This little theoretical tract would be to the point if all we were listening to were monophonic sine waves. Then the 20 kH hearing limit (probably even lower than that for most of us) would be indisputable. But lots of what the ear does is inconveniently non-linear.
I have been too naïve thinking that it could be better explained considering a simple sinusoidal wave. But we can dive deeper.
Over 100 years ago, the physicist Georg Ohm, the same who gave his name to Ohm's law, recognized the basic principle governing the function of the ear. He proposed that complex sounds are broken down into simple and discrete vibrations for subsequent analysis by the brain. In effect, Ohm suggested the ear performs a type of analysis described several years earlier by the french mathematician Jean Fourier. According to Fourier, even the most complex waveforms can be described by the sum of many simpler sine waves and cosine waves of appropriate phases and amplitudes. The results of modern research have confirmed Ohm's original idea that the auditory system performs a Fourier analysis of air-borne sounds by breaking them down into basis frequency components of different phases and amplitudes.
Also, we want to reproduce a stereo sound stage, and arrival times at left and right ear are an important cue. Tests have shown that the ear can differentiate very short differences in arrival time, and I have seen it suggested that recording at 192 kH is actually warrented to preserve these cues, even if we can't hear 96 kH sine waves.
Jeff
To localize the position of a sound source, the auditory cortex utilizes the cues of interaural differences in the time of sound arrival (a few tenths of a millisecond) and interaural differences in sound intensity
only, in spite of can have been suggested.
I think that the mechanism used by the ear to transform incoming sounds -the Fourier analysis- and the means by which complex sounds are received by the ear and interpreted by the brain are out of the scope of this forum.
Yours, Von (but not James Bond).