Etienne said:
-----Original Message----- From: sursound-boun...@music.vt.edu [mailto:sursound-boun...@music.vt.edu] On Behalf Of etienne deleflie Sent: 31 May 2012 01:28 To: Surround Sound discussion group Subject: Re: [Sursound] Catching the same fly twice (and a curious question) >"....For example, the perception of how far away a fly is significantly >determined by what _other_ sounds exist at the same time. For example, a >fly always has low loudness. If one can hear a fly very clearly and the >environmental sound levels are high ... then something rings wrong. But it >is not just the relative loudness ... it is also the entire acoustic >ecology ... ecological consistency etc." I've previously thought of this as "perceptual contexts" that must model "causal contexts" - the background that must be there for the perception of any item or event to actually make sense. So, in vision, to understand the size and nearness of an object, you would have to have a visual array that has some detail about edges, texture (and texture gradient), occlusion and so on. Put simply, to perceive an item's location, you really mean: "location in this specific environment, in relation to landmarks (allocentric frame of reference) and me (egocentric frame of reference)" So, things aren't just "there", they are "nearer than-, further than- behind/in front/above-, coming, going, passing, accelerating, slowing, etc" - they are in an environment, not a Euclidean, abstract "space". For this reason, I sometimes refere to "place perception" as an alternative to "spatial perception" >"An other aspect of Gibson's ideas that are interesting concerns the >difference between mediated environments and non-mediated environments. >Gibson argues that it is impossible for a mediated environment to ever be >confused with a non-mediated environment... no matter how good the >technology. The reasons are environmental again. Ofcourse, that doesn't >mean that there cant be a 'suspension of disbelief' ... but some argue that >the suspension of disbelief is the domain of art, not science. It is the >expression (of the art) that fools the perception (not the stimuli)." However, I have found that a mixed mediated+ -non-mediated environment can contain significant local confusions. Years ago at York, I used an SF mic to record Dylan Menzies idly playing the piano, in a room equipped with a periphonic playback system. When I played it back, he then took to accompanying his own earlier playing. When he did so, the distinction between mediated and non- mediated instantly blurred. When he stopped the accompaniment, the recorded nature of the mediated environment became obvious. > Here is where I find 'fault' or room for improvement with a lot of > controlled laboratory experiments: >this has been argued by a few researchers. Personally, I am starting to >question that the centrality of 'direction', not just evident in audio >synthesis interfaces but also evident in the underlying theory of >ambisonics (and in Gerzon's ideas), is not actually just a direct result of >the limitations of a laboratory based scientific understanding of sound >perception. I wonder if perhaps direction is *not* that important to >spatial audio. Ofcourse, it is a part, but is it central? This view leads >to the questioning of the value of higher order ambisonics. I think of this as the "direction is space fallacy" - if we think of what spatial perception is and does, the directional localisation of static sources, especially by static perceivers, is very much the minority. Distance (I.e distance from me, the perceiver = range), change of range (most especially, coming toward me, passing me(Doppler) and heading away from me) are much more interesting than direction. Indeed, direction is simply a component of location and movement. Peter Lennox _____________________________________________________________________ The University of Derby has a published policy regarding email and reserves the right to monitor email traffic. If you believe this email was sent to you in error, please notify the sender and delete this email. Please direct any concerns to info...@derby.ac.uk. _______________________________________________ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
