We learn from very early on to protect ourselves from pain and unpleasantness. If something is too loud we cover our ears and move away.
On a more moderate scale, we do the same thing when listening to music. If something is too piercing, bright, screechy, or objectionable our ears tighten up as a form of protection.
On the opposite end of the spectrum, when music is natural, open, and inviting, our ears relax. We become more open. We invite in the sounds.
I often think of this as a safety valve. The better the system and the recording the more open the valve.
This observation is intriguing because it suggests our hearing is variable. Unlike the wags who would have us characterized as machines that can be cataloged and judged based on A/B testing in a vacuum, I would suggest circumstances skew those results.
Imagine an A/B amplifier test where a poor recording is employed. Listener's ears are tightened up to the point where they cannot relax and hear into the music.
I have long preached that surroundings, environment, and circumstances play an equally important role as the electronics and recordings themselves.
If our dukes are raised for a fight it's unlikely we can (or should) lower our guard enough to enjoy the music.