--- I don't agree with you on this Dac, it doesn't matter if your ears are different, bigger, smaller, etc... every person with a normal hearing range (20hz to 20khz) can detect the same variations in decibels, pitch, etc (the only factor that affects that is age)...
anyone with normal hearing will receive the same information, no matter how your ear is shaped... for example, while passing through the pinna (visible part of the ear that resides outside of the head), sound goes through a filtering process in which sounds in the frequency range where human speech is normally found are enhanced. Finally, the filtering process also adds directional information to the sound. This happens regardless of how your ear looks, the psychoacoustics only change from person to person in how their brain processes the information... thats where ear training, musical training, etc, comes in...
--- That's it, training and practice is what makes the difference... in everything! just like you said about hitting a moving target at 50 yards, only the best shooters will have a chance, but that is not because their eyes or their trigger fingers are different than others, just that they have been practicing their shooting skills for longer, no?... but then you kind of contradicted yourself... just saying for the sake of keeping this discussion going
much respect. PS