Re: [Sursound] Ambisonic-Binaural piece using Brahma mic (was Re: Great responses to my post--thanks!)
On Thu, Jan 12, 2012 at 06:52:14PM -0500, Hector Centeno wrote: Thank you Fons for your comments. What parameters did use for zita-bls1? The default ones? Yes. As to everything appearing in the back that's probably just me... I guess I could use a different HRTF measurement to avoid the front/back reversal. IRCAM's Spat comes with other impulse SDIF files that are 44.1kHz only so I wonder if anyone knows how to resample them to 48kHz, which is what I use. I always wondered why 44.1 kHz is so popular with EA music people... It's generally a pain if your whole studio uses 48 kHz as the standard. Are the IRs actually those from Ircam's LISTEN database ? These are all 44.1 kHz. I've started writing a small zita-convolver app to use them. This will resample as required but it's unfinished ATM. Ciao, -- FA ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Motivation for authors(Robert's off topic rant!)
Just turning things over in the back of my mind. Eric was pointing out that, without the peer review that goes with publication in a prestigious journal, a paper isn't taken seriously. as Robert points out, peer review offers at least some assurance that a paper does not contain 'junk information'. But, given that we don't get paid for reviewing, and reviewing standards vary considerably across publications (so we can't quite be sure of those assurances unless a particular journal is highly prestigious particularly for its rigour), is there another way? On the question of publishing but not preaching to the converted, one could see that some kind of peer review might help. I'm thinking that specialised publishing from leaders in the field, but pitching at the early-undergrad /bright-and-interested 6th former (in the Uk - that's a 17 year old; not sure of equivalents elsewhere)/ New Scientist reader would be of great benefit. Apart from anything else, it would provide good introductory teaching material, open source. I know all this openness puts the wind up those whose business model requires that information should be constrained (such as journals and universities), but it could be used to drive up the level of debate. One could see how discussion papers and erudite responses (which also need some kind of review process) could be quite illuminating. It still needs some kind of editorial function, I think, to keep up standards and to minimise 'noise' In the area of 3-d sound and spatial hearing, I would think this list is where one would look first regards 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-boun...@music.vt.edu [sursound-boun...@music.vt.edu] On Behalf Of Robert Greene [gre...@math.ucla.edu] Sent: 12 January 2012 06:15 To: Eric Carmichel; Surround Sound discussion group Subject: Re: [Sursound] Motivation for authors(Robert's off topic rant!) Scientific literature ought to be free or at least sold at the cost of its distribution. Publishers in the science field for profit are like zombies--they are dead but they are still walking around. There is a law about to be introduced in the California Legislature that will require courses in state universities to use open access textbooks(whenever possible). This is an admirable trend. Textbook publishing has become a scam, and so has journal publishing to a remarkable extent. They charge in many cases what the traffic will bear. I say this having written several book published in the old way and a whole lot of regular journal articles in journals with high subscription rates, over the years. That was the old way. But it is about to end, and good riddance to my mind. Some books cost money to make. If you want a beautiful art book, expect to pay for it. But there is no excuse for a calculus textbook to cost anything much, and even less excuse for old journal articles to cost anything at all. If it is in a library, it ought to be free on line unless it is new production(it does cost something to run a peer reviewed journal, but it costs a lot less than publishers tend to charge. And I know because I am an editor of a journal--and a good one--that publishes things at cost, a nonprofit but successful operation. Our subscription rate is a fraction of the commercial scientific journal rates--but our journal is just as good, has the same kind of refereeing processes and the same kind of referees, etc.) The on line revolution may not be all good--there is a lot of junk information on the web and it is not always easy for people to figure out that it is junk, but it will be good for science in the long run. It is ALREADY being good for science. Check out Project Euclid to see what I mean http://projecteuclid.org/DPubS?Service=UIversion=1.0verb=Displayhandle=euclidpage=browse Not everything there is open access so far--far from it. But soon it will be because competition will make it so. And this can be made to happen by the authors. Boycott sending your stuff to journals that do not have open access or at least cheap subscription rates. What conceivable excuse is there for anyone to be making a profit on the distribution of scientific information? None at all. Robert On Wed, 11 Jan 2012, Eric Carmichel wrote: Hello Fons, Your query (what motivates authors to make their work available in this way) made me think of my own situation. Perhaps publishing in peer-reviewed journals is analogous to receiving Merit Badges in Scouts: In some instances, it?s how one gets rated, noticed, or makes it to the next level. It seems (at least in the U.S.) that professors are pressured to publish in professional journals. As this applies to me, I was told (as a Master?s student) that I?d need at least a few peer-reviewed articles under my belt in order to get into a doctoral
Re: [Sursound] Motivation for authors(Robert's off topic rant!)
Just turning things over in the back of my mind. Eric was pointing out that, without the peer review that goes with publication in a prestigious journal, a paper isn't taken seriously. as Robert points out, peer review offers at least some assurance that a paper does not contain 'junk information'. Don't disagree on the merits of peer review. On the downside, though it can just end up as an example of GB Shaw's all professions are conspiracies against the public (or whatever he said). It can get stupid: One card carrying reviewer wanted 'rejection unless rewritten' because in a low level piece on legal risks I had said something like 'you could get sued like Mrs Smith (Daily Mirror, 1966, etc.) as it was not a peer reviewed _reference_ ... what did she want the All England Law Reports (also not p-r)? But, given that we don't get paid for reviewing, and reviewing standards vary considerably across publications (so we can't quite be sure of those assurances unless a particular journal is highly prestigious particularly for its rigour), is there another way? Citation indices aren't bad. (Or weren't till Google patented them ... ;-) (Though hilarious junk science gets over-cited, if only to contradict it.) On the question of publishing but not preaching to the converted, one could see that some kind of peer review might help. I'm thinking that specialised publishing from leaders in the field, but pitching at the early-undergrad /bright-and-interested 6th former (in the Uk - that's a 17 year old; not sure of equivalents elsewhere)/ New Scientist reader would be of great benefit. Apart from anything else, it would provide good introductory teaching material, open source. I know all this openness puts the wind up those whose business model requires that information should be constrained (such as journals and universities), but it could be used to drive up the level of debate. Is there still a level? I was recently asked to review an e-learning resource for undergrad biologists (more for the e-learning than content). I queried why science undergrad's need such a resource for what was first and second year college (11-13 y.o.) chemistry ... to be assured that that _was_ the level now. On your specific point: Reviews are excellent and under-published. IMHO all doctoral students should write and publish one in their early year(s) ... but I doubt if there are that many openings to publish them(?). So not disagreeing ... and your ideas are interesting, Peter. Just sceptical ... Regards, Michael One could see how discussion papers and erudite responses (which also need some kind of review process) could be quite illuminating. It still needs some kind of editorial function, I think, to keep up standards and to minimise 'noise' In the area of 3-d sound and spatial hearing, I would think this list is where one would look first regards 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 ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Ambisonic-Binaural piece using Brahma mic (was Re: Great responses to my post--thanks!)
Le 13 janv. 2012 à 00:52, Hector Centeno a écrit : I guess I could use a different HRTF measurement to avoid the front/back reversal. IRCAM's Spat comes with other impulse SDIF files that are 44.1kHz only so I wonder if anyone knows how to resample them to 48kHz, which is what I use. 48kHz filters for Spat : http://echanges.ircam.fr/filez/download.php?ad=239605ZfpX I do interpolate separately the excess phase part and the magnitude spectrum, rather than resampling the HRIR. -- next part -- An HTML attachment was scrubbed... URL: https://mail.music.vt.edu/mailman/private/sursound/attachments/20120113/6ec6fbd6/attachment.html ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Ambisonic-Binaural piece using Brahma mic (was Re: Great responses to my post--thanks!)
Hi Thibaut, Is there a specific technical reason for doing it that way, or is it just more convenient? Dave On 13 January 2012 12:47, Thibaut Carpentier thibaut.carpent...@ircam.frwrote: I do interpolate separately the excess phase part and the magnitude spectrum, rather than resampling the HRIR. -- next part -- An HTML attachment was scrubbed... URL: https://mail.music.vt.edu/mailman/private/sursound/attachments/20120113/6ec6fbd6/attachment.html ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound -- These are my own views and may or may not be shared by my employer Dave Malham http://music.york.ac.uk/staff/research/dave-malham/%20 Music Research Centre Department of Music The University of York Heslington York YO10 5DD UK Phone 01904 322448 Fax 01904 322450 'Ambisonics - Component Imaging for Audio' http://www.york.ac.uk/inst/mustech/3d_audio/ -- next part -- An HTML attachment was scrubbed... URL: https://mail.music.vt.edu/mailman/private/sursound/attachments/20120113/1b37eb5f/attachment.html ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Ambisonic-Binaural piece using Brahma mic (was Re: Great responses to my post--thanks!)
Thank you Thibaut, I've been looking for these for long time! I couldn't find them easily in the IRCAM website. Cheers, Hector On 2012-01-13, at 7:47 AM, Thibaut Carpentier wrote: Le 13 janv. 2012 à 00:52, Hector Centeno a écrit : I guess I could use a different HRTF measurement to avoid the front/back reversal. IRCAM's Spat comes with other impulse SDIF files that are 44.1kHz only so I wonder if anyone knows how to resample them to 48kHz, which is what I use. 48kHz filters for Spat : http://echanges.ircam.fr/filez/download.php?ad=239605ZfpX I do interpolate separately the excess phase part and the magnitude spectrum, rather than resampling the HRIR. -- next part -- An HTML attachment was scrubbed... URL: https://mail.music.vt.edu/mailman/private/sursound/attachments/20120113/6ec6fbd6/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] Motivation for authors(Robert's off topic rant!)
Peter Lennox p.len...@derby.ac.uk wrote: ... On the question of publishing but not preaching to the converted, one could see that some kind of peer review might help. I'm thinking that specialised publishing from leaders in the field, but pitching at the early-undergrad /bright-and-interested 6th former (in the Uk - that's a 17 year old; not sure of equivalents elsewhere)/ New Scientist reader would be of great benefit. This could be published in New Scientist. Mind you, as it published Zuccarelli's Holophonics then it will publish anything. Regards, Martin -- Martin J Leese E-mail: martin.leese stanfordalumni.org Web: http://members.tripod.com/martin_leese/ ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Ambisonic-Binaural piece using Brahma mic (was Re: Great responses to my post--thanks!)
... so I tested loading these 48kHz filters but I get a Invalid header error in Max/MSP when trying the HRTF files. The coll files work fine. Is there any mayor difference between the two that I might be missing? I used a hex editor to inspect the header and compared it with a 44.1 file and found that indeed there is different info there. Are these for a recent version of Spat? Mine is from 2010. Hector On 2012-01-13, at 12:50 PM, Hector Centeno wrote: Thank you Thibaut, I've been looking for these for long time! I couldn't find them easily in the IRCAM website. Cheers, Hector On 2012-01-13, at 7:47 AM, Thibaut Carpentier wrote: Le 13 janv. 2012 à 00:52, Hector Centeno a écrit : I guess I could use a different HRTF measurement to avoid the front/back reversal. IRCAM's Spat comes with other impulse SDIF files that are 44.1kHz only so I wonder if anyone knows how to resample them to 48kHz, which is what I use. 48kHz filters for Spat : http://echanges.ircam.fr/filez/download.php?ad=239605ZfpX I do interpolate separately the excess phase part and the magnitude spectrum, rather than resampling the HRIR. -- next part -- An HTML attachment was scrubbed... URL: https://mail.music.vt.edu/mailman/private/sursound/attachments/20120113/6ec6fbd6/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
[Sursound] Rearward, march! (RE binaural listening rearward illusions)
Hi Dave, I just wished to add my two bits regarding binaural listening and the rearward illusion you experience. Having investigated the effects of binaural electronic hearing protectors on localization, I do recall two sources of information (in addition to my own) where listeners experienced a rearward illusion of sound sources. The studies had to do with hearing protection devices (HPDs), but aspects of the studies apply to binaural listening in general. Of course, retaining head and pinna cues is what we desire with binaural recordings, but one man’s HRTF is another man’s, well...? In one of the (HPD) studies, pinna cues were absent because of occlusion, and this was believed to account for a rearward illusion. The references are Russell G, Noble WG. Localization response certainty in normal and disrupted listening conditions: Towards a new theory of localization. J Aud Res 1976; 16: 143-50 Oldfield SR, Parker SP. Acuity of sound localization: A topography of auditory space: II, Pinna cues absent. Perception 1984; 13: 601-17 For Russell and Noble, it was believed that loss of canal resonance accounted for a rearward illusion (this was for listeners wearing earplugs). Under earphones, things are different. For example: In my study*, it was easy for subjects’ to discern left-from-right sound source location but discrimination between left rear and left front (or right rear and right front) was difficult. Front-back reversals accounted for the largest percentage of errors. Most errors made for the HPD conditions occurred at 120 degrees and 240 degrees (rear plane) and sounds coming from these locations were often judged as coming from 60 and 300 degrees (front plane), respectively. One listener, however, made localization errors opposite from other listeners. For this listener, regardless of condition, more ipsilateral errors were made to sounds coming from 0 degrees than for sounds coming from 180 degrees. Localization under HPDs for this listener was also unique: Stimuli presented at 60 and 300 degrees were often judged to originate from 120 and 240 degrees, respectively, which was opposite from the other listeners. Why a frontal or rearward proclivity for any particular listener is a good question. But it does appear that it is consistent for a given person. For me, binaural recordings almost always seem to be in the head (despite everyone’s best efforts), but sounds will appear to be outside of my head if they’re to the extreme left or right and include the requisite cues (beyond ILDs). Results from my HPD study suggested that binaural electronic HPDs retain the ILD cue needed for lateralization (I carefully matched the gain between earcups). However, pinna-head cues needed to make accurate front/back judgments are not retained. According to Oldfield and Parker, such errors would be anticipated despite stereo sound provided by the HPDs because the ITD of sound at the tympanic membrane does not uniquely specify a location in space, only the left/right component. Incidentally, manufacturers’ statements for their respective binaural electronic HPDs included ‘True ‘stereo’ for directional sound detection’ ‘Stereo sound so much like your own hearing that you retain your natural sense of sound direction’ ‘…provides you with 360 degrees awareness of sound direction with the clearest sound amplification available’ Hmmm... Check out the following and see what at least one study revealed. *Noise Health, October-December 2007, Volume 9. I think it cost a bit to download; however, I won’t comment here on the cost of journal articles. If you’d like to see a PowerPoint regarding this study, you can download it from www.elcaudio.com/hearing/hpd_localization.pps [26.37 MB] I presented this study (and the PP) at a colloquium: Attendees included William (Bill) Yost and other noteworthy hearing scientists. Question: What if the same study was repeated only using an Ambisonic surround system? I wonder whether the same localization errors would occur. This, to some extent, might validate the usefulness of Ambisonics in hearing research. Another PP, for those interested in signal processing, otoacoustic emissions and hearing physiology (not too much psychoacoustics), can be downloaded from www.elcaudio.com/hearing/oae_study.pps [5.62 MB] (This study was kindly rejected by JASA, but it’s still in progress.) Kind regards, Eric C. -- next part -- An HTML attachment was scrubbed... URL: https://mail.music.vt.edu/mailman/private/sursound/attachments/20120113/c498bcad/attachment.html ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Rearward, march! (RE binaural listening rearward illusions)
/private/sursound/attachments/20120113/c498bcad/attachment.html ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.925 / Virus Database: 271.1.1/4139 - Release Date: 01/13/12 06:34:00 -- next part -- An HTML attachment was scrubbed... URL: https://mail.music.vt.edu/mailman/private/sursound/attachments/20120114/76aedf08/attachment.html ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
[Sursound] AAA (Ardour, Arduino, Ambisonics)
Hi Fons, Thanks for the info regarding Ardour. Although I’m not an application developer (nor aspire to be), I have used Python. Not too long back, I purchased some sensors from Phidget to make a response box. I also built a few gadgets based on the Arduino microcontroller, and Python code simplified a few of the interfacing tasks. I’m a proponent of ergonomic response boxes and generally design and build my own response boxes in lieu of off-the-shelf interface devices. If the control layout (generally push-button switches) isn’t intuitive to the user, then I would question whether response time could be valid, at least not without a lot of user training. (Measuring response time can be useful in many experiments). All switches/keys should be equally accessible, and there shouldn’t be any ambiguity as to what each switch represents. Using a standard keyboard is generally a compromise. Sometimes making an interface device ‘talk’ isn’t the only issue. For example, it’s difficult to route wires through a sound test booth if it isn’t pre-equipped with a patch bay/panel. One of my response boxes sends its signal along a single-conductor shielded cable (terminated with a BNC connector for ease of use). This response box used a pre-programmed microchip from a Velleman electronics kit: The design allowed me to send 15 discrete ON/OFF channels along the single-conductor cable which, in turn, was considerably easier to route than a multi-pin connector or multi-conductor cable would have allowed. Adding a patch panel or multi-conductor connector to the heavy steel walls of an audiometric test booth isn’t easy: I’ve had to do this (for others) in the past. In other instances, a subject’s safety has to be insured in order to obtain IRB approval for a study. Fiber optic communication comes in handy when grounding or electrical isolation is a concern. The downside of fiber optics is that a battery-operated response box (or preamplifier when electrodes are used) is needed, but this is just a minor inconvenience. But with the aforementioned single-conductor setup, DC power (along with the multiplexed signal) is sent along the wire, and one need not worry about battery life. Regardless of user-interface / hardware, talking with the computer is the next step. Having open source software (and Arduino hardware) has certainly made life easier for the experimenter. Once I get my Linux rig together, I’ll look into the possibilities offered. I make no claims as to being software or computer savvy, but I generally find a creative solution (or an adept person) to get things rolling. I’ll let you know how things progress with my Ambisonic setup as well as future hearing experiment(s). Kind regards, Eric C. PS—Maybe I should have titled this (Adriaensen, Ardour, Arduino, Ambisonics)? -- next part -- An HTML attachment was scrubbed... URL: https://mail.music.vt.edu/mailman/private/sursound/attachments/20120113/6fb17e16/attachment.html ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
