After all let's recall that it was Nietzsche who also stated,(I think actually one of his main themes): "Everything is about perception" i.e. the perception of the individual, not what others think and tell...

Next, since we're at it, it was Immanuel Kant (yes the one with the "K") that figured out, what he then called 'a priori'. The basis for us to make sense of our world. If someone tries to tell you that thing over there is motor-bike, and it looks just like a bicycle, no motor I guess, you know it’s BS i.e. it does not fit our bicycle 'a priori'.
You can go look at it from every possible angle and it still remains a bicycle. So much some instant help from nature. (Looks like a duck, sound like a duck, so it’s a duck)

Back to the 4th levels, and I'm not going to give any 4th level perceptions, since in my current universe it’s maybe a bit simpler, maybe.
B U T, something’s amiss in these level descriptions (could have missed it) the OBSESSION with SOUND at the level 3, in disfavor of MUSIC.

Sound at this level seems to become everything, never mind the MUSIC.
I think this is a form of retrogression and infantile, and incidentally the reason, I think, why no person like professional singers, or musician are really falling for it.

You have to be some techno-obsessive individual with your mind sufficiently 'bend' or infused by the 'Technology über alles' mind-frame to go for that.
Given that, it is a form of relieve to hang yourself onto techno-babble, and this measurements only believe, because otherwise it gets just too scary with all music only, and for goodness sake, going with EMOTIONS!

Much safer to hang on to PARAMETERS proper, so long we can measure them of course.

Absents of measurable parameters brings out every insecurity of the techno-mind, now we are at sea and no life saver measurements to hang on to any more.

I think it is for this reason that most audiophiles like to stay in the comfort-zone of level 3.
At level 4 it gets to scary, emotional, undefined, you become vulnerable to attack of level 3 people, 'cause your sound stinks :-).

As a test, when all is said and done i.e. your system sux - tell one how much you liked the music you listened too!
Hey, what was that? No, man but what about the resolution, the depth of stage, tonality, grain, etc. etc.

I think, I mentioned it before, if your system works (for you) you listen to music ONLY, MOSTLY anyway, and all this definition stuff feels more and more like mind-fucking, that takes you away from the real thing -- the music, what it's all about.
It’s a bit like you want to go for a joy ride and the person in the seat next to you keeps on about the tire pressure in