If you ask an audiologist, they'll tell you most adult human
beings have hearing that rolls off somewhere between 16khz
and 20khz, and that as they get older, their hearing rolls off
even more.
If you ask an audiophile he'll tell you his CD's sound different
if you coat the edges with red magic marker, and that he can hear
the difference between different brands of speaker wire.
While you can't hear a signal at > 20khz, if one of sufficient
strength is mixed with an audible signal, subharmonics and phase
interference may produce audible artifacts. This is not the
same as hearing a 30khz tone.
There are two proposals to increase sampling rate & # bits per
sample in digital audio that have some merit, but neither is made
necessary by the need to transmit signals people can't hear.
Increasing the sample width from 16 to 18 or 20 bits has the effect
of increasing the resolution of very quiet passages. Increasing
the sample rate beyond 44khz allows you to construct simpler filters
to roll off the aliasing and other crap that creeps in over the
Nyquist limit.
Life is too short to waste on this sort of bullshit. Please stop this
discussion or move it somewhere else.
--
kent.williams@cadsi.com -- Can a filter sweep the noise floor?
How to program computers: Sit still. Stare at Screen. Type. Repeat.