Re: How many sources can humans perceive? / Number of co ncurrent (David Hirst )

Subject: Re: How many sources can humans perceive? / Number of co ncurrent
From:    David Hirst  <d.hirst(at)UNIMELB.EDU.AU>
Date:    Tue, 4 May 2004 10:46:53 +1000

Perhaps we need to think of 'degrees of streaming' and 'strategic processing'.

Take the example of an orchestra playing. There are many separate sound
sources but some are trying to play "in consort", eg. the 1st violins are
seeking to play in unison. In listening to the 1st violins it is hard to
separate the sound sources as they are forming a consolidated stream. If
one of the violins is out of tune then we find it easier to isolate it
since it has dropped out of the "consort stream". But what of the winds
etc? They may be playing their own "consort stream" but when taken together
with the strings they combine to form a "compound stream". At the level of
the musical work we may isolate it as a "complex stream" and we can
differentiate it from the traffic noises outside the concert hall and the
coughing inside the concert hall. So there are degrees of "streamyness".

So how might these degrees be operating? In many situations we are
listening for a purpose. We have a listening strategy that may be conscious
or sub-conscious. Strategic processing can shift the focus say from the
street sounds to the orchestra sounds to the trombonist in the back row
(visual strategies can reinforce aural ones or interfere if I can't see the
player I want to focus on.

I know you want to explore the extreme boundaries of the system, but the
problem is that the strategic processing considerations will get in the way
of any experimental design.


...my 2c's worth...

David



At 01:08 PM 3/05/2004 -0500, you wrote:
>I am interested in
>knowing how many concurrent but separate streams/sources people can handle
>in real time and what the depth of processing constraints may be.

David Hirst
Lecturer, Educational Design
Dept of Teaching, Learning and Research Support
University of Melbourne
Victoria, 3010
Australia
ph +61 3 8344 7568
Fax +61 3 8344 4341
http://www.infodiv.unimelb.edu.au/telars/cds/