Re: [linux-audio-user] 192kHz

On Thu, 26 Jan 2006 16:11:48 -0500
Gene Heskett <gene.heskett@email-addr-hidden> wrote:

> On Thursday 26 January 2006 15:36, Wolfgang Woehl wrote:
> >Ismael Valladolid Torres <ivalladt@email-addr-hidden>:
> >> I don't see any reason to work at 192KHz. Apart from huge
> >> files, Nyquist is on my side.
> >
> >Wouldn't interference of 2 or more signals from above the
> >audible band have the potential to produce energy within the
> >audible band?
> >
> If there is something non-linear in the mixing process, yes.
>
> >Wolfgang

A fact often forgotten is that the human ear is itself non-linear in
response. It can be reasonably argued that (assuming no other
distorting factors exist) well out of band signals could interfere
'mechanically' inside the ear and produce audible difference signals.
What is more, these signals will vary from person to person.

An experiment I have tried that seems to show some non-linear
behaviour, and gives different results for different people is to
produce an apparent pitch change to a constant frequency tone.

Play a 440 Hz sine wave (A) to someone at very low amplitude. Let them
get comfortable then suddenly increase the level about 40dB. Some
will say the pitch dropped, a few that it rose and some that there was
no change.

It seems to work best if you can get the amplitude change to take place
at the zero crossing point so there is no audible click.

-- 
F