the relationship between anticipation and perception has been the subject of a good deal of psychological research. anticipation is a process based on the perception that something is going to happen in the future. all living organisms, including humans, use anticipation to guide them in goal-oriented decision-making. It's what makes it possible for us to perform different physical and mental tasks without measuring everything along the way.
this doesn't mean that one cannot hear a difference between cables and interconnects, only that what one hears (or thinks he hears) is partly the result of anticipation. when we add to the mix the high cost of some of this equipment, we can expect the role of anticipation to be even greater.
if you want to be more convincing to others about the improved quality of a cable, you must due to blind study in which someone else switches the cable, leaving you with the job of simply perceiving what you hear. of course even then, the anticipation of the experiment could influence the outcome. better to have someone sneak into your home and replace your cables without your knowledge. in the name of science, i'd be willing to conduct this experiment for you. just send your keys to me, along with an idea of when you'll be away, and i'll do the rest...for science.