> > Head width were certainly affect ITDs, but to what extent does this alter > our sense of sound-source direction? Relatively gross errors seem to have > minimal affect on lateralization, but this is different from localization > in 3D. Pinna size and shape alter the spectral nature (name phase / > amplitude) of higher-frequency, broadband sounds, but we can "re-learn" > localization ability with a new or different set of ears. Head movement is > certainly a way of resolving ambiguities
I think head movements do much more than just help in the perception of discrete spatial attributes, such as sound onset direction. I think they also contribute by helping our perceptual faculties 'accept' that the information being presented is correct and reliable. I'm not sure what the right terminology would be to express this ... maybe one could say that head movements support the suspension of disbelief, or maybe one could say that head movements help the perceptual faculties choose the *right* information to perceive. One of the characteristics in Gibson's ecological approach that has been adopted by the VR field is the idea that perceptions are confirmed as true through 'successful action in the environment'. Tilting one's head can be considered action in the environment, and if the spatiality of the sounds heard correlate then that action can be considered successful. So head movements help to confirm that what is being perceived is correct. Perhaps a way to describe it is to say that head movements don't just support quantitative aspects of perception (eg. "this sound is 45deg +- 5 deg on the right) but also qualitative aspects: "it sounds real" which leads to "it must be right". I read in Handel's text "Listening" (I haven't looked for more substantive references) that our perceptual systems are more limited by their ability to *choose* the right information than by their ability to *pick up* information. I think the tracking of head-movements on headphone listening systems helps listeners choose the right information, which contributes to but is significantly different from just helping resolve ambiguities. > With the eyes closed and subject under constant rotational velocity (i.e., > vestibular system in equilibrium or, equivalently, turned off), stationary > sounds sources appear to move and moving sound sources appear to be > stationary. this could be understood in similar terms ... perhaps both the visual field and the balance system help to confirm that certain information perceived is the *right* information. I guess one question to ask here is: do the visual field and vestibular system *add* extra information... or do they just help the auditory system to choose the right information? Perhaps one indication would be if the listener's perceptions remain correct after they have re-closed their eyes. (ie. perhaps the 'learning' actually exists as 'being able to choose the right info to perceive') Etienne > I won't say more at this time because I don't want to pass along info > without having permission to do so. I'll have a chance to visit Bill's lab > in the very near future, and ask when the results of the study are slated > for publication. > > Best, > Eric C. > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > https://mail.music.vt.edu/mailman/private/sursound/attachments/20130330/5b4ffa7e/attachment.html > > > _______________________________________________ > Sursound mailing list > Sursound@music.vt.edu > https://mail.music.vt.edu/mailman/listinfo/sursound > -- http://etiennedeleflie.net -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://mail.music.vt.edu/mailman/private/sursound/attachments/20130402/bfa27050/attachment.html> _______________________________________________ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
