I think that one impact that usually is not taken in to consideration in recreation of near field listening is that head shadowing is more noticeable for high frequencies and the longer time delay to the far ear as a longer path around the head needs to be traverse than for a plane wave coming from far away.
- Bo-Erik -----Original Message----- From: Sursound [mailto:[email protected]] On Behalf Of Stefan Schreiber Sent: den 3 december 2014 02:10 To: Surround Sound discussion group Subject: [Sursound] Iosono Proximity: A new and refreshing approach to code/represent audio distance cues? FYI... http://www.iosono-sound.com/game-audio/ http://www.iosono-sound.com/game-audio/proximity-technology/ > * Bring sound effects into the inner circle of the surround field > * Allows for highly accurate sound localization > > A standard PROXIMITY kit will consist of two intelligent, wireless > PROXIMITY loudspeakers and a PROXIMITY box, > * Connects to PC or console via standard HDMI > * Available from 8 December 2014 > > * Playback with PROXIMITY headphones or speakers > * Integration into the existing content creation tools > At the moment I can only try to guess how this (not yet available) technology might work: Are they creating distance perception via ICC cues? (see "Configuration and Installation" image. The added speakers are - very obviously - side speakers...) Further thoughts: If you would try to add distance cues to a "conventional" binaural system, you would certainly have to implement head-tracking, but also at least one set of "near-field HRTFs". (HRIRs change with distance. Our measured HRTF libraries are far-field. Opinions?!) I speculate that PROXIMITY headphones would code the distance cues in the same way as Iosono's (PROXIMITY) speaker system does. (So < maybe > via ICC cues, s. above.) As Iosono wants to be seen as a competent company, I don't believe that they will sell some snake oil. Especially since the market for Iosono PROXIMITY are serious gamers and not HiFi enthusiasts... :-D Best, Stefan P.S.: Bo-Erik etc.: I start to believe that the complete "standard" HRTF approach (binaural representation of surround sound via HRTF filters) might need a major overhaul. What would you need to deliver some (imaginary) perfect binaural system, which is supposed to reproduce all we can hear? (The question is valid, at least as a thought experiment.) You already have to measure "enough" HRIRs over the complete (3D) sphere, as usual. You would have to consider that possibly even small head movements vs. the torso might or will change the IR(s). (One additional degree of freedom) And if you want to include distance into the system (see above: < perfect > the system shall be, and nothing less...), you will add yet another degree of freedom. All the measured responses you already have in your library - considering head-torso changes - will fit to just (=only) one distance point. Accordingly, you would have to measure the complete HRTF sets at several distance points. (And even this "exploded" library might not be enough, I would argue. Starts to look all very depressing...) In the end, it really could be easier to < calculate > the HRTF sets than to < measure > (huge) HRTF sets. P.S. 2: I know that we have left standard binaural theories and/or practices. But I recently have had several discussions which seem < all > to indicate that our current HRTF models are far less complete or perfect than most people would assume. < Maybe this also indicates that we (currently) should apply BRIRs/BRTFs in surround/3DA --> binaural decoders, NOT (anechoic) HRTFs. Because BRIRs seem to deliver a more robust solution. Our "professional" colleagues from Smyth Research, IRT (BRS system) and Mpeg have recently all taken the BRIR route, an empirical fact which can't be ignored. > So: Why do BRIR-based binaural systems seem to work better than HRIR-based systems, even if HRIRs and not BRIRs should (theoretically) deliver the best solution? (A part of the answer has probably been given. Maybe our HRTF sets don't fit to real people, and people's real-world movements...) _______________________________________________ Sursound mailing list [email protected] https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here, edit account or options, view archives and so on. _______________________________________________ Sursound mailing list [email protected] https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here, edit account or options, view archives and so on.
