Digital BW, The Print

>It is considered conventional wisdom that the ear cannot hear frequencies
>above and below a certain point, but that the existence of sound in those
>frequencies has an audible effect on what we can. Two examples are called
>intermodulation and harmonics.

Harmonics is a different thing, and has nothing to do with the ability for
signals beyond your hearing range to "effect" the signals within your
hearing range.  Harmonics are merely integral multiples of a given
frequency.  Intermodulation distortion is probably a better way to
characterize it.

>When cds first came out, a mental institution noticed that
> digital music did
>not relax the patients anymore and they had to restore an all
> analog system.
>(this was reported in the Syd-Aud-Con journal which is
> distributed to audio
>and electro-acoustic engineers.)

I don't believe any conclusion can be drawn by that.  When CDs first came
out, they did not use oversampling to smooth out the output signal, and that
is why they sounded "digital", and in fact, sounded annoying to people who
weren't mental patients as well.  This issue has long been attended to by
the use of oversampling and first order filters.  Prior to using
oversampling, third order filters were primarily used, and these induced
phase shift in the output, simply because different frequencies take
different times to travel through the filter.  The result is typically
annoying to human hearing.  Not so with first order filters.

Austin