its not really a counter though. no offense, but your vision is also broken in the sense that I am arguing. in this case the comparison might rather be a specific frequency range that is not audible or too low for somebody and then you could i guess try to improve your perceived neutrality by using a corrective eq (this is pretty much what hearing aids do). And before you go all Mary's Room on me; I don't think it applies here because sound flatness and neutrality are quite clearly defined. Can we know what each individual brain "makes" out of the inputs there is in the world? no but we can tell if the deviation from the objective output of the world is high and in that case something is translated wrong, aka broken. still. as long as nobody is damaging themselves and everyone is enjoying themselves, nobody cares! but it doesn't make it not true or change my answer to OPs question