Stereo

["samba -" <sambacomet@hotmail.com>]

  I don't think stereo is an artificial construct .We have  ears on either 
side of the head so we can do audio direction finding,which is similar to 
depth perception with binoccular vision.Notably animals tha are predators 
have binoccular vision ,to be able to accurately spring on prey,hawks cats 
while prey animals have 360 or close, and can move eyes independently to 
watch for attack,rabbits ,deer horses etc. (Possibly simians have 
binoccular 
for navigating in trees as some veggetarians have argued,but sqirrels 
don't 
and they are incredibly precise acrobats)  Anyway bilateral symmetry is 
one 
of the most outstanding qualities that identify life forms,though there 
are 
some assymetrical life forms,but not many , amoebas and slime molds come 
to 
mind. So the center line is a fundamental quality of orientation most 
animals also have a face ,which means front and rear orientation as 
well,so 
it would seem natural to mimic these qualities in audio formats.Owls have 
two ears but offset which apparentlyincreases their audio accuracy