Being a true scientist, I do not need a scientific explanation in order to observe something happening. Here's a little experience I had with a cable, from which you can draw any darn conclusion you like.
I was putting a new system together and using Alpha Core MI2 Python Speaker Cable. I perceived the system too sound a little too warm and lacking immediacy. I then bought a pair of used Coincident TRS speaker cable, in the expectation that it would eliminate the problem. The TRS was put in the system on a Thursday, and immediately I perceived the sound to be thick and lumpy in the bass, with some thickness in the mids too. This was directly after listening with the Alpha Core in place. So the sound seemed to go noticeably in the wrong direction when the TRS was hooked up.
By Saturday I was perceiving the sound to be opening up and beginning to provide much more detail and more articulation. Round about Saturday evening the I perceived the sound had gone too far and that the upper mids were etched and dry. I persisted with the cable through to the following Thursday but was getting frustrated at how I was enjoying none of the music. The TRS was now consistently irritating me with an apparent harshness in the upper mids, almost unlistenable. I was not surprised at the change in apparent sound since I have experienced it before with second-hand cables that had travelled thousands of miles but I was hating it so much, and had hated it every day for 5 days, that I took the TRS out and put the Alpha Core back in. The Alpha Core sounded to me exactly as I remembered it - nice but a little too warm and lacking immediacy - but mercifully musical and very welcome after the horrid experience with the TRS.
About a week or so later I put the TRS back in the system. It sounded pretty good to me immediately - more detail than the Alpha Core and just as musical - and it seemed to get better over the next three days. After a week I was very satisfied with it and felt the system was sounding just right - which it has continued to do over the months since then. So I had to try the Alpha Core again - sure enough the Alpha Core sounded to me exactly as before. But going back to the TRS, the perceived improvements in detail, immediacy, etc were noticeable, and really made the system boogie. No perception of harsh upper mids at all - totally gone.
So how come the perceived sound of the TRS moved about so much? It appeared to go in one direction, then another, then wound up on the button! Yet the Alpha Core, despite being stored did not seem to change at all.
Funny thing though, my wife observed the exact same phenomena that I did - noticing each change that I described above. She wanted me to ditch the TRS but now agrees it is better. Yet she listened only about 25% of the time that I listened for. So if the effect is psychological, then either; my wife needs 75% less time to get used to the sound of a new component than I do; or elapsed time is the factor not listening time; or my wife senses how I feel about a component and, unprompted, manages to state what I think (could be true, these females are perplexing indeed "life Jim, but... " thinks... maybe she fakes in bed too..); or, perhaps something about the sound really did change. Each of these explanations is quite fantastic given what we know. Hence, perhaps, the answer lies in something that what we do not know.