Why do intelligent people deny audio differences?


In my years of audiophilia I have crossed swords with my brother many times regarding that which is real, and not real, in terms of differeces heard and imagined.
He holds a Masters Degree in Education, self taught himself regarding computers, enough to become the MIS Director for a school system, and early in life actually self taught himself to arrange music, from existing compositions, yet he denys that any differece exists in the 'sound' of cables--to clarify, he denies that anyone can hear a difference in an ABX comparison.
Recently I mentioned that I was considering buying a new Lexicon, when a friend told me about the Exemplar, a tube modified Dennon CD player of the highest repute, video wise, which is arguably one of the finest sounding players around.
When I told him of this, here was his response:
"Happily I have never heard a CD player with "grainy sound" and, you know me, I would never buy anything that I felt might be potentially degraded by or at least made unnecessarily complex and unreliable by adding tubes."

Here is the rub, when cd players frist came out, I owned a store, and was a vinyl devotee, as that's all there was, and he saw digital as the panacea for great change; "It is perfect, it's simply a perfect transfer, ones and zero's there is no margin for error," or words to that effect.
When I heard the first digital, I was appalled by its sterility and what "I" call 'grainy' sound. Think of the difference in cd now versus circa 1984. He, as you can read above resists the notion that this is a possibility.
We are at constant loggerheads as to what is real and imagined, regarding audio, with him on the 'if it hasn't been measured, there's no difference', side of the equation.
Of course I exaggerate, but just the other day he said, and this is virtually a quote, "Amplifiers above about a thousand dollars don't have ANY qualitative sound differences." Of course at the time I had Halcro sitting in my living room and was properly offended and indignant.
Sibling rivalry? That is the obvious here, but this really 'rubs my rhubarb', as Jack Nicholson said in Batman.
Unless I am delusional, there are gargantual differences, good and bad, in audio gear. Yet he steadfastly sticks to his 'touch it, taste it, feel it' dogma.
Am I losing it or is he just hard headed, (more than me)?
What, other than, "I only buy it for myself," is the answer to people like this? (OR maybe US, me and you other audio sickies out there who spend thousands on minute differences?
Let's hear both sides, and let the mud slinging begin!
lrsky
Mrtennis,
"perceptible to some but not to others"?
This obviously denotes a level of superiority. More than this, I think, is the fact that some care about the differences but most don't. The fact that most don't care about the differences does not necessarily mean they can't perceive them.
Tubegroover...
"My question to you Larry is How do you two get along otherwise?:) There appears to be something deeper going on than your question..."
I was talking to a friend, who's also a shrink telling him about some of our interactions, like the time..
I had bought my wife a beautifully restored Classic Jag XK.
Drove it to Lexington to show it off--his first question,
"What kind of mileage does it get?"

The shrink burst out laughing...me, of course I was pissed.
He said, "Larry you don't see this as sibling rivalry, plain and simple?"
Guess I didn't, but his daily goal seems to be to 'light me up' about any and everything, this being one example.

Good call Tube...

Good listening,
Larry
I started in this 'hobby' some 40 yrs ago in college and early on I had a conversation that has shaped my thinking on the differences in the sound from a system. The conversation was with a roommate from a couple of yrs earlier and he told me how crazy he thought I was (some things never change) when I was pushing the loudness button, high or low filters, or adjusting the tone controls and he couldn't tell any difference. But he had bought a stereo in the meantime and then he started to actually listen. He finally got to the point where he could hear the difference those adjustments make.

I hear the difference cables make, don't really care if someone else doesn't and because of my old roommate, don't spend time trying to explain or justify it to someone that doesn't. Just real happy when I find somebody I can talk to about my 'hobby'.
All I say, is I think you are WAY over estimating the intelligence of this person. Just because someone has obtained a degree or has read a Windows operating systems book certainly does not equate nor qualify them as being intelligent. And certainly, with the given occupation of this person... As the public school systems in the US are a complete and total failure, to say the absolute least.
sense perception and intelligence, however its defined are independent of each other. the question shoule be rephrased to :

why do people deny audio differences ?

this question could also apply to other subjects.