lead to a lot friendlier (and shorter) cable debates.
http://en.wikipedia.org/wiki/List_of_fallacies I got most of them to apply to the Pro-Cable side, and a few to the Anti-Cable side.
In a purely academic sense, the pro cable side would be viewed as nonsense.