Washline - Your run-on sentence there is incoherent. I did take a look at that link, and it seems to coincide with my point. Given that you can hear and differentiate "extension" beyond the 25khz of the esotar tweeter you must have some pretty amazing ears!
From the article you posted: "I haven't mentioned the most commonly touted marketing advantage of the new formats: their ability to capture sonic information higher than an audio CD's 22.05-kHz Nyquist-dictated cutoff. In reality, even the keenest-hearing children barely perceive audio information at 20 kHz, and, by middle age, even the sharpest ear can't hear anything higher than 15 kHz. Research data even suggests that the human auditory system lumps all frequencies higher than approximately 12.5 kHz into a single frequency "bin," in which humans cannot differentiate the various frequencies present."
From the article you posted: "I haven't mentioned the most commonly touted marketing advantage of the new formats: their ability to capture sonic information higher than an audio CD's 22.05-kHz Nyquist-dictated cutoff. In reality, even the keenest-hearing children barely perceive audio information at 20 kHz, and, by middle age, even the sharpest ear can't hear anything higher than 15 kHz. Research data even suggests that the human auditory system lumps all frequencies higher than approximately 12.5 kHz into a single frequency "bin," in which humans cannot differentiate the various frequencies present."