Re: human versus spectral resolution -- Gabor or Go Bare ?

[Pierre Divenyi <pdivenyi@xxxxxxxxx>]

Dick's and Alain's words of wisdom may need one point added. 

Yes, because humans often seem to outperform a Heisenberg/Gabor
theory-bound machine, it appears that we have two independent systems:
one to analyze spectrum and one to analyze time, neither of them worrying
much about what the other is doing. There are, however, some rules that
the two systems must abide by, in order to do their job so exceedingly
well: for frequency analysis to be accurate, the length of the time
window must be precisely known (i.e., the start and the end of the
observation interval); for time analysis the markers of the interval must
be of identical (or nearly identical) spectral composition. In other
words, to measure performance along one dimension, uncertainty along the
other must be minimal.

I am grateful to Bill Hartmann for pointing my nose to ch. 13 of his
"SSS" book, where he explains the uncertainty issue better than
I have seen it done anywhere else (on my modest level of physics and
mathematics). One thing, however, I want to point out is that studies in
agreement with the delta-f--delta-t tradeoff, as far as I can tell, have
used signals with dynamically changing spectra. That uncertainty of
bandwidth was paired with the temporal uncertainty introduced by gradual
onsets and/or offsets of the signal's temporal envelope (as Ronken [1971]
did),  thus producing conditions ideal for testing the uncertainty
theory's validity in psychoacoustics. The key word here is **dynamic** --
"bare" signals with firmly anchored temporal edges and spectra
that stand steady for the duration of the observation interval are likely
to produce results beating the theory's prediction.

Incidentally, a Gaborian tradeoff has been demonstrated between bandwidth
and the angular resolution of **moving** sources (Chandler and Grantham
[1992], JASA 91, 1624-36), as predicted by spatial extension of the
uncertainty theory (Divenyi and Zakarauskas [1992], in Auditory
physiology and perception, eds. Cazals, Demany & Horner, 563-70,
Pergamon, London). 

Pierre

At 07:21 AM 4/4/2008, Michael Fulton wrote:

Just a quick thanks to anyone who replied to my earlier question(s)
 
Mick
 

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