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Re: Group delay variations

At 02:30 PM 6/29/00 -0400, Jont Allen wrote:
> Jont,
> Then please explain a little more clearly what you meant by this:
>       " I would (and have done so in the past actually) measure the
group delay.
>         This does a nice job of characterizing the phase in a
meaningful way, and
>         avoids the problem of flat delay that does not really effect
>         If the group delay variations, either between the two ears, or
>         frequency in one ear, are too large, then you will hear that

This does not say that the threshold delay variations for the two cases
the two ears or across frequency in one ear) is the same. It just says
that there
is a threshold for each case. These two thresholds are not the same. The first
is order 10s of microseconds. The second is 10s of milliseconds. Thus there is
about a factor of 1000 difference between the two cases. Please dont pick
on the accuracy of my numbers here. I am speaking in rough terms.


My exuberant expression of interest in the group delay variation vs.
bandwidth issue was only motivated because you, Jont, brought up the group
delay issue and Roy Patterson tied it into bandwidth. The actual figures
are irrelevant for my argument: I just wanted to point out that the group
delay/bandwidth trade-off appears to exist in both the monaural and the
localization systems.

I hope this clears up at least one of the definition issues.

All the best,


Pierre Divenyi, Ph.D.      Experimental Audiology Research (151)
                                     V.A. Medical Center, Martinez, CA
94553, USA
Phone: (925) 370-6745
Fax:     (925) 228-5738
E-mail :                       pdivenyi@marva4.ebire.org