Re: perceptual segregation of sound

[Tania Xiao <txiao@xxxxxxxxxxxxx>]

Hi Mark,

I found your question extremely interesting as I have been thinking along a
similar strain recently. I am only a newbie postgrad student but based on my
limited experiences and music background, I believe that it is most probably a
combination of both. I find that when i was a novice musician, when i listened
to music (say a Bach Fugue) , it was all a bit of a "formless blob", however as
i learnt more and became more of an "expert", top down processes allowed me to
segregate and concurrently focus on multiple streams. In terms of your lion
example, as i am running away from the lions, i think  i would most probably
hear the two roars as one big loud alarm telling me to get away as far as
possible (i wouldn't really be concerned with which one the sound came out of).
However, top-down processes will allow me to realise that the sounds are coming
from two lions (perhaps based on the fact that in my "sound dictionary" the
roars are louder and a bit more complex compared to what i know about roars
coming from just one lion?). So, in a way, initially it is just one big sound
but then top down processes influence what i hear based on what i know and thus
allow me to "perceive" them as coming from two sources. Once again, this is just
my own thoughts on the matter but I am keen to hear what are your and others
thoughts about this?

cheers,
Tania


-- 
Tania Xiao BPsySc(Hons)
Research Assistant
Ph 3365 7193
School of Psychology and
Key Centre of Human Factors
University of Queensland
Brisbane 4072