Many, many listening experiments fail to note subtle differences. There are just too many variables involved that I think get disregarded.
My take is that most listening experiments are done with short audio samples for a relatively short duration, often on a system and room the listeners are not familiar with. Add the element of pressure that a listener is supposed to hear a difference at that moment, and the whole experience ends up very different than long term (days and weeks) listening to a good system that you’re familiar with in the comfort of your own home. .

