26 Jan
2004
26 Jan
'04
7:31 a.m.
On Mon, Jan 26, 2004 at 11:54:26 +0100, Joern Nettingsmeier wrote:
Which membrane? The basilar membrane is responsible for frequency alaysis
(AFAIR), but its limited by its geometry. Doesn't it detect resonances in
the narrowing tube? Transients could be detected before the pressure wave
reaches the basilar membrane, though I'm just guessing here.
This is not
quite correct. While humans can not hear continuous tones over
20-odd kHz that is not the whole story, the frequency reproduction also
limits the minimum transient rise time, which is detected by a different
part of the ear (IIRC, IANABiologist and my psychoacoustics textbook is at
work).
interesting point. but isn't membrane inertia the limiting factor in
transient reproduction anyway? my naive understanding is that min rise time = nyquist
freq. if we
cannot perceive frequencies above, say, 20k, all we win by faster
sampling is more accurate timing information.
but there is a worst-case "timing error" of 1/24000 sec, which does not
seem much to me...
Its not the timing error - it wont be quatised to the nearest sample
AFAIK, but you will get substantial ripple from the reconstruction filters
fi you try to reproduce transients near nyquist- dunno how that is perceived.
i'd like to read more, but i haven't been able
to google anything up
about transient perception and reproduction. any pointers?
There seems to be some relevent stuff here:
http://arjournals.annualreviews.org/doi/full/10.1146/annurev.neuro.23.1.285
but its a bit over my head.
for the record, here's a 1998 aes paper that
elaborates on the
consequences of higher sampling on filter artifaces in the audible
range: http://www.nanophon.com/audio/antialia.pdf
Thanks, thats interesting.
- Steve