With that being said, the first time this question was presented to me was at RMAF 7 (?) years ago when synergistic research was doing a demo on the sound quality of a particular set-up before and after the powercord for the amp was twisted and moved around. It was very easy to tell a degradation in sound after the power cord was disconnected, twisted up and placed back in the system.
Perfect! Because it was moving a Synergistic Master Coupler that brought this to my attention back around 1994. I had two of them at the time and was curious to see if one sounded better than the other. So I swapped them. And sure enough the "new" one sounded worse. (It wasn't really new, had just been used somewhere else.)
But then when the first one went back in it also sounded worse!
Then while I was sitting there listening and puzzling over what had happened a few minutes went by and I was quite sure it no longer sounded as bad. So swapped back. Same thing.
This again was a long time ago. So much experience since then its now taken for granted any moving around at all will have an affect. The more violent the moving, the worse it is and the longer it takes getting back its equilibrium.