[AG-TECH] Sound localisation work?

[Brian Corrie]

Hello all,

There is a group at the Australian National University/CSIRO in Canberra,
Australia that is doing work on spatialized sound (not in an AG/conferencing
context though). Markus Buchhorn [Markus.Buchhorn at anu.edu.au] is at ANU and
is also on this list. He might be able to help... The main person doing
spatialized audio in this group is Stephen.Barrass at cmis.csiro.au. I am not
sure what they are working on now... See
http://www.cmis.csiro.au/imvs/index.htm for more info...

Cheers,

	Brian

> -----Original Message-----
> From: Osland, CD (Chris) [mailto:C.D.Osland at rl.ac.uk]
> Sent: Thursday, November 28, 2002 5:32 AM
> To: AG Technical Developers
> Subject: RE: [AG-TECH] Sound localisation work?
> 
> 
> It was a subject I attacked during a short sabbatical in Germany
> a few years ago for a thing called the Communication Wall - a VR
> + video keying approach to the same sort of problem as the AG
> aims to tackle.
> 
> One of the problems that dogged that project was that as they were
> using hard surfaces for the rooms (they used rear-projected stereo
> projectors) there was a disastrous amount of secondary reflections
> of any sound source.  I draped carpet over the side walls (not used
> for projection, but they happened to be plasterboard and so hard)
> and improved things a lot.
> 
> There are many problems to solve in the AG context:
> 
> 1.	non-unique views of participants:
> 
> If a person is visible in more than one view, where should the
> virtual sound source corresponding to that person be positioned?
> 
> 2.	multiple people viewing/hearing at each site
> 
> There is basically no known solution to the problem of how to
> create a sound field that is the same for several people, unless
> you put headphones on each person AND headtrack them.  The problem
> can be partially solved by using phase differences more than
> amplitude differences (this is done by the TiMax system used in
> theatres) but the normal layout of an AG node makes this difficult
> to achieve - the physical distances are too small.
> 
> 3.	the rooms have to be excellent acoustically before you start
> 
> This is really the same point as I made above concerning reflective
> walls - if there are uncontrolled reflections, any effort put
> into generating localized sound is wasted.
> 
> I created a website about my project and will try to get that
> up somewhere - I think it's fallen off the edge of our web
> for the present.
> 
> I'll try to find references to things like
> 
> 	TiMax - the theatre system - they were at
> 
> Robin Whittaker
> Out Board Electronics Ltd
> www.outboard.co.uk
> T: +44 (0)1223 837827
> F: +44 (0)1223 837798
> 
> 			but went into receivership some months ago;
> 			I think Robin has hooked up with another firm
> 			to try to keep TiMax going
> 
> 	Crystal River - people who make sound localization cards for PCs
> 
> and the places where I found out stuff for my sabbatical.  It looks
> as though Crystal River have gone belly up as well.
> 
> 	A couple of useful links are
> 
> 	http://www.dform.com/inquiry/spataudio.html
> and	http://www.anu.edu.au/ITA/ACAT/Ambisonic/Spatiallinks.html
> 
> Enjoy
> 
> Chris
> 
> ____________________________________________________________________
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> 
> 
> -----Original Message-----
> From: Michael Daw [mailto:mike.daw at man.ac.uk]
> Sent: 28 November 2002 12:52
> To: AG Technical Developers
> Subject: [AG-TECH] Sound localisation work?
> 
> 
> I'm just wondering if anyone knows of any work going on to do 
> with sound
> localisation in the AG? I'm thinking particularly of 
> development to help
> locate where peoples' images are on the screen and in holding 
> simultaneous
> conversations between sites, or anything related.
> 
> I'd be grateful if someone could provide contacts (if any).
> 
> --Mike
> 
> _______________________________________________________
> 
> Michael Daw
> SVE Group (Supercomputing, Visualization and e-Science)
> 
> Manchester Computing, Kilburn Building,
> University of Manchester, Manchester M13 9PL, UK
> 
> Tel: +44 (0)161 275 7026
> Fax: +44 (0)161 275 6800
> Email: michael.daw at man.ac.uk
> 
> http://www.sve.man.ac.uk/General/Staff/daw
> _______________________________________________________
>