Regarding the Randi challenge, I repeat what I've said before: it is good science to calibrate a test apparatus before a test is attempted. I'd expect a pre-cable trial run, therefor, in which it is demonstrated that the test set-up is good enough to allow reliable detection of small sound differences which should be audible according to accepted wisdom. Sadly, I see no mention of this in the Randi "challenge".

Fwiw I think the Randi challenge should be held in a controlled environment run by a reliable third party, where neither Mr Randi nor the participant have control of the set-up. The Canadian sound research body (I forget the name) or perhaps the Harman test room come to mind.