Re: AUDITORY Digest - 28 Aug 2006 (#2006-194)

[Jont Allen <jontalle@xxxxxxxx>]

Xinhui
Look at Beranek's book on Acoustics for info on this problem. I think I 
saw something in there the other day when I was scaning it, about angles 
in tubes, and the effects.

Jont Allen

AUDITORY automatic digest system wrote:
> There are 2 messages totalling 185 lines in this issue.
>
> Topics of the day:
>
>   1. AUDITORY Digest - 18 Aug 2006 to 23 Aug 2006 (#2006-188)
>   2. Perceptual Weighting filter in AMR-WB (or AMR-WB+)
>
> ----------------------------------------------------------------------
>
> Date:    Mon, 28 Aug 2006 05:43:11 -0700
> From:    Abeer Alwan <abeera@xxxxxxxxxxxxx>
> Subject: Re: AUDITORY Digest - 18 Aug 2006 to 23 Aug 2006 (#2006-188)
>
> Mohan Sondhi 1986 JASA article (Apr. 79(4):1113-6) addresses
> this issue. It shows that for typical vocal tract dimensions, the
> bent causes a shift in resonant frequencies below 4 kHz in the
> range of 2-8%.
>
> Regards,
> Abeer
>
> >   1. A question on area function of vocal tract (2)
> >
> > ----------------------------------------------------------------------
> >
> > Date:    Wed, 23 Aug 2006 13:18:25 -0400
> > From:    xinhui zhou <zxinhui@xxxxxxxxxxxx>
> > Subject: A question on area function of vocal tract
> >
> > Dear List,
> >
> >   I am having a question about area function of vocal tract,
> >
> >   Area function is used to describe the vocal tract shape. It is
> > assumed that the bent shape of vocal tract can be regarded as a
> > straight tube with varying area along the axis,and only planar wave
> > propagation exists with limitation to certain frequency range.
> >
> >  I only undertand it intuitively .  Is there any book or paper which
> > formuates the idea of area function , i.e. why a bent 3D shape can be
> > simplied as a tube with area function?
> >
> >  Thanks in adavance,
> >
> > Xinhui
> >
> > ------------------------------
>
> ------------------------------
>
> Date:    Mon, 28 Aug 2006 22:03:12 +0800
> From:    #ARIJIT BISWAS# <arijit17@xxxxxxxxxxxxxxxx>
> Subject: Perceptual Weighting filter in AMR-WB (or AMR-WB+)
>
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> Dear Members of the List:
>
> =20
>
> I have a question regarding the "perceptual weighting filter" used in =
> the AMR-WB (also in the AMR-WB+) codec that is standardized in 3GPP and =
> ITU.=20
>
> =20
>
> Please check the 2002 Journal article from the developers of AMR-WB, =
> where they present the perceptual filter (pages 8-10, and Figures 3 and =
> 4).
>
> http://www.gel.usherbrooke.ca/audio/docs/IEEE2002_Bessette.pdf#search=3D%=
> 22perceptual%20weighting%20filter%20AMR%20WB%22=20
>
> =20
>
> Is this the best that one can achieve?=20
>
> I would like to know if there are any recent research efforts made to =
> improve this perceptual weighting filter to improve the quality of =
> wideband speech. If so, any pointers in that direction will be highly =
> appreciated.
>
> =20
>
> Thanks in advance.
>
> =20
>
> Best Regards,
>
> ~Arijit
>
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