sadly we've been over all this a number of times(230+ pages of it just for this topic).
when the recording used mics that didn't roll off too much in the ultrasounds, when the instruments had loud ultrasonic content, when nothing in the studio emitted loud ultrasounds, when no DSP whatsoever downconverted or low passed the signal, when the sound engineers decided to keep high energy ultrasounds as is even though they probably know it might F up some devices, when our playback device is ok with that, when we bought the expensive highres version and it was the same master, when our headphone can actually handle the transient response and the distortions aren't just as loud or louder in the ultrasounds as the actual music, when our ears can notice all that stuff wile listening to actual music, when the moon is aligned with mars, then the sound is somehow objectively "richer" in content compared to redbook and maybe for a small minority of people it makes a small audible difference.
"takes a deep breath in french"
that how far I'm ready to go to keep an open mind about this. a possibility under ideal conditions for some people. if it was more than that, I assume we would have seen loads of sponsored studies demonstrating it by now. because it's been an eternal concern for audiophiles and because the industry has wet dreams about having clear proof of the audible superiority of highres and all the money they would make if they could advertised it without having to constantly play hide and seek with the law about the terms they use.
now mess with some parts of my requirement list and you can jump into no audible change at all, or into some changes that are actually making the highres file worst than the redbook one. so for all I know, several of the people saying there is a night and day difference are telling the truth about what they hear, but may be wrong about which is the best signal getting to their ears. how many people went to control that? if I count only with my fingers I expect it will be enough for headfi.
the other element is to find out if just upsampling the redbook version to avoid the 44khz filter of the DAC may or may not create an audible difference. if it does, then there is a need to check correctly that it's not all the difference heard with highres music. to make sure that we're paying for content and not for just a sampling number.
making claims about what we heard requires not only to demonstrate that we really heard things and not just "saw" them, but also the need to confirm the actual origin of the change before assuming that it's the highres content that made it all better. failure to provide all that is to me failure to demonstrate the hypothesis "music with it's original ultrasound content sounds better". and I'll then take the usual skeptical stand on the matter. not proved 100% impossibru, but certainly not proved to be true. and at this point I care about 2 things, how I feel for my music, and how blind tests in general answer to that question. personally I really don't care if something is highres or not and fail to identify anything in abx using the same format, suggesting that the ultrasonic content doesn't means shiit to me. I've had better luck upsampling redbook on some devices, so to me the low pass filter of the DAC is way more important than the ultrasonic content of the file. in general, most trials show guessing stats or super super close to it, even for the sponsored researches with an agenda to show ultrasounds are important.
until I see enough evidence of the contrary, I'll stick to that and let marketing talk to my hand.
off topic:
I do have a lot of biases against PRAT. I know that's really not "objective" of me, but I usually move on to something else anytime I see a review using that term. and I think to myself "the brain jury will disregard previous readings".
