On Wed, Nov 30, 2011 at 10:30:07AM -0800, Eric Carmichel wrote: > The post that said that Ambisonics resorts to some “psychoacoustic > trickery” was very well taken, and addresses one of my preliminary > concerns regarding first-order Ambisonics.
This is true, in the same sense as it is for e.g. stereo. But there's less room for error - 1st order is a delicate compromise and a well working system depends on everything being correct. Higher order is lot more 'robust'. At low F it reconstructs the original soundfield over a larger area, and for mid and high F almost all of the energy will be coming from the two or three speakers nearest to the intended source direction. These will have smaller angles between them as well (as there are more), so things will 'just work' even if speaker placement is not ideal etc. > ... But the background noise should be realistic in level, and > its wave field created by an Ambisonic arrangement (even first-order) > should hopefully be more realistic than the old-school method using > a single loudspeaker. I'm sure it will be. > ... Actually, I've never experienced a sense of “open space” when > listening to binaural recordings or simulations from HRTF IRs (including > the often-cited IRs made by Gardner et al at MIT during the 1990s). > I own ER-3A insert phones, Sennheiser HDA 200 audiometric headphones, > and my work-horse AKG K240 studio 'phones--but I've yet to hear a binaural > recording that replicates live sound--practically everything gives the usual > "in-the-head" effect or is lateralized (versus localized). Same here. Until head motion tracking is added - then things start to work quite well - for me at least. I remember a very convincing demo by Sacha Spors at T-Labs in Berlin. Your area of research seems a fascinating one. I wonder what would be the actual experience of someone using a CI after adaptation and training - it's probably difficult to communicate. I've heard of blind people being trained in using a camera + computer driven 'bed of nails' to transmit a crude picture using tactile stimuli. It seems (but I've not found any reliable reports), that after some time they are able to bypass the conscious interpretation of the tactice stimuli, and in a sense 'see' the picture. Would something similar occur for hearing if e.g. the input is only the equivalent of a six-band vocoder ? Ciao, -- FA _______________________________________________ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
