It doesn't take a millionaire any longer. If you follow the rules of binaural psychoacoustics you don't need to measure any HRTFs to have a recording and loudspeaker reproduction system that delivers normal binaural hearing cues to any reasonable standard and does not make use of the stereophonic effect, or Ambisonic equations, but is a sort of home-friendly Wavefield Synthesis. Like WFS the listening area is much less restricted than that of a normal stereo system and since no HRTFs or head tracking is involved multiple listeners can be accommodated.
The first rule is that in any such chain, there must be one head shadow but only one and it need not be the end listener's. By head shadow in this rule we are just considering ITD and ILD in the frequency range where these affect localization. Since we nod, rotate, and lean and sound goes over, under, around the front, around the rear, etc. the ITD and ILD are quite smeared and so the brain is used to this and can adjust to an ITD, ILD head shadow not its own. So it does not matter how the ITD and ILD are recorded or synthesized as long as they are normal values for a frontal or rear stage object and then are delivered unaltered to the ear canals. So no personalized HRTFs so far or head tracking. The second rule operates in the higher frequency range where it is only the pinnae that determine localization. The rule is that in any recording and reproduction chain there must be one and only one set of pinnae and that set must be that of the end listener. Since few mic arrays have pinnae, including the Soundfield, there is seldom a problem of having two sets of pinnae in a system. (can use most dummy head mics without the outer ears.) So the only problem in having the remaining part of a soundfield binaural, is in making sure that all the sound sources come to the ear from a direction that is pinnae proper. So for example central solo frontal sound should come from the central front. All reflections or direct sound coming from the rear should have directional components not only for the pinnae, but also be delivered with binaural ILD and ITD values that are not then allowed to be altered by the listener's head dimensions. It turns out that in the horizontal plain it is not too difficult to provide what the pinnae need in directionality without making any HF HRTF measurements. So I and my converts easily obtain solid full circle localization of direct sound in the horizontal plane from ordinary 4.0 recordings like SACDs, DTS 5.1, SQ, UHJ, Dolby Atmos, Auro 3d, etc. using just four speakers and only a modest amount of numerical processing. Direct elevated sound sources can be accommodated using similar rules but that needs more research and real music recordings to test with. Hall ambience height is easily accommodated as is all concert hall reverb, also in a binaural friendly way. The rules are different for headphones or earphones, however. Lots of AES and other papers on all this, including several on the Ambiophone 3D mic array that anyone can copy and use to make better 4.0 recordings of live sound. -----Original Message----- From: Sursound [mailto:sursound-boun...@music.vt.edu] On Behalf Of Augustine Leudar Sent: Friday, November 03, 2017 3:17 PM To: Surround Sound discussion group Subject: Re: [Sursound] 3D Browser disco great sound design but no cigar on the binaural front - thats really not going to get solved until a quick and convenient way of measuring HRTFs is designed - I have several in case any millionaires out there are interested .... On 3 November 2017 at 18:36, Ralph Glasgal <glas...@ambiophonics.org> wrote: > Have you tried https://cloud.aria3d.com Using a Chrome browser, > Christos Tsakostas, a Greek audio researcher produces an up to 180 > degrees wide stage in the horizontal plane starting with ordinary 5.1 > or 2.0 recordings and you can play your own UHJ's this way. There is > also no reason why this technique could not soon produce a full circle > of direct sound using just four speakers from 4.0/5.1 media including > Ambisonic media decoded to 4.0 which I have heard this way via DTS media. > _______________________________________________ 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.
