Tone, rhythm, energy, a lot of things.
But not too many people are honest about what they can or cannot hear, or what they are actually listening to.
The whole "there are no wrong answers" thing is bullshit. Of course there are. So an opinion is only as good as what it's based on. So a person who makes a statement about something they're not able to actually hear.. that type of opinion has zero credibility
Be careful with nouns and adjectives, that's all I'm saying.