Dear All, Here are some references:
Brungart and Rabinowitz [1] showed that HRTF vary significantly for sources in the proximity region (i.e. at distances less than 1m from the head). Lentz et al. [2] perceptually evaluated measured HRTFs at different distances from the head, showing limits of noticeable differences between near-field and far-field HRTFs. Romblom and Cook [3] proposed near-field compensation filters. Duraiswami et al. [4], Zhang et al. [5], and Pollow et al. [6] compute HRTFs for arbitrary field points using spherical harmonics decomposition (as an extension of the work of Evans et al. [7]). Duda and Martens [8] evaluated simulation results on a spherical head model Have fun reading! Very best, Markus [1] D.S.Brungart,W.M.Rabinowitz:Auditorylocalizationof nearby sources. head-related transfer functions. J. Acoust. Soc. Am. 106 (1999) 1465–1479. [2] T. Lentz, I. Assenmacher, M. Vorländer, T. Kuhlen: Precise near-to-head acoustics with binaural synthesis. Journal of Virtual Reality and Broadcasting 3 (2006). [3] D. Romblom, B. Cook: Near-field compensation for hrtf processing. 125th Conv. Audio Eng. Soc., San Francisco, USA, 2008, no. 7611. [4 ]R. Duraiswami, D. N. Zotkin, N. A. Gumerov: Interpola- tion and range extrapolation of HRTFs. IEEE ICASSP, Montreal, Canada, 2004, 45–48. [5] W. Zhang, T. D. Abhayapala, R. A. Kennedy, R. Du- raiswami: Modal expansion of HRTFs: Continuous repre- sentation in frequency-range-angle. ICASSP, Los Alami- tos, USA: IEEE Computer Society, 2009, 285–288. [6] Pollow, M., Nguyen, K.-V., Warusfel, O., Carpentier, T., Müller-Trapet, M., Vorländer, M., and Noisternig, M. (2012). “Calculation of Head-Related Transfer Functions for Arbitrary Field Points Using Spherical Harmonics Decomposition,” Acta Acust United Ac, 98, 72–82. doi:10.3813/AAA.918493 [7] M. J. Evans, J. A. S. Angus, A. I. Tew: Analyzing head- related transfer function measurements using surface spher- ical harmonics. J. Acoust. Soc. Am. 104 (1998) 2400– 2411 [8] R. O. Duda, W. L. Martens: Range dependence of the re- sponse of a spherical head model. J. Acoust. Soc. Am. 104 (1998) 3048–3058. > On 24 Jan 2018, at 15:01, John Merchant <john.merch...@mtsu.edu> wrote: > > Tom Smurdon and Peter Stirling of Oculus presented research on near-field > HRTF for VR at last fall's OC4. The video of that talk is available here: > https://www.youtube.com/watch?v=l7mhXRB9PA4 > > ________________________________________ > From: Sursound <sursound-boun...@music.vt.edu> on behalf of > st...@mail.telepac.pt <st...@mail.telepac.pt> > Sent: Tuesday, January 23, 2018 8:12 PM > To: Surround Sound discussion group > Subject: Re: [Sursound] A submittal for a patent on Ambisonics? > > Citando Augustine Leudar <augustineleu...@gmail.com>: > >> Hi Jack, >> >> Aside from ILDs, ITDs, I also wondered if the pinna was able to distinguish >> >> very close sound sources due to the fact the wavefront would be much more >> >> curved almost spherical to the degree that it would be different pressure >> >> present at different folds of the pinna (ie very close up sound slike a >> >> mosquito) . I dont think theres been much done on that... > > Hi Augustine, > > I think "there has been done quite a lot on that"... 😉 > > (Reproduction of near-field audio sources) > > Beside of spherical waves (and their consequences) we should not > overlook that any high-frequency emitting (annoying) mosquito next to > your left ear would be heard much softer at your right ear, the head > shadow being even more relevant at close distances. > > BR > > Stefan > > P.S.: It is important to know about the "depth" of a mosquito audio > object relative to your head, both in VR and in real life... > >> On 23 January 2018 at 11:58, jack reynolds <jackreynolds...@gmail.com> >> >> wrote: >> >>> It looks like a method for binaural rendering with multiple distance HRTFs. >>> >>> >>> >>> Ambisonics could be one of the inputs, but it seems to be aimed more at >>> >>> object based virtual reality, where the listener is more likely to come >>> >>> very close to an audio source. >>> >>> >>> >>> Most HRTFs are currently measured at 1m distance, so any objects closer >>> >>> than 1m are not currently rendered correctly. >>> >>> >>> >>> Far field HRTFs are closer to plane waves, whereas close up audio objects >>> >>> emit more spherical waves, creating greater differences in interaural time >>> >>> difference (ITD). >>> >>> >>> >>> Jack >>> >>> >>> >>> On 23 January 2018 at 11:18, Bearcat Şándor <bearcatsan...@gmail.com> >>> >>> wrote: >>> >>> >>> >>> I don't know a lot about patent law, but is this an attempt to tie up our >>> >>> beloved Ambisonics? >>> >>> >>> >>> http://www.freepatentsonline.com/y2017/0366912.html >>> >>> >>> >>> .... > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > <https://mail.music.vt.edu/mailman/private/sursound/attachments/20180124/16ff3135/attachment.html> > _______________________________________________ > 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. > _______________________________________________ > 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. _______________________________________________ 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.
