What exactly is critical listening? Who does it?

OP, only you can decide if you want to do critical listening--if so, when and why.

I’ve done a lot of it, specifically:

• When I’m writing a review of a headphone, amp or DAC (to post on an audio board ... not a professional reviewer)
• When I’m writing descriptions of the sound of a given DAC, preamp, amp, pair of speakers
• When I get a new (or new-to-me used) component and first hear it in my system
• Or when I hear someone else’s system/equipment

Critical listening is an entirely different mindset from casual or enjoyment listening--the kind I do most often. Critical listening requires less emotion and more analysis, ie, What exactly am I hearing? How can I describe what I’m hearing in words someone else can understand?

Critical listening isn’t fun, but sometimes it’s necessary. And one’s hearing, like any other brain activity, can be practiced and improved, resulting in more focus and awareness of what is being perceived. For example, time spent listening critically helps me indirectly (yet significantly) when I listen to unfamiliar music and try to put it in the perspective of music known to me (perhaps beloved by me). It could be a jazz cut or a classical performance. There’s a halo effect with critical listening, at least for me; sometimes it helps even when I’m not consciously listening critically.

RE: "So, my question is why is this a superior mode of listening, what makes it inherently superior? And why is consciousness of sound quality or qualities necessarily a critical mode of listening?"

I don’t think either kind of listening, critical or pure enjoyment, is superior. Each has its place. Critical listening has it all over enjoyment listening if the goal is to describe the sound to others in ways that they can relate to -- but other than that, enjoyment listening is the default mode, at least for me.

As to your 2nd question: purely my opinion, but when "consciousness of sound quality" dominates one’s mind while listening, this allows one to be critical--as in discerning, receptive, paying attention to all aspects of sound. When I’m doing pure enjoyment listening, of course I’m conscious of sound quality as well, but not in a way that dominates my thinking. Rather, my feelings of pleasure and enjoyment of the music dominate my thinking.

I suppose critical & pure enjoyment listening aren’t mutually exclusve: just a balance that shits to critical or enjoyment in a given circumstance. I have experiences with headphones in particular where I cycle from critical to enjoyment listening and back again. For example, tonight I’ll hear the Verite Open headphone via either the Wells Milo headphone amp (SS, very powerful and smooth) or the Icon Audio HP8 amp (transformer-coupled, an entirely different sound). Switching between amps, I always listen critically at first, to pick up key differences in how the amp sounds vs the previous one. But then I relax back into enjoyment mode.