Grainger is right on the money here... Our ability to perceive music, like most of our abilities spans a huge range and pretty much follows a standard Gaussian distribution. I like to call it our MQ - or Musicality Quotient and just as a short list is made up of various abilities such as the ability to percieve rythm, tonality, pitch differential as well as other perceptive and cognitive parameters. Then there is the physiological aspects of individual ears, shape of ear canal, condition of cochlear sensing hairs, and a zillion other things, not even touching on the neurological issues, which also span a large range in humans.
Most people fall into the 3rd standard deviation, some of us are in the 5th and others in the 1st. Note this has nothing to do with musical enjoyment -- if you like what you hear, then nobody can question you on that, but it is totally absurd to tell somebody else what they can and can't hear, whether it be digital artifacts, differences in cables, dacs, speaker materials, etc. If somebody perceives those things then nobody has the right to call them snake oil or bullshit, etc., it just means that by luck of the draw and possiibly other influences over one's lifespan that their MQ is just higher and like intelligence quotient, they are working in a different zone. This stuff is not news to cognitive neuroscientists and can apply to every aspect of life that people perceive, it's not psuedoscience, it's hard science with a huge body of work to support it. I know people who cannot tell any difference between a car radio and a $100k system -- they simply cannot percieve the things that set them apart. Then there's another fact of life that some people are more visual, some more auditory, others more haptic, etc. and these things just represent a resultant vector of the various "Q"s. So yes, interestingly enough hearing and sound perception is not a uniform trait in human beings andd that all people have the same hearing abilities and the same perceptive and cognitive responses to those.
Also in my case as an adventitiously blinded person, it is also well known and documented that the previously active visual cortex is still plastic enough as an adult to be co-opted by the auditory processing system and why I may be more sensitive to these things than most people -- I simply have more processing power dedicated to auditory input as well as tthe converse, less dedicated to visual processing, which is normally 95 to 98% of our waking cognitive load. I didn't ask for this and I did nothing special to train myself, it's just the natural response of the brain and body to the loss of eyesight.
I will read John's article with great interest, as I did Gordon Rankin's but I'm certainly not going to engage in some of the ridiculous back and forth in the comments, especially those from people that have zero background in this stuff and are only parroting what they read on other forums by other armchair digital experts.
Bottom line is that everybody is right -- for them -- if they can't hear a difference between usb cables, then so be it, consider yourself lucky and stick with a $5 belken cable, but don't call it snake oil because there are people out here who can easily tell the differences between usb cables, as only one example.
-- Jim