> The main mechanisms for disambiguating 'cones of confusion' (and this includes front-back reversals) are: pinnae effects (Batteau) and head-movements (Wallach) - so, without either of these mechanisms at play, one would expect directional ambiguity.
You can test the relative importance of these for YOURSELF with the famous Malham / Van-Gogh Experiment http://www.ambisonia.com/Members/ricardo/PermAmbi.htm/#VanGogh. I still have some Diamond encrusted caps with optional Golden Pinnae but you need to pay in used bank notes. No Confederate money please. Michael came up with his rE & rV theories ... not by considering how to best replicate HRTFs bla bla .. but by asking ... "what information could the Mk1 Human Head (+ torso + processing inside + bla bla) possibly have available to determine localisation?" If youi perform the above experiment, you'll find the Moving Head cues are FAR more important than the Fixed Head cues (HRTFs bla bla). Where the HRTFs have the most significance is in the vertical plane. It's the different frequency response as a source moves off the horizontal plane that allows the Mk1 HH to process 'height'. But even then, Moving Head cues are far more unambiguous .. and don't require a priori knowledge of the source. If the HRTF cues break down completely (eg simulating a pair of coincident back to back cardioids as the crudest possible binaural decode), simulating the Moving Head cues (head tracking) lets the Mk1 HH decode all this without any problem, fuss or discomfort. > I would like a little more information on ?head movements?. I suspect all head movements are being treated as equal, and I have a theory that short rapid movements (like shaking the head) should be treated separately from movements that include the shoulders, or even the whole body. Short rapid movements of the eyeball have been studied and are well understood; without these small movements the visual field collapses completely. Does something similar happen for the aural field ? One of the more surprising things that Michael worked out is that the Moving Head localisation models gave the "same answers" regardless of whether they assumed you turned your whole body to face the source (eg Makita) .. or those that only allowed small involuntary head movements (eg Clark, Dutton & Vanderlyn IIRC) It's all there in his "General Metatheory .... " if you are prepared to study it and follow up the references. See especially the 'stereo' appendix. http://www.aes.org/e-lib/browse.cfm?elib=6827 _______________________________________________ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here, edit account or options, view archives and so on.
