My point, tongue in cheek, was that the differences are real, they're quantifiable, they're repeatable, and to be sure, measurable, IF we bothered to characterize the complex transfer function comprised of subtle phase, frequency, and amplitude anomalies.
Those measurements are undoubtedly very small. The human ear is an incredible instrument with truly remarkable dynamic range capabilities. A trained ear can instantly discriminate when there is a phase, frequency, or amplitude anomaly at work in a sound system that is completely inaudible to an untrained ear, even when that anomaly is pointed out repeatedly.
It is precisely by this training that I discovered that the channels of my SAC amp were wired out of phase with one another the instant I first heard it. Yet SAC themselves had produced who knows how many copies with the same defect and for who knows how long they’d been on the market, yet nobody said a word. They simply assumed that the amp didn’t sound very good I guess and sold them off to one another quietly hoping it would all go away. When I first noticed the problem and corrected it in my amp, I published my findings, and even those who sold the amp commercially, denied that such a thing could possibly be, for quite some time. As I persisted in my assertion, eventually one vendor actually checked with the factory and found that my finding was indeed true.
My point is that some of us indeed hear things that are VERY real, and VERY repeatable, even though they aren’t heard by everybody. Eventually people figure out how to measure and quantify those subtleties that we hear.
For your edification I’ve enclosed something I posted in an earlier thread some time ago regarding the human ear’s remarkable sensitivity.
Psychoacoustics is an inclusive term embracing the physical structure of the ear, the sound pathways, the perception of sound, and their interrelationships. Psychoacoustics, quite a recent term, is especially pertinent to this study because it emphasizes both structure and function of the human ear.
The stimulus sound wave striking the ear sets in motion mechanical movements that result in neuron discharges that find their way to the brain and create a sensation. Then comes the question, "How are these sounds recognized and interpreted?" In spite of vigorous research activities on all aspects of human hearing, our knowledge is still woefully incomplete.
Sensitivity of the ear
The delicate and sensitive nature of our hearing can be underscored dramatically by a little experiment. A bulky door of an anechoic chamber is slowly opened, revealing extremely thick walls, and three-foot wedges of glass fiber, points inward, lining all walls, ceiling, and what could be called the floor, except that you walk on an open steel grillwork.
A chair is brought in, and you sit down. This experiment takes time, and as a result of prior briefing, you lean back, patiently counting the glass fiber wedges to pass the time. It is very eerie in here. The sea of sound and noises of life and activity in which we are normally immersed and of which we are ordinarily scarcely conscious is now conspicuous by its absence.
The silence presses down on you in the tomblike silence, the first 10 minutes pass, then a half hour. New sounds are discovered, sounds that come from within your own body. First, the loud pounding of your heart, still recovering from the novelty of the situation. An hour goes by. The blood coursing through the vessels becomes audible. At last, if your ears are keen, your patience is rewarded by a strange hissing sound between the "ker-bumps" of the heart and the sloshing of blood. What is it? It is the sound of air particles pounding against your eardrums. The eardrum motion resulting from this hissing sound is unbelievably small-only 1/100 of a millionth of a centimeter or 1/10 the diameter of a hydrogen molecule!
Is this awesome or what?
The human ear cannot detect sounds softer than the rain of air particles on the eardrum. This is the threshold of hearing. There would be no reason to have ears more sensitive, because any lower-level sound would be drowned by the air-particle noise. This means that the ultimate sensitivity of our hearing just matches the softest sounds possible in an air medium.
Accident? Adaptation? Design?
That’s good science!!