3d - no we dont have to have an absolute reality. I studied general relativity and I can assure you that this is not the case. The world of quantum uncertainty compounds this at the other scale (which is itself further compounded at relativistic velocities re: certain types of radiation and hence observation that are dependent on the viewpoint). In addition some of your statistics is a little shakey. Beliefs of the subjects in the experiment can be counted for by calibration, examination of bias and rigourous controls and placebo studies. The controller of course must not be one of the people in the experiment. What you are desribing is no longer a test of cables it is a test of peoples propensity to hear differences when none exist due to expectation - something that has to be eliminated in a cable trial. It is a bias introduced by the testing method that can easily be measured and eliminated. An interesting psychological experiment but not one about cables.
In any "16 out of 20" test the statistics should of course be agreed by both parties beforehand.
In any "16 out of 20" test the statistics should of course be agreed by both parties beforehand.