I was at a hifi demo of some fancy Wilson speakers a year or so ago. One of the store's sales people could tell the difference of polarity right away. He tried to demonstrate it to the customers, but unfortunately for me I was not able to tell. Perhaps after some time it would be something I could notice. This just goes to show there are things in audio that others can hear even if we can't at the time. I don't think he was making this up. He could walk into the room and would say "switch the polarity" which of course was just a button on the remote. Since each recording could be about 50/50 chances you would be switching this feature a lot as we were sampling all different kinds of music. If you can't hear it, that does not mean it does not matter. Kind of like the tree in the forest.
Why don‘t servers/players incorporate polarity switches
Why is it that most digital servers don‘t incorporate the ability to switch polarity whereas in my experience only ~20% of recordings are in polarity? It‘s a standard feature in Puremusic and other PC/Mac based software and really makes a noticeable difference in sound quality. So much for progress and golden ears...