I came across a thread on another forum which put forth the premise that all of our senses can be deficient in ways we do not yet fully understand. The main argument for this premise was the number of color blind people who have otherwise normal vision. Among those "color blind" individuals there are those who can be divided into subgroups of various shades of color they cannot perceive and various degrees of color blindness to specific colors. One individual who is red/green color blind may have somewhat better perception of intense hues while other individuals might be totally red/green color blind seeing only shades of grey no matter the intensity of the color presented. Another person can see red/green without problem but is blind to blue/yellow hues. The rare instance would be complete color blindness where everything becomes a black and white movie. Yet all of those afflicted with various degrees and types of color blindness could have "20/20" vision when measured for a more basic perceptive ability.
I know individuals who have a poor sense of smell and those who can detect specific fragrances with ease. The perfume industries select such highly prized individuals as testers for their products. The food and wine industries select those who can pick out the various flavors in a product being prepared for sale. In Italy no Balsamic vinegar, proscuitto, Parmeggiano Regianno or a hundred other specialities can be labelled as DOCC until they have passed a board of expert tasters. I have many friends who can detect small bits of herbs and spices while others haven't a clue what's in a dish.
According to JA an upcoming article in Stereophile will discuss studies which lump us into "diminishers" and "exagerators". That would suggest we all have some ability, whether innate or chosen, which predicts how our senses will pick up on various stimuli. Apparently some of us are simply "better equipped" to use one or more of our senses when we compare our perceptions to those of another individual.
Some of us have perfect pitch and some can easily hear the way a chord progression moves or the timing of a performance is more expressive to some than to others. Musicians speak of another player's "ear" for certain qualities.
Is this then an explanation for why some individuals are better able to hear the effects of cables, AC conditioners, various alternative room treatments, etc? Shouldn't we expect all of our senses to have more or less the same peculiarities and some of us would then be better able to percieve small changes in sound just as the prized sommelier can detect small changes in flavor? If one individual can be color blind but not blind, couldn't another individual be deaf to specific qualites of sound while not being completely deaf?