Ok, so despite anecdotal evidence that some individuals can distinguish better-than-CD quality audio, we're questioning the existence of convincing double-blind studies. Yet we accept the varying cutoffs for what frequencies a person can consciously detect in isolation, as proof that we are incapable of perceiving audio information above those frequencies.

Are people asserting that an ear removed from a cadaver, hooked up to the best available scientific equipment, measures as a perfect biologically derived low pass filter? Or that we even partially understand how neurons work, when there may be quantum effects to be uncovered a century from now?

Intellectual history is a graveyard of models confused with reality.