Re: [Sursound] Upcoming Android apps ambisonic related
On 21/12/2013 03:40, David Worrall wrote: I remember reading that, with exposure, human's audio-processing hardware can adapt to/learn how to use a non-optimal HRTF, given a bit of time. Does anyone have a reference for this? http://128.102.119.100/publications/wenzel_1993_Localization_Head_Related.pdf David On 15/12/2013, at 5:57 PM, Marc Lavallée wrote: Hi Dave. I never tried head tracking while listening to stereo or Ambisonics (I'm not that much of an insider). I'm optimistic about it, even with virtual microphones; but I suspect that the contribution of head tracking would then be limited to the interpretation of level differences and transitions between the left and right. What I miss is a realistic HRTF rendering experience (without head tracking). For every HRTF I tried (from the KEMAR and LISTEN sets), as with stereo, front sources were always in the head, not at the front; the front test tone was just louder then the rear one. I don't know what are the right conditions to experience good HRTF based localization (in a acousmatic context, without visual cues). I don't know if using a personal (measured) HRTF would be better; I just assume that it would be better because my own binaural recordings sound quite right, but probably just for me (to be verified) because I experienced the real sound scenes while recording them. -- Marc Sun, 15 Dec 2013 13:50:09 +, Dave Malham dave.mal...@york.ac.uk a écrit : Hi Marc, I think it is, perhaps, a little pessimistic to talk of needing to assess dozens of hrtf's to find the one that's right for for you, if you have head tracking in use. My experience with this dates back 20 years to the days of the Lake DSP Huron systems when I first heard this - even without specific hrtfs switching the the head tracking on was enough to change the system from not working (for me) to working. The head tracking (done with a Polyhemus sensor controlling the processing of FOA B format signals prior to decoding) was enough with no need to select hrtf's. I would suspect that having just a few to select from would be enough. Dave ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound __ Prof. Dr. David Worrall Emerging Audio Research (EAR) Audio Department International Audio Laboratories Erlangen Fraunhofer-Institut für Integrierte Schaltungen IIS Am Wolfsmantel 33 91058 Erlangen Telefon +49 (0) 91 31 / 7 76-62 77 Fax +49 (0) 91 31 / 7 76-20 99 E-Mail: david.worr...@iis.fraunhofer.de Internet: www.iis.fraunhofer.de Senior Adjunct Research Fellow, Australian National University. david.worr...@anu.edu.au -- next part -- An HTML attachment was scrubbed... URL: https://mail.music.vt.edu/mailman/private/sursound/attachments/20131221/90a012e3/attachment.html ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
dw wrote: On 12/12/2013 12:40, Marc Lavallée wrote: Hi Étienne. etienne deleflie edelef...@gmail.com a écrit : ... and then ambisonics is suddenly available to masses of people, for very cheap, and with a consistent and quality spatial experience (assuming the HRTF decoding can be done right). Etienne HRTF decoding is the problem here. Finding a proper HRTF profile by trying many (over of hundred) is not a solution; realistic binaural reproduction works only when I listen to my own binaural recordings. So, to enjoy mass produced ambisonics, I'd need personalized HRTF measurements, a service that is not cheap and non-existent for a majority of HRTF challenged people; for us, decoding ambisonics over 4 speakers is a better option, It is undeniable that listening to FOA over a bunch of speakers will mess up your 'personallised (actual) HRTFs' considerably.. ??? Frankly, this is a messed up statement. You need HRTFs if listening via headphones. Just for clarification. (Nobody corrected this.) The undeniable tag doesn't help a lot, BTW. Best, Stefan Schreiber ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
On 12/21/2013 04:40 AM, David Worrall wrote: I remember reading that, with exposure, human's audio-processing hardware can adapt to/learn how to use a non-optimal HRTF, given a bit of time. Does anyone have a reference for this? purely anecdotal, but i was surprised (and just a little bit shocked) to find i'd learned david griesinger's ear-canal-RTFs within five minutes of listening over his compensated headphones, for my first-ever externalized binaural image experience. google for griesinger's presentations and papers on ear-canal probes and headphones calibration. there is one in particular i have in mind, sickly green background, which is awesome (but for the choice of color), but i don't have the link atm. i guess it's listed on his homepage. you should find something of interest to your question in the references. -- Jörn Nettingsmeier Lortzingstr. 11, 45128 Essen, Tel. +49 177 7937487 Meister für Veranstaltungstechnik (Bühne/Studio) Tonmeister VDT http://stackingdwarves.net ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
On 21/12/2013 10:58, Stefan Schreiber wrote: dw wrote: On 12/12/2013 12:40, Marc Lavallée wrote: Hi Étienne. etienne deleflie edelef...@gmail.com a écrit : ... and then ambisonics is suddenly available to masses of people, for very cheap, and with a consistent and quality spatial experience (assuming the HRTF decoding can be done right). Etienne HRTF decoding is the problem here. Finding a proper HRTF profile by trying many (over of hundred) is not a solution; realistic binaural reproduction works only when I listen to my own binaural recordings. So, to enjoy mass produced ambisonics, I'd need personalized HRTF measurements, a service that is not cheap and non-existent for a majority of HRTF challenged people; for us, decoding ambisonics over 4 speakers is a better option, It is undeniable that listening to FOA over a bunch of speakers will mess up your 'personallised (actual) HRTFs' considerably.. ??? Frankly, this is a messed up statement. You need HRTFs if listening via headphones. When listening over speakers decoding ambisonics over 4 speakers is a better option, , you are listening via the the superposition of several of your natural HRTFs with varying amplitudes and delays. In the time domain this is not equivalent your HRIR for any real source. Interpolation between these several speaker-head IRs will occur at the sweet spot to give more or less correct ILD and ITD values, but outside of the sweet spot, and at high frequencies, the resulting IR is alien. Just for clarification. (Nobody corrected this.) The undeniable tag doesn't help a lot, BTW. Superposition of IRs is a fact of life. Best, Stefan Schreiber ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
On 21/12/2013 10:58, Stefan Schreiber wrote: Just for clarification. (Nobody corrected this.) The Ambisonic scientologists don't want to play? In 1901, Allen Upward http://en.wikipedia.org/wiki/Allen_Upward coined /Scientology/ as a disparaging term, to indicate a blind, unthinking acceptance of scientific doctrine http://en.wikipedia.org/wiki/Scientology The undeniable tag doesn't help a lot, BTW. Thanks for that. -- next part -- An HTML attachment was scrubbed... URL: https://mail.music.vt.edu/mailman/private/sursound/attachments/20131221/c641a3d0/attachment.html ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
dw wrote: On 21/12/2013 10:58, Stefan Schreiber wrote: dw wrote: On 12/12/2013 12:40, Marc Lavallée wrote: Hi Étienne. etienne deleflie edelef...@gmail.com a écrit : ... and then ambisonics is suddenly available to masses of people, for very cheap, and with a consistent and quality spatial experience (assuming the HRTF decoding can be done right). Etienne HRTF decoding is the problem here. Finding a proper HRTF profile by trying many (over of hundred) is not a solution; realistic binaural reproduction works only when I listen to my own binaural recordings. So, to enjoy mass produced ambisonics, I'd need personalized HRTF measurements, a service that is not cheap and non-existent for a majority of HRTF challenged people; for us, decoding ambisonics over 4 speakers is a better option, It is undeniable that listening to FOA over a bunch of speakers will mess up your 'personallised (actual) HRTFs' considerably.. ??? Frankly, this is a messed up statement. You need HRTFs if listening via headphones. When listening over speakers decoding ambisonics over 4 speakers is a better option, , you are listening via the the superposition of several of your natural HRTFs with varying amplitudes and delays. In the time domain this is not equivalent your HRIR for any real source. Interpolation between these several speaker-head IRs will occur at the sweet spot to give more or less correct ILD and ITD values, but outside of the sweet spot, and at high frequencies, the resulting IR is alien. Or you are just listening to the model of a (natural, complete, ideal) soundfield, even if this soundfield is reduced? you are listening via the the superposition of several of your natural HRTFs with varying amplitudes and delays. Does this also happen if you/I attend a concert? I had to ask this one, for further clarification. On 21/12/2013 10:58, Stefan Schreiber wrote: Just for clarification. (Nobody corrected this.) The Ambisonic scientologists don't want to play? In 1901, Allen Upward http://en.wikipedia.org/wiki/Allen_Upward coined /Scientology/ as a disparaging term, to indicate a blind, unthinking acceptance of scientific doctrine http://en.wikipedia.org/wiki/Scientology Naaah. I am just a musician, and I always like to question theories, including your's - because you have presented a technical/scientific theory, or at least some interpretation of what happens if FOA is decoded via 4 loudspeakers! The latter ain't be perfect, but this is certainly not related to binaural representation. (But I am aware that we are listening with two ears, at least in the normal case! ) And: I don't adhere to any Scientologist community or network...;-) The undeniable tag doesn't help a lot, BTW. Thanks for that. De nada! (I just wanted to express my belief that most to all theories are not undeniable. Further reading: Wittgenstein, Über Gewissheit. And Karl Popper basically says that theories can be easily falsified, whereas the verification is a more complex issue. Of course, scientologist philosophers won't prove my argument...O:-) ) Best, Stefan Just for clarification. (Nobody corrected this.) The undeniable tag doesn't help a lot, BTW. Superposition of IRs is a fact of life. Best, Stefan Schreiber ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
Fri, 20 Dec 2013 22:02:26 -0800, Aaron Heller hel...@ai.sri.com a écrit : On Fri, Dec 20, 2013 at 7:40 PM, David Worrall worr...@avatar.com.auwrote: I remember reading that, with exposure, human's audio-processing hardware can adapt to/learn how to use a non-optimal HRTF, given a bit of time. Does anyone have a reference for this? I don't know about 'non-optimal', but we can learn new ones by cross calibration with other senses, and apparently we don't forget the old ones. I have access to an Android tablet with a 4.2 OS, so I will train myself using the Ambi Explorer app, hoping it won't decalibrate my brain! ;-) Here, we demonstrate the existence of ongoing spatial calibration in the adult human auditory system. The spectral elevation cues of human subjects were disrupted by modifying their outer ears (pinnae) with molds. Although localization of sound elevation was dramatically degraded immediately after the modification, accurate performance was steadily reacquired. Interestingly, learning the new spectral cues did not interfere with the neural representation of the original cues, as subjects could localize sounds with both normal and modified pinnae. So it means that a good localizer can be trained, and can use nonindividualized HRTFs. The suspension of disbelief is already possible with stereo... Sat, 21 Dec 2013 09:55:03 +, dw d...@dwareing.plus.com a écrit : http://128.102.119.100/publications/wenzel_1993_Localization_Head_Related.pdf Thanks for the article. An excerpt from the conclusion: ...the use of nonindividualized transforms primarily results in an increase in the rate of front-to-back confusions. It is possible that both this effect and the slight overall degradation in performance are due to the subjects' inexperience with the task, and may be mitigated by further training. N.B: 128.102.119.100 = human-factors.arc.nasa.gov Sat, 21 Dec 2013 12:01:45 +, dw d...@dwareing.plus.com a écrit : When listening over speakers decoding ambisonics over 4 speakers is a better option, , you are listening via the the superposition of several of your natural HRTFs with varying amplitudes and delays. In the time domain this is not equivalent your HRIR for any real source. Interpolation between these several speaker-head IRs will occur at the sweet spot to give more or less correct ILD and ITD values, but outside of the sweet spot, and at high frequencies, the resulting IR is alien. My comprehension of Ambisonics is that the listener's head (in the sweetest spot) is exposed to one coherent approximation of a reproduced (or synthesized) sound field, not to a set of directional waves coming from the speakers (one directional wave per speaker). Understanding Ambisonics is already difficult, and I'm less comfortable with this concept based on the superposition of natural HRTFs. -- Marc ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
I have been a little unwell so I have not joined this discussion.I have a theory (hope, wish) that a super HRTF can be designed which can actually improve the accuracy with which we can localize and this will work for most people Umashankar Sent from my Windows Phone From: Marc Lavallée Sent: 21-12-2013 21:54 To: sursound@music.vt.edu Subject: Re: [Sursound] Upcoming Android apps ambisonic related Fri, 20 Dec 2013 22:02:26 -0800, Aaron Heller hel...@ai.sri.com a écrit : On Fri, Dec 20, 2013 at 7:40 PM, David Worrall worr...@avatar.com.auwrote: I remember reading that, with exposure, human's audio-processing hardware can adapt to/learn how to use a non-optimal HRTF, given a bit of time. Does anyone have a reference for this? I don't know about 'non-optimal', but we can learn new ones by cross calibration with other senses, and apparently we don't forget the old ones. I have access to an Android tablet with a 4.2 OS, so I will train myself using the Ambi Explorer app, hoping it won't decalibrate my brain! ;-) Here, we demonstrate the existence of ongoing spatial calibration in the adult human auditory system. The spectral elevation cues of human subjects were disrupted by modifying their outer ears (pinnae) with molds. Although localization of sound elevation was dramatically degraded immediately after the modification, accurate performance was steadily reacquired. Interestingly, learning the new spectral cues did not interfere with the neural representation of the original cues, as subjects could localize sounds with both normal and modified pinnae. So it means that a good localizer can be trained, and can use nonindividualized HRTFs. The suspension of disbelief is already possible with stereo... Sat, 21 Dec 2013 09:55:03 +, dw d...@dwareing.plus.com a écrit : http://128.102.119.100/publications/wenzel_1993_Localization_Head_Related.pdf Thanks for the article. An excerpt from the conclusion: ...the use of nonindividualized transforms primarily results in an increase in the rate of front-to-back confusions. It is possible that both this effect and the slight overall degradation in performance are due to the subjects' inexperience with the task, and may be mitigated by further training. N.B: 128.102.119.100 = human-factors.arc.nasa.gov Sat, 21 Dec 2013 12:01:45 +, dw d...@dwareing.plus.com a écrit : When listening over speakers decoding ambisonics over 4 speakers is a better option, , you are listening via the the superposition of several of your natural HRTFs with varying amplitudes and delays. In the time domain this is not equivalent your HRIR for any real source. Interpolation between these several speaker-head IRs will occur at the sweet spot to give more or less correct ILD and ITD values, but outside of the sweet spot, and at high frequencies, the resulting IR is alien. My comprehension of Ambisonics is that the listener's head (in the sweetest spot) is exposed to one coherent approximation of a reproduced (or synthesized) sound field, not to a set of directional waves coming from the speakers (one directional wave per speaker). Understanding Ambisonics is already difficult, and I'm less comfortable with this concept based on the superposition of natural HRTFs. -- Marc ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound -- next part -- An HTML attachment was scrubbed... URL: https://mail.music.vt.edu/mailman/private/sursound/attachments/20131221/acdadbe6/attachment.html ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
On 21/12/2013 13:28, Stefan Schreiber wrote: dw wrote: On 21/12/2013 10:58, Stefan Schreiber wrote: dw wrote: On 12/12/2013 12:40, Marc Lavallée wrote: Hi Étienne. etienne deleflie edelef...@gmail.com a écrit : ... and then ambisonics is suddenly available to masses of people, for very cheap, and with a consistent and quality spatial experience (assuming the HRTF decoding can be done right). Etienne HRTF decoding is the problem here. Finding a proper HRTF profile by trying many (over of hundred) is not a solution; realistic binaural reproduction works only when I listen to my own binaural recordings. So, to enjoy mass produced ambisonics, I'd need personalized HRTF measurements, a service that is not cheap and non-existent for a majority of HRTF challenged people; for us, decoding ambisonics over 4 speakers is a better option, It is undeniable that listening to FOA over a bunch of speakers will mess up your 'personallised (actual) HRTFs' considerably.. ??? Frankly, this is a messed up statement. You need HRTFs if listening via headphones. When listening over speakers decoding ambisonics over 4 speakers is a better option, , you are listening via the the superposition of several of your natural HRTFs with varying amplitudes and delays. In the time domain this is not equivalent your HRIR for any real source. Interpolation between these several speaker-head IRs will occur at the sweet spot to give more or less correct ILD and ITD values, but outside of the sweet spot, and at high frequencies, the resulting IR is alien. Or you are just listening to the model of a (natural, complete, ideal) soundfield, even if this soundfield is reduced? , despite There is NO RECONSRUCTION of the original soundfield, despite the microphone by that name, and hype, if you understand 'field' to mean a volume or plane. At best it reconstructs the sound at a point, (in terms of dimensions in terms of wavelength) and CREATES a new soundfield, which may be plausable. you are listening via the the superpositioBun of several of your natural HRTFs with varying amplitudes and delays. Does this also happen if you/I attend a concert? I had to ask this one, for further clarification. Not normally, but I suppose it could if you were surounded by singers who were in-phase and in tune. (see Griesinger) http://www.davidgriesinger.com/Acous...b_sound_3.pptx http://www.davidgriesinger.com/Acoustics_Today/Pitch,%20Timbre,%20Source%20Separation_talk_web_sound_3.pptx Note that I did not say that it 'mattered' if you listen via an 'alien' HRTF, but it might. You just don't get your 'own' whether by listening to a real speaker, or through DSP convolution. At least you can stay in the sweet spot using headphones, and you get a chance to 'learn' it before it all changes again! On 21/12/2013 10:58, Stefan Schreiber wrote: Just for clarification. (Nobody corrected this.) The Ambisonic scientologists don't want to play? In 1901, Allen Upward http://en.wikipedia.org/wiki/Allen_Upward coined /Scientology/ as a disparaging term, to indicate a blind, unthinking acceptance of scientific doctrine http://en.wikipedia.org/wiki/Scientology Naaah. I am just a musician, and I always like to question theories, including your's - because you have presented a technical/scientific theory, or at least some interpretation of what happens if FOA is decoded via 4 loudspeakers! The latter ain't be perfect, but this is certainly not related to binaural representation. (But I am aware that we are listening with two ears, at least in the normal case! ) I would never accuse _you_ of not wanting to play, or having a strange religion, or having undue respect for The Science.. And: I don't adhere to any Scientologist community or network...;-) The undeniable tag doesn't help a lot, BTW. Thanks for that. De nada! (I just wanted to express my belief that most to all theories are not undeniable. Further reading: Wittgenstein, Über Gewissheit. And Karl Popper basically says that theories can be easily falsified, whereas the verification is a more complex issue. Of course, scientologist philosophers won't prove my argument...O:-) ) It is pretty undeniable that each driven (working..) speaker in an Ambisonic array will make a sound which will arrive at each ear... and is simply summed in the time domain, or must be summed as vectors/phasors (taking into account phase/delay, as well as amplitude) in the frequency domain. I would not call this 'theories' and certainly not mine..http://en.wikipedia.org/wiki/Superposition_principle Best, Stefan Just for clarification. (Nobody corrected this.) The undeniable tag doesn't help a lot, BTW. Superposition of IRs is a fact of life. Best, Stefan Schreiber ___ Sursound mailing list Sursound@music.vt.edu
Re: [Sursound] Upcoming Android apps ambisonic related
On 21/12/2013 16:24, Marc Lavallée wrote: My comprehension of Ambisonics is that the listener's head (in the sweetest spot) is exposed to one coherent approximation of a reproduced (or synthesized) sound field, not to a set of directional waves coming from the speakers (one directional wave per speaker). Understanding Ambisonics is already difficult, and I'm less comfortable with this concept based on the superposition of natural HRTFs. -- Marc ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound If you LP filter HRIRs sufficiently low, then small delays represent small phase changes and you no longer get lumps and bumps in the frequency response when you sum the IRs. 'Interpolation' between the HRTFs which vary in amplitude (and polarity), with source position, can result in the desired ITD, for example. I think BLaH went through this exercise. It does not mean you don't get some 'lumps and bumps' in the direct arrival higher up in frequency. With sufficient listening room refections adding incoherently the overall frequency response may be ok, although I am quite keen myself on the relative response between the two (direct/reflected) ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
On Sat, Dec 21, 2013 at 11:24:45AM -0500, Marc Lavallée wrote: My comprehension of Ambisonics is that the listener's head (in the sweetest spot) is exposed to one coherent approximation of a reproduced (or synthesized) sound field, not to a set of directional waves coming from the speakers (one directional wave per speaker). The listener is exposed to to a set of directional waves coming from the speakers (one directional wave per speaker) which combine into an approximation of the original soundfield - there is no conflict between the two views. If the approximation is good enough, the way it is constructed becomes irrelevant and you won't hear the speakers as separate sources. A phantom (between the speakers) source will result in superposition (i.e. interpolation) of HRIRs, even when listening to a speaker system. If the same happens when binaural signals are synthesized, that should not be a problem if it wasn't one for the speakers system. In other words, the fact that interpolating HRIRs will not result in the exact HRIR for the intented direction should be irrelevant IFF the signals that are combined would produce a convincing soundfield when reproduced over speakers. Ciao, -- FA A world of exhaustive, reliable metadata would be an utopia. It's also a pipe-dream, founded on self-delusion, nerd hubris and hysterically inflated market opportunities. (Cory Doctorow) ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
Sat, 21 Dec 2013 18:40:19 +, Fons Adriaensen f...@linuxaudio.org a écrit : On Sat, Dec 21, 2013 at 11:24:45AM -0500, Marc Lavallée wrote: My comprehension of Ambisonics is that the listener's head (in the sweetest spot) is exposed to one coherent approximation of a reproduced (or synthesized) sound field, not to a set of directional waves coming from the speakers (one directional wave per speaker). The listener is exposed to to a set of directional waves coming from the speakers (one directional wave per speaker) which combine into an approximation of the original soundfield - there is no conflict between the two views. Yes, I understand that (intuitively); what I meant (you excluded the last part of my message) is that I prefer to consider Ambisonics as a way to produce a sound field that is coherent enough (in the sweet spot), to not care (much) about the all the interactions between the listener and each speaker. If the approximation is good enough, the way it is constructed becomes irrelevant and you won't hear the speakers as separate sources. A phantom (between the speakers) source will result in superposition (i.e. interpolation) of HRIRs, even when listening to a speaker system. If the same happens when binaural signals are synthesized, that should not be a problem if it wasn't one for the speakers system. Right. What matters is the resulting sound field in the listening spot. In other words, the fact that interpolating HRIRs will not result in the exact HRIR for the intented direction should be irrelevant IFF the signals that are combined would produce a convincing soundfield when reproduced over speakers. Ciao, Thats' clear enough. Thanks for your explanation. -- Marc ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
I remember reading that, with exposure, human's audio-processing hardware can adapt to/learn how to use a non-optimal HRTF, given a bit of time. Does anyone have a reference for this? David On 15/12/2013, at 5:57 PM, Marc Lavallée wrote: Hi Dave. I never tried head tracking while listening to stereo or Ambisonics (I'm not that much of an insider). I'm optimistic about it, even with virtual microphones; but I suspect that the contribution of head tracking would then be limited to the interpretation of level differences and transitions between the left and right. What I miss is a realistic HRTF rendering experience (without head tracking). For every HRTF I tried (from the KEMAR and LISTEN sets), as with stereo, front sources were always in the head, not at the front; the front test tone was just louder then the rear one. I don't know what are the right conditions to experience good HRTF based localization (in a acousmatic context, without visual cues). I don't know if using a personal (measured) HRTF would be better; I just assume that it would be better because my own binaural recordings sound quite right, but probably just for me (to be verified) because I experienced the real sound scenes while recording them. -- Marc Sun, 15 Dec 2013 13:50:09 +, Dave Malham dave.mal...@york.ac.uk a écrit : Hi Marc, I think it is, perhaps, a little pessimistic to talk of needing to assess dozens of hrtf's to find the one that's right for for you, if you have head tracking in use. My experience with this dates back 20 years to the days of the Lake DSP Huron systems when I first heard this - even without specific hrtfs switching the the head tracking on was enough to change the system from not working (for me) to working. The head tracking (done with a Polyhemus sensor controlling the processing of FOA B format signals prior to decoding) was enough with no need to select hrtf's. I would suspect that having just a few to select from would be enough. Dave ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound __ Prof. Dr. David Worrall Emerging Audio Research (EAR) Audio Department International Audio Laboratories Erlangen Fraunhofer-Institut für Integrierte Schaltungen IIS Am Wolfsmantel 33 91058 Erlangen Telefon +49 (0) 91 31 / 7 76-62 77 Fax +49 (0) 91 31 / 7 76-20 99 E-Mail: david.worr...@iis.fraunhofer.de Internet: www.iis.fraunhofer.de Senior Adjunct Research Fellow, Australian National University. david.worr...@anu.edu.au -- next part -- An HTML attachment was scrubbed... URL: https://mail.music.vt.edu/mailman/private/sursound/attachments/20131221/90a012e3/attachment.html ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
On Fri, Dec 20, 2013 at 7:40 PM, David Worrall worr...@avatar.com.auwrote: I remember reading that, with exposure, human's audio-processing hardware can adapt to/learn how to use a non-optimal HRTF, given a bit of time. Does anyone have a reference for this? I don't know about 'non-optimal', but we can learn new ones by cross calibration with other senses, and apparently we don't forget the old ones. Aaron (hel...@ai.sri.com) Nature Neuroscience 1, 417 - 421 (1998) doi:10.1038/1633 Relearning sound localization with new ears Paul M. Hofman, Jos G.A. Van Riswick A. John Van Opstal University of Nijmegen, Department of Medical Physics and Biophysics, Geert Grooteplein 21, NL-6525 EZ Nijmegen, The Netherlands Correspondence should be addressed to A. John Van Opstal joh...@mbfys.kun.nl Because the inner ear is not organized spatially, sound localization relies on the neural processing of implicit acoustic cues. To determine a sound's position, the brain must learn and calibrate these cues, using accurate spatial feedback from other sensorimotor systems. Experimental evidence for such a system has been demonstrated in barn owls, but not in humans. Here, we demonstrate the existence of ongoing spatial calibration in the adult human auditory system. The spectral elevation cues of human subjects were disrupted by modifying their outer ears (pinnae) with molds. Although localization of sound elevation was dramatically degraded immediately after the modification, accurate performance was steadily reacquired. Interestingly, learning the new spectral cues did not interfere with the neural representation of the original cues, as subjects could localize sounds with both normal and modified pinnae. Full text at: http://www.nature.com/neuro/journal/v1/n5/full/nn0998_417.html -- next part -- An HTML attachment was scrubbed... URL: https://mail.music.vt.edu/mailman/private/sursound/attachments/20131220/4d9a2494/attachment.html ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
Hi Marc, I think it is, perhaps, a little pessimistic to talk of needing to assess dozens of hrtf's to find the one that's right for for you, if you have head tracking in use. My experience with this dates back 20 years to the days of the Lake DSP Huron systems when I first heard this - even without specific hrtfs switching the the head tracking on was enough to change the system from not working (for me) to working. The head tracking (done with a Polyhemus sensor controlling the processing of FOA B format signals prior to decoding) was enough with no need to select hrtf's. I would suspect that having just a few to select from would be enough. Dave On 14 December 2013 16:34, Marc Lavallée m...@hacklava.net wrote: Hi Stefan. Stefan Schreiber st...@mail.telepac.pt a écrit : For us means in this context: A club of enthusiasts and some academics. That us, in the context of mass distribution, statistically means a lot of people unable to enjoy Ambisonics using generic HRTFs; there's also a whole lot of them who will refuse to try dozens of HRTFs to find the right one. Among the mass of people, how many actually listen to stereo the right way? It's even worse with 5.1 surround. It is not meant in a despective way or anything related, but this is exactly the problem: Why would we change anything if things already do work, and work in a wonderful and most flexible way anyway? Let's wait; there's tons of apps competing to capture the attention of phone and tablet users. There's no single killer app for Ambisonics; it's a long term option for capturing, mastering, distributing and listening to audio. I beg to differe. Maybe people outside any insider group should be enabled to test if some available HRTF sets work for them ? This is what Hector's programs (or apps) are about. Of course! I agree, and I hope that the app will bring more people to the insider group. Why would you stream for audio channels from a mobile to a decoder if you can integrate the decoder into the phone? (Come in Hector's apps.) Because the decoder in the phone, for a few unlucky people, might not work as well as their home decoder. A phone can be a source for Ambisonics material, in the form of audio tracks in a video stream. There's already ways to air stream video from a phone/tablet to a television set, probably with 5.1 audio. We are talking about a different use anyway. (At home and mobile .) Best, Stefan Same use (listening), different context (home vs anywhere), one better than the other depending on your preference and your experience of Ambisonics listening. It's undeniable that the Android app will provide a new way to enjoy Ambisonics; exploring a sound field with virtual stereo microphones should be impressive enough for many phone users. -- Marc P.S.: I am unaware if people already can change between different HRTF sets/data, but this would be a minor issue. ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound -- As of 1st October 2012, I have retired from the University. These are my own views and may or may not be shared by the University Dave Malham Honorary Fellow, Department of Music The University of York York YO10 5DD UK 'Ambisonics - Component Imaging for Audio' -- next part -- An HTML attachment was scrubbed... URL: https://mail.music.vt.edu/mailman/private/sursound/attachments/20131215/48145e3e/attachment.html ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
Hi Dave. I never tried head tracking while listening to stereo or Ambisonics (I'm not that much of an insider). I'm optimistic about it, even with virtual microphones; but I suspect that the contribution of head tracking would then be limited to the interpretation of level differences and transitions between the left and right. What I miss is a realistic HRTF rendering experience (without head tracking). For every HRTF I tried (from the KEMAR and LISTEN sets), as with stereo, front sources were always in the head, not at the front; the front test tone was just louder then the rear one. I don't know what are the right conditions to experience good HRTF based localization (in a acousmatic context, without visual cues). I don't know if using a personal (measured) HRTF would be better; I just assume that it would be better because my own binaural recordings sound quite right, but probably just for me (to be verified) because I experienced the real sound scenes while recording them. -- Marc Sun, 15 Dec 2013 13:50:09 +, Dave Malham dave.mal...@york.ac.uk a écrit : Hi Marc, I think it is, perhaps, a little pessimistic to talk of needing to assess dozens of hrtf's to find the one that's right for for you, if you have head tracking in use. My experience with this dates back 20 years to the days of the Lake DSP Huron systems when I first heard this - even without specific hrtfs switching the the head tracking on was enough to change the system from not working (for me) to working. The head tracking (done with a Polyhemus sensor controlling the processing of FOA B format signals prior to decoding) was enough with no need to select hrtf's. I would suspect that having just a few to select from would be enough. Dave ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
Hi Stefan. Stefan Schreiber st...@mail.telepac.pt a écrit : For us means in this context: A club of enthusiasts and some academics. That us, in the context of mass distribution, statistically means a lot of people unable to enjoy Ambisonics using generic HRTFs; there's also a whole lot of them who will refuse to try dozens of HRTFs to find the right one. Among the mass of people, how many actually listen to stereo the right way? It's even worse with 5.1 surround. It is not meant in a despective way or anything related, but this is exactly the problem: Why would we change anything if things already do work, and work in a wonderful and most flexible way anyway? Let's wait; there's tons of apps competing to capture the attention of phone and tablet users. There's no single killer app for Ambisonics; it's a long term option for capturing, mastering, distributing and listening to audio. I beg to differe. Maybe people outside any insider group should be enabled to test if some available HRTF sets work for them ? This is what Hector's programs (or apps) are about. Of course! I agree, and I hope that the app will bring more people to the insider group. Why would you stream for audio channels from a mobile to a decoder if you can integrate the decoder into the phone? (Come in Hector's apps.) Because the decoder in the phone, for a few unlucky people, might not work as well as their home decoder. A phone can be a source for Ambisonics material, in the form of audio tracks in a video stream. There's already ways to air stream video from a phone/tablet to a television set, probably with 5.1 audio. We are talking about a different use anyway. (At home and mobile .) Best, Stefan Same use (listening), different context (home vs anywhere), one better than the other depending on your preference and your experience of Ambisonics listening. It's undeniable that the Android app will provide a new way to enjoy Ambisonics; exploring a sound field with virtual stereo microphones should be impressive enough for many phone users. -- Marc P.S.: I am unaware if people already can change between different HRTF sets/data, but this would be a minor issue. ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
Marc Lavallée wrote: Because the decoder in the phone, for a few unlucky people, might not work as well as their home decoder. I don't think I am so confused as I am sometimes read: The home decoder makes obviously a lot of sense if you want to listen to surround/Ambisonics at home. (The context issue, which you mention later...) You can't use the home decoder in the mobile case, without any further proof... If you are listening to Ambisonics on your phone or tablet, it doesn't make a lot of sense to separate the source (audio files) and decoder stage at all. (Don't forget that the phone has to decode the MP3/AAC files, in any case! Do the same in the surround case, to have the same ease from the consumer perspective.) A phone can be a source for Ambisonics material, in the form of audio tracks in a video stream. There's already ways to air stream video from a phone/tablet to a television set, probably with 5.1 audio. Yes, but this is not related to audio decoding in the phone. (The phone serves just the memory for AV files. Similar case: The camera photos you might watch/show on a TV, etc.) We are talking about a different use anyway. (At home and mobile .) Best, Stefan Same use (listening), different context (home vs anywhere), one better than the other depending on your preference and your experience of Ambisonics listening. It's undeniable that the Android app will provide a new way to enjoy Ambisonics; exploring a sound field with virtual stereo microphones should be impressive enough for many phone users. -- Marc It is not only impressive, it would be for many the only way to listen to a soundfield, to get into touch with surround/3D audio etc. (Considering that decoding of 5.1 surround or FOA/HOA to headphones is not anything new, we are talking about applications which reach people who are not experts/insiders. I said this.- I fully agree with you that there doesn't exist any iOS app yet... Any lurking Apple associates are warmly invited to fill up this obvious gap in their appstore.:-D ) Best, Stefan P.S.: Binaural decoding on a phone (to cheap phone headphones) works for UHJ, 5.1, FOA, and even different Mpeg standards and HOA. At least in principle. ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
--On 12 December 2013 01:41 + Stefan Schreiber st...@mail.telepac.pt wrote: You won't need any base station for HT, by now! If you have no fixed reference, how do you cope? Do you add a compass (and have a command to set the direction of front), or do you allow the front to drift back into place when there is no movement? Paul -- Paul Hodges ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
The first part is overdue (and many thanks to Hector!), the second part is a nice demonstration. But from a CE perspective, I highly doubt that normal consumers would glue (in my terms) their smartphone to their head. of course not ... but the point is that the demonstration is accessible by all with a smartphone, ... and if the demonstration is successful then that can only lead to the development of cheap and small 'clip-on' gyro gysmos (available for $12.99).. that clip on to headsets or ear buds ... and then ambisonics is suddenly available to masses of people, for very cheap, and with a consistent and quality spatial experience (assuming the HRTF decoding can be done right). Etienne This is why I am stunned that no known headphone manufacturer is using any of all these widely available and really viable motion-tracking/gyroscope chips, by now. And: Things could be done in such an easier manner than ever before, by now: http://www.smyth-research.com/technology.html The Realiser system includes a small device atop the headphone headband and another small device at the front of the room, which together monitor the position of the listener's head every five milliseconds. (Bayer Headzone is similar and overcomplicated, from a current perspective. http://www.beyerdynamic.de/shop/headzone-headphone-surround-system.html You won't need any base station for HT, by now!) You can replace both former solutions with available motion tracking ICs. 200 Hz is no problem by now. (The Oculus Rift people give some specifications. I already wrote about this, some time ago. ) Beside of this, I have written so often about the Wii control, iPhone sensors, Glass motion sensors and Oculus Rift before that I seem entitled to utter my private opinion. See also my recent posting of the person who 3D-printed a frame for a smartphone as stereo display system for a 3D glass. (VR systems need HT and fast visual updates. We are all in-favour of head-tracked 5.1/Ambisonics decoding, so to speak) Many thanks to Hector Centeno, anyway. ( It has become way too obvious that any current developments in audio technology happen at an incredibly slow pace, compared to probably any other area. This is probably also partially my own fault, just writing about possible solutions and not actually doing them, cos I have a full-time job and life... :-D I also would not blame the music or audiophile industries, which don't know a lot about such complicated topics like technology or music... On a more positive note, Hector has written some of these apps for mobile devices which people (consumers) might actually use in tough real-world/daily life conditions! This wasn't about the usual Linux environment for connaisseurs, although some other people might object that these apps would even not exist without Linux... Maybe this was not the topic we should discuss! O:-) ) Best, Stefan Schreiber If this combination of technology is not the future of ambisonics then I dont think anything is! Can I ask ... what is the latency on the head-tracking? Etienne On Wed, Dec 11, 2013 at 2:25 AM, Hector Centeno hcen...@gmail.com wrote: Hello all, I just wanted to share with this list information about two Android apps I've been working on and that I will release soon. I made them because I thought it would be great to be able to listen to ambisonic recordings in a portable way without the need of a full size computer. The first app is called AmbiExplorer and it's a first order decoder to stereo, with the option of choosing binaural or virtual microphones. You can peform soundfield rotation and microphone polar patten selection. It will also work with the device's orientation sensors so you could attach your device to headphones and have head-tracked binaural listening. The second app is called TetraFile and it's a port of the offline command line utility part of Fons' TetraProc. I made this so I could connect my portable recorder (in card reader mode) directly to my phone via USB OTG, transfer the A-format files and do a conversion to B-format and listen using AmbiExplorer. It will read your tetrafile calibration files from your phone's storage. More info and a video demo are available here: http://hcenteno.net/software.html Any comments are welcome. Best, Hector Centeno ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound -- http://etiennedeleflie.net ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
Hi Étienne. etienne deleflie edelef...@gmail.com a écrit : ... and then ambisonics is suddenly available to masses of people, for very cheap, and with a consistent and quality spatial experience (assuming the HRTF decoding can be done right). Etienne HRTF decoding is the problem here. Finding a proper HRTF profile by trying many (over of hundred) is not a solution; realistic binaural reproduction works only when I listen to my own binaural recordings. So, to enjoy mass produced ambisonics, I'd need personalized HRTF measurements, a service that is not cheap and non-existent for a majority of HRTF challenged people; for us, decoding ambisonics over 4 speakers is a better option, and streaming ambisonics from a phone with blutooth to a classic decoder would work. With ambisonics, there's many solutions. -- Marc ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
Paul Hodges wrote: --On 12 December 2013 01:41 + Stefan Schreiber st...@mail.telepac.pt wrote: You won't need any base station for HT, by now! If you have no fixed reference, how do you cope? GPS, relative GPS? Do you add a compass (and have a command to set the direction of front), or do you allow the front to drift back into place when there is no movement? Gyroscope, accelerometer... Best, Stefan ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
Marc Lavallée wrote: Hi Étienne. etienne deleflie edelef...@gmail.com a écrit : ... and then ambisonics is suddenly available to masses of people, for very cheap, and with a consistent and quality spatial experience (assuming the HRTF decoding can be done right). Etienne HRTF decoding is the problem here. for us, decoding ambisonics over 4 speakers is a better option, and streaming ambisonics from a phone with blutooth to a classic decoder would work. With ambisonics, there's many solutions. -- Marc For us means in this context: A club of enthusiasts and some academics. It is not meant in a despective way or anything related, but this is exactly the problem: Why would we change anything if things already do work, and work in a wonderful and most flexible way anyway? I beg to differe. Maybe people outside any insider group should be enabled to test if some available HRTF sets work for them ? This is what Hector's programs (or apps) are about. Why would you stream for audio channels from a mobile to a decoder if you can integrate the decoder into the phone? (Come in Hector's apps.) We are talking about a different use anyway. (At home and mobile .) Best, Stefan P.S.: I am unaware if people already can change between different HRTF sets/data, but this would be a minor issue. ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
umashankar manthravadi wrote: two years ago, I acquired a motor cycle helmet with the intention of mounting eight headphones to listen to ambisonics without hrtf. i was going to use it with a 20 dollar dolby 7.1 usb device.I did not go head because I realized I would still need headtracking. by the cell phone does not have to be on top of the head. it can be in a small bag handing at the back of the head, or even one side. it merely needs to move with the head. umashankar But IF we already talk about this: You could design a small device with the battery, position/HT ICs and the (bluetooth) transmittor. Or: Build this into the headphone, the integrated solution Beyer and Sennheiser are seemingly not able to deliver - as there is supposedly no market, I guess. Whole the Oculus Rift is supposed to cost less than a high end smartphone... http://en.wikipedia.org/wiki/Oculus_Rift Initial prototypes used a Hillcrest Labs 3DoF head tracker that is normally 125 Hz, with a special firmware that John Carmack requested which makes it run at 250 Hz, tracker latency being vital due to the dependency of virtual reality's realism on response time. The latest version includes Oculus' new 1000 Hz Adjacent Reality Tracker that will allow for much lower latency tracking than almost any other tracker. It uses a combination of 3-axis gyros, accelerometers, and magnetometers, which make it capable of absolute (relative to earth) head orientation tracking without drift.[15][22] Just to answer some questions from before... (I have posted about this way before.) Best, Stefan Date: Thu, 12 Dec 2013 07:40:03 -0500 From: m...@hacklava.net To: sursound@music.vt.edu Subject: Re: [Sursound] Upcoming Android apps ambisonic related Hi Étienne. etienne deleflie edelef...@gmail.com a écrit : ... and then ambisonics is suddenly available to masses of people, for very cheap, and with a consistent and quality spatial experience (assuming the HRTF decoding can be done right). Etienne HRTF decoding is the problem here. Finding a proper HRTF profile by trying many (over of hundred) is not a solution; realistic binaural reproduction works only when I listen to my own binaural recordings. So, to enjoy mass produced ambisonics, I'd need personalized HRTF measurements, a service that is not cheap and non-existent for a majority of HRTF challenged people; for us, decoding ambisonics over 4 speakers is a better option, and streaming ambisonics from a phone with blutooth to a classic decoder would work. With ambisonics, there's many solutions. -- Marc ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
On 12/12/2013 12:40, Marc Lavallée wrote: Hi Étienne. etienne deleflie edelef...@gmail.com a écrit : ... and then ambisonics is suddenly available to masses of people, for very cheap, and with a consistent and quality spatial experience (assuming the HRTF decoding can be done right). Etienne HRTF decoding is the problem here. Finding a proper HRTF profile by trying many (over of hundred) is not a solution; realistic binaural reproduction works only when I listen to my own binaural recordings. So, to enjoy mass produced ambisonics, I'd need personalized HRTF measurements, a service that is not cheap and non-existent for a majority of HRTF challenged people; for us, decoding ambisonics over 4 speakers is a better option, It is undeniable that listening to FOA over a bunch of speakers will mess up your 'personallised (actual) HRTFs' considerably.. It is debatable whether putting mics in your own ears yields anything very useful. Arguing that HRTFs are like fingerprints misses the fact that the detailed individual patterns of fingerprints have no known function (apart from forensics) You just have to have 'some', for antislip or touch reasons. The analogy might turn out well, after all. and streaming ambisonics from a phone with blutooth to a classic decoder would work. With ambisonics, there's many solutions. -- Marc ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
On 12/12/2013 03:26 PM, Stefan Schreiber wrote: Paul Hodges wrote: --On 12 December 2013 01:41 + Stefan Schreiber st...@mail.telepac.pt wrote: You won't need any base station for HT, by now! If you have no fixed reference, how do you cope? GPS, relative GPS? i doubt it would be precise enough. the subject is not moving, after all. Do you add a compass (and have a command to set the direction of front), or do you allow the front to drift back into place when there is no movement? how good are these built-in compasses? i still have a very dumb smartphone... Gyroscope, accelerometer... but those _will_ accumulate errors. doing dead reckoning with just a gyro and accelerometer requires double integration and is, ahem, prone to difficulties. check out pynchon's gravity's rainbow for a novel approach to the problem ;) executive summary: if you are going to do it for less than a few seconds, you will have to choose _very_ big targets. the situation is a bit less dire if all you care for is heading, but you will need a reference every once in a while to re-calibrate your reckoning, or else default to in the absence of head movement, drift back to due north orientation, like paul seid. which can be irritating and, in the case of physical soundscapes, disorienting. -- Jörn Nettingsmeier Lortzingstr. 11, 45128 Essen, Tel. +49 177 7937487 Meister für Veranstaltungstechnik (Bühne/Studio) Tonmeister VDT http://stackingdwarves.net ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
etienne deleflie wrote: The first part is overdue (and many thanks to Hector!), the second part is a nice demonstration. But from a CE perspective, I highly doubt that normal consumers would glue (in my terms) their smartphone to their head. of course not ... but the point is that the demonstration is accessible by all with a smartphone, ... and if the demonstration is successful then that can only lead to the development of cheap and small 'clip-on' gyro gysmos (available for $12.99).. that clip on to headsets or ear buds ... and then ambisonics is suddenly available to masses of people, for very cheap, and with a consistent and quality spatial experience (assuming the HRTF decoding can be done right). Etienne I fully agree. (And good headphones are not that cheap. If we still talk about Sennheiser and Beyer. But how we both have figured out, it could be an independent set which sends position data to a smartphone, and just would use any headphone. (For the decoding side, the number of mobile and fixed OS systems is quite limited. In the future, some JavaScript/HTML 5 solution might be general enough to do the job on any OS.) In this sense, we finally might not need Sennheiser and Beyer. An observation which frankly should build up a certain pressure Best, Stefan P.S.: A small hint for all ye lurking headphone developpers/engineers. :-D This is why I am stunned that no known headphone manufacturer is using any of all these widely available and really viable motion-tracking/gyroscope chips, by now. And: Things could be done in such an easier manner than ever before, by now: http://www.smyth-research.com/technology.html The Realiser system includes a small device atop the headphone headband and another small device at the front of the room, which together monitor the position of the listener's head every five milliseconds. (Bayer Headzone is similar and overcomplicated, from a current perspective. http://www.beyerdynamic.de/shop/headzone-headphone-surround-system.html You won't need any base station for HT, by now!) You can replace both former solutions with available motion tracking ICs. 200 Hz is no problem by now. (The Oculus Rift people give some specifications. I already wrote about this, some time ago. ) Beside of this, I have written so often about the Wii control, iPhone sensors, Glass motion sensors and Oculus Rift before that I seem entitled to utter my private opinion. See also my recent posting of the person who 3D-printed a frame for a smartphone as stereo display system for a 3D glass. (VR systems need HT and fast visual updates. We are all in-favour of head-tracked 5.1/Ambisonics decoding, so to speak) Many thanks to Hector Centeno, anyway. ( It has become way too obvious that any current developments in audio technology happen at an incredibly slow pace, compared to probably any other area. This is probably also partially my own fault, just writing about possible solutions and not actually doing them, cos I have a full-time job and life... :-D I also would not blame the music or audiophile industries, which don't know a lot about such complicated topics like technology or music... On a more positive note, Hector has written some of these apps for mobile devices which people (consumers) might actually use in tough real-world/daily life conditions! This wasn't about the usual Linux environment for connaisseurs, although some other people might object that these apps would even not exist without Linux... Maybe this was not the topic we should discuss! O:-) ) Best, Stefan Schreiber If this combination of technology is not the future of ambisonics then I dont think anything is! Can I ask ... what is the latency on the head-tracking? Etienne On Wed, Dec 11, 2013 at 2:25 AM, Hector Centeno hcen...@gmail.com wrote: Hello all, I just wanted to share with this list information about two Android apps I've been working on and that I will release soon. I made them because I thought it would be great to be able to listen to ambisonic recordings in a portable way without the need of a full size computer. The first app is called AmbiExplorer and it's a first order decoder to stereo, with the option of choosing binaural or virtual microphones. You can peform soundfield rotation and microphone polar patten selection. It will also work with the device's orientation sensors so you could attach your device to headphones and have head-tracked binaural listening. The second app is called TetraFile and it's a port of the offline command line utility part of Fons' TetraProc. I made this so I could connect my portable recorder (in card reader mode) directly to my phone via USB OTG, transfer the A-format files and do a conversion to B-format and listen using AmbiExplorer. It will read your tetrafile calibration files from your phone's storage. More info and a video demo are available here:
Re: [Sursound] Upcoming Android apps ambisonic related
Jörn Nettingsmeier wrote: On 12/12/2013 03:26 PM, Stefan Schreiber wrote: Paul Hodges wrote: --On 12 December 2013 01:41 + Stefan Schreiber st...@mail.telepac.pt wrote: You won't need any base station for HT, by now! If you have no fixed reference, how do you cope? GPS, relative GPS? i doubt it would be precise enough. the subject is not moving, after all. Do you add a compass (and have a command to set the direction of front), or do you allow the front to drift back into place when there is no movement? how good are these built-in compasses? i still have a very dumb smartphone... Gyroscope, accelerometer... but those _will_ accumulate errors. doing dead reckoning with just a gyro and accelerometer requires double integration and is, ahem, prone to difficulties. check out pynchon's gravity's rainbow for a novel approach to the problem ;) executive summary: if you are going to do it for less than a few seconds, you will have to choose _very_ big targets. the situation is a bit less dire if all you care for is heading, but you will need a reference every once in a while to re-calibrate your reckoning, or else default to in the absence of head movement, drift back to due north orientation, like paul seid. which can be irritating and, in the case of physical soundscapes, disorienting. The reference is either a measured GPS position, or the earth magnetic field? Executive summary for the AES and Tonmeistertagung 2014: You don't need an (objectively) exact position. You need a fixed point, and relative movement to this. This can be done, as in VR or newish cheap gaming devices. Best, Stefan P.S. Archimedes: Gib' mir einen festen Punkt, und ich werde die Welt aus den Angeln heben. For the English version, I recommend Google Translation...:-D P.S. 2: If you are not afraid of the NSA! die Welt aus den Angeln heben in any language, this is ... very suspect! (For the Romans, Archimedes was probably more than just a terror suspect. The rest is history.) P.S. 3: Don't do some automated translation of this citing from German to Arab, BTW! (And don't call your avatar Muhammad Archimedes in WoW, even a bigger mishap...) ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
Hector Centeno wrote: Hello all, I just wanted to share with this list information about two Android apps I've been working on and that I will release soon. I made them because I thought it would be great to be able to listen to ambisonic recordings in a portable way without the need of a full size computer. The first app is called AmbiExplorer and it's a first order decoder to stereo, with the option of choosing binaural or virtual microphones. You can peform soundfield rotation and microphone polar patten selection. It will also work with the device's orientation sensors so you could attach your device to headphones and have head-tracked binaural listening. The second app is called TetraFile and it's a port of the offline command line utility part of Fons' TetraProc. I made this so I could connect my portable recorder (in card reader mode) directly to my phone via USB OTG, transfer the A-format files and do a conversion to B-format and listen using AmbiExplorer. It will read your tetrafile calibration files from your phone's storage. More info and a video demo are available here: http://hcenteno.net/software.html Any comments are welcome. Best, Hector Centeno Thanks again for your apps, which seem to be a first in this area. The first app is called AmbiExplorer and it's a first order decoder to stereo, with the option of choosing binaural or virtual microphones. You can peform soundfield rotation and microphone polar patten selection. It will also work with the device's orientation sensors so you could attach your device to headphones and have head-tracked binaural listening. As you have seen, the latter could become the basis for some real-world product. (A small motion and orientation tracking device, which you could fix to your headphones, glasses or whereever. For the air interface, the best is if somebody sets a first standard for the data format(s). If not, every such device needs its own software on different platforms. This might not be that important in the beginning, but maybe later.) Well done! Stefan ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
On 12/12/2013 12:44, umashankar manthravadi wrote: two years ago, I acquired a motor cycle helmet with the intention of mounting eight headphones to listen to ambisonics without hrtf. i was going to use it with a 20 dollar dolby 7.1 usb device. It was not one of your better plans.. :-) ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
beg to differ... (paper to follow...) Dr Peter Lennox School of Technology, Faculty of Arts, Design and Technology University of Derby, UK e: p.len...@derby.ac.uk t: 01332 593155 From: Sursound [sursound-boun...@music.vt.edu] On Behalf Of dw [d...@dwareing.plus.com] Sent: 12 December 2013 23:02 To: sursound@music.vt.edu Subject: Re: [Sursound] Upcoming Android apps ambisonic related On 12/12/2013 12:44, umashankar manthravadi wrote: two years ago, I acquired a motor cycle helmet with the intention of mounting eight headphones to listen to ambisonics without hrtf. i was going to use it with a 20 dollar dolby 7.1 usb device. It was not one of your better plans.. :-) ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound The University of Derby has a published policy regarding email and reserves the right to monitor email traffic. If you believe this was sent to you in error, please select unsubscribe. Unsubscribe and Security information contact: info...@derby.ac.uk For all FOI requests please contact: f...@derby.ac.uk All other Contacts are at http://www.derby.ac.uk/its/contacts/ ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
On 12/12/2013 23:10, Peter Lennox wrote: beg to differ... (paper to follow...) Dr Peter Lennox I was wondering where my taxes went.. School of Technology, Faculty of Arts, Design and Technology University of Derby, UK e: p.len...@derby.ac.uk t: 01332 593155 From: Sursound [sursound-boun...@music.vt.edu] On Behalf Of dw [d...@dwareing.plus.com] Sent: 12 December 2013 23:02 To: sursound@music.vt.edu Subject: Re: [Sursound] Upcoming Android apps ambisonic related On 12/12/2013 12:44, umashankar manthravadi wrote: two years ago, I acquired a motor cycle helmet with the intention of mounting eight headphones to listen to ambisonics without hrtf. i was going to use it with a 20 dollar dolby 7.1 usb device. It was not one of your better plans.. :-) ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound The University of Derby has a published policy regarding email and reserves the right to monitor email traffic. If you believe this was sent to you in error, please select unsubscribe. Unsubscribe and Security information contact: info...@derby.ac.uk For all FOI requests please contact: f...@derby.ac.uk All other Contacts are at http://www.derby.ac.uk/its/contacts/ ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
finally! congratulations on being the first to get this out. I've been waiting for exactly that combination of technology ... using a phone's built-in gyro to do head-tracking and offer binaural decodes of ambisonic material on something we all carry around ... smart phones. If this combination of technology is not the future of ambisonics then I dont think anything is! Can I ask ... what is the latency on the head-tracking? Etienne On Wed, Dec 11, 2013 at 2:25 AM, Hector Centeno hcen...@gmail.com wrote: Hello all, I just wanted to share with this list information about two Android apps I've been working on and that I will release soon. I made them because I thought it would be great to be able to listen to ambisonic recordings in a portable way without the need of a full size computer. The first app is called AmbiExplorer and it's a first order decoder to stereo, with the option of choosing binaural or virtual microphones. You can peform soundfield rotation and microphone polar patten selection. It will also work with the device's orientation sensors so you could attach your device to headphones and have head-tracked binaural listening. The second app is called TetraFile and it's a port of the offline command line utility part of Fons' TetraProc. I made this so I could connect my portable recorder (in card reader mode) directly to my phone via USB OTG, transfer the A-format files and do a conversion to B-format and listen using AmbiExplorer. It will read your tetrafile calibration files from your phone's storage. More info and a video demo are available here: http://hcenteno.net/software.html Any comments are welcome. Best, Hector Centeno ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound -- http://etiennedeleflie.net ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
etienne deleflie wrote: finally! congratulations on being the first to get this out. I've been waiting for exactly that combination of technology ... using a phone's built-in gyro to do head-tracking and offer binaural decodes of ambisonic material on something we all carry around ... smart phones. Well, I didn't think that anyone would take a recent joke so seriously: to fix a phone at/on your head. But this is a great technology demonstration, so I will start to take my own joke a bit more serious. From now on... :-) The first app is called AmbiExplorer and it's a first order decoder to stereo, with the option of choosing binaural or virtual microphones. You can peform soundfield rotation and microphone polar patten selection. It will also work with the device's orientation sensors so you could attach your device to headphones and have head-tracked binaural listening. The first part is overdue (and many thanks to Hector!), the second part is a nice demonstration. But from a CE perspective, I highly doubt that normal consumers would glue (in my terms) their smartphone to their head. This is why I am stunned that no known headphone manufacturer is using any of all these widely available and really viable motion-tracking/gyroscope chips, by now. And: Things could be done in such an easier manner than ever before, by now: http://www.smyth-research.com/technology.html The Realiser system includes a small device atop the headphone headband and another small device at the front of the room, which together monitor the position of the listener's head every five milliseconds. (Bayer Headzone is similar and overcomplicated, from a current perspective. http://www.beyerdynamic.de/shop/headzone-headphone-surround-system.html You won't need any base station for HT, by now!) You can replace both former solutions with available motion tracking ICs. 200 Hz is no problem by now. (The Oculus Rift people give some specifications. I already wrote about this, some time ago. ) Beside of this, I have written so often about the Wii control, iPhone sensors, Glass motion sensors and Oculus Rift before that I seem entitled to utter my private opinion. See also my recent posting of the person who 3D-printed a frame for a smartphone as stereo display system for a 3D glass. (VR systems need HT and fast visual updates. We are all in-favour of head-tracked 5.1/Ambisonics decoding, so to speak) Many thanks to Hector Centeno, anyway. ( It has become way too obvious that any current developments in audio technology happen at an incredibly slow pace, compared to probably any other area. This is probably also partially my own fault, just writing about possible solutions and not actually doing them, cos I have a full-time job and life... :-D I also would not blame the music or audiophile industries, which don't know a lot about such complicated topics like technology or music... On a more positive note, Hector has written some of these apps for mobile devices which people (consumers) might actually use in tough real-world/daily life conditions! This wasn't about the usual Linux environment for connaisseurs, although some other people might object that these apps would even not exist without Linux... Maybe this was not the topic we should discuss! O:-) ) Best, Stefan Schreiber If this combination of technology is not the future of ambisonics then I dont think anything is! Can I ask ... what is the latency on the head-tracking? Etienne On Wed, Dec 11, 2013 at 2:25 AM, Hector Centeno hcen...@gmail.com wrote: Hello all, I just wanted to share with this list information about two Android apps I've been working on and that I will release soon. I made them because I thought it would be great to be able to listen to ambisonic recordings in a portable way without the need of a full size computer. The first app is called AmbiExplorer and it's a first order decoder to stereo, with the option of choosing binaural or virtual microphones. You can peform soundfield rotation and microphone polar patten selection. It will also work with the device's orientation sensors so you could attach your device to headphones and have head-tracked binaural listening. The second app is called TetraFile and it's a port of the offline command line utility part of Fons' TetraProc. I made this so I could connect my portable recorder (in card reader mode) directly to my phone via USB OTG, transfer the A-format files and do a conversion to B-format and listen using AmbiExplorer. It will read your tetrafile calibration files from your phone's storage. More info and a video demo are available here: http://hcenteno.net/software.html Any comments are welcome. Best, Hector Centeno ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
[Sursound] Upcoming Android apps ambisonic related
Hello all, I just wanted to share with this list information about two Android apps I've been working on and that I will release soon. I made them because I thought it would be great to be able to listen to ambisonic recordings in a portable way without the need of a full size computer. The first app is called AmbiExplorer and it's a first order decoder to stereo, with the option of choosing binaural or virtual microphones. You can peform soundfield rotation and microphone polar patten selection. It will also work with the device's orientation sensors so you could attach your device to headphones and have head-tracked binaural listening. The second app is called TetraFile and it's a port of the offline command line utility part of Fons' TetraProc. I made this so I could connect my portable recorder (in card reader mode) directly to my phone via USB OTG, transfer the A-format files and do a conversion to B-format and listen using AmbiExplorer. It will read your tetrafile calibration files from your phone's storage. More info and a video demo are available here: http://hcenteno.net/software.html Any comments are welcome. Best, Hector Centeno ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
Great - Hope we can get them to christmas :-) They will certainly be available before I have gotten together the remote sensor head control sensors... Is is a big difference between android and linux apps ? ( Android is a linux with other libraries) could you give us the Ambiexplorer for linux as a vst with control of directions via parameters. - Bo-Erik Sandholm Stockholm -Original Message- From: Sursound [mailto:sursound-boun...@music.vt.edu] On Behalf Of Hector Centeno Sent: den 10 december 2013 16:25 To: sursound@music.vt.edu Subject: [Sursound] Upcoming Android apps ambisonic related Hello all, I just wanted to share with this list information about two Android apps I've been working on and that I will release soon. I made them because I thought it would be great to be able to listen to ambisonic recordings in a portable way without the need of a full size computer. The first app is called AmbiExplorer and it's a first order decoder to stereo, with the option of choosing binaural or virtual microphones. You can peform soundfield rotation and microphone polar patten selection. It will also work with the device's orientation sensors so you could attach your device to headphones and have head-tracked binaural listening. The second app is called TetraFile and it's a port of the offline command line utility part of Fons' TetraProc. I made this so I could connect my portable recorder (in card reader mode) directly to my phone via USB OTG, transfer the A-format files and do a conversion to B-format and listen using AmbiExplorer. It will read your tetrafile calibration files from your phone's storage. More info and a video demo are available here: http://hcenteno.net/software.html Any comments are welcome. Best, Hector Centeno ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
Hector: What an incredible demonstration video! Isn't that John Leonard's wonderful recording of the Orfeo string quartet doing Beethoven? Third movement. If I recall correctly it was done with a TetraMic and a Metric Halo ULN-8. I can't wait to try your apps! Len Moskowitz (mosko...@core-sound.com) Core Sound LLC www.core-sound.com Home of TetraMic ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Upcoming Android apps ambisonic related
Hello Bo-Erik! Yes, I hope to have them released before Christmas. Making a VST out of the AmbiExplorer app would mean reprogramming most of it because even though Android is built on top of Linux, apps use lots of Android system specific frameworks. There's also the fact that it's mostly programmed in Java (not sure if there's an easy way of making audio plugins in Java) and for a plugin I would more likely want to use C++. I might anyways consider to work on it in the near future, though! Some of the work I've done for this app would definitively help towards programming a VST version. Cheers, Hector On Tue, Dec 10, 2013 at 10:55 AM, Bo-Erik Sandholm bo-erik.sandh...@ericsson.com wrote: Great - Hope we can get them to christmas :-) They will certainly be available before I have gotten together the remote sensor head control sensors... Is is a big difference between android and linux apps ? ( Android is a linux with other libraries) could you give us the Ambiexplorer for linux as a vst with control of directions via parameters. - Bo-Erik Sandholm Stockholm -Original Message- From: Sursound [mailto:sursound-boun...@music.vt.edu] On Behalf Of Hector Centeno Sent: den 10 december 2013 16:25 To: sursound@music.vt.edu Subject: [Sursound] Upcoming Android apps ambisonic related Hello all, I just wanted to share with this list information about two Android apps I've been working on and that I will release soon. I made them because I thought it would be great to be able to listen to ambisonic recordings in a portable way without the need of a full size computer. The first app is called AmbiExplorer and it's a first order decoder to stereo, with the option of choosing binaural or virtual microphones. You can peform soundfield rotation and microphone polar patten selection. It will also work with the device's orientation sensors so you could attach your device to headphones and have head-tracked binaural listening. The second app is called TetraFile and it's a port of the offline command line utility part of Fons' TetraProc. I made this so I could connect my portable recorder (in card reader mode) directly to my phone via USB OTG, transfer the A-format files and do a conversion to B-format and listen using AmbiExplorer. It will read your tetrafile calibration files from your phone's storage. More info and a video demo are available here: http://hcenteno.net/software.html Any comments are welcome. Best, Hector Centeno ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
