Subject: Re: [AUDITORY] On 3D audio rendering for signals with the low sampling frequency From: Adam Weisser <adam_weisser@xxxxxxxx> Date: Thu, 18 Aug 2022 20:43:08 -0300--e8241ae01caf4c8cbec974da67cc371a Content-Type: text/plain;charset=utf-8 Content-Transfer-Encoding: quoted-printable Dear John and all, In the task you've referred to I aimed to obtain the individual threshol= d of discriminating between fast sequences of two or three Gabor pulses = centered at 6 kHz. This in turn was converted to a bounded estimate of t= he instantaneous sampling rate that was hypothetically necessary to achi= eve this result, assuming that the auditory system samples the stimulus = and is not immune from (instantaneous) aliasing (i.e., it does not have = an anti-aliasing filter equivalent). However, I tested only 10 normal-he= aring people (PTA<20 dB HL) and no hearing-impaired participants. But I = should note that the entire experiment should be replicated at some poin= t with more test points and better blocking. With this caveat in mind, I= can only offer an anecdotal observation about the threshold-in-noise te= st variation.=20 In the normal variation of the test, the best performing listeners had t= hresholds that were very similar to other temporal acuity tests (2-4 ms)= , such as gap detection, whereas other subjects achieved much worse (lon= ger) thresholds (up to 20-35 ms). When notched-broadband noise was added= to mask the off-frequency channels, the results were split to two clust= ers. The thresholds of four subjects, including the three youngest parti= cipants (< 25 years old), did not change as a result of the noise, regar= dless of their baseline threshold. The thresholds of the other six subje= cts significantly deteriorated, also regardless of their individual base= line. Some of the subjects in the latter group self-reported difficultie= s of hearing speech in noise, whereas none of the four "high-performing"= subjects reported any such difficulty. I found it all very curious at t= he time, but did not have much data to work with to draw any conclusions= .=20 Incidentally, the split in the subject group is not unlike the pattern t= hat is reported in informational-masking studies, where only a subset of= the normal-hearing subjects are sensitive to off-frequency tonal masker= s (e.g., Neff, Dethles, Jesteadt, 1993). All the best, Adam. On Wed, Aug 17, 2022, at 5:57 AM, Beerends, J.G. (John) wrote: > Hi Chris, Adam, All, > =20 > Should this effect of dense sampling at the onset have a practical con= sequence of assessing hearing loss also with a 2 / 3 pulse discriminatio= n task? > I am not aware that such test are used or being developed. > (this idea was inspired by Appendix E of Adams book Weisser, A. (2021)= . Treatise on Hearing: The Temporal Auditory Imaging Theory Inspired by = Optics and Communication. <https://arxiv.org/abs/2111.04338>*arXiv prep= rint arXiv:2111.04338 <https://arxiv.org/abs/2111.04338>*. <https://arxi= v.org/abs/2111.04338> > ) > =20 > Regards, > John Beerends > http://beesikk.nl/JohnBeerends.htm > =20 > *From:* AUDITORY - Research in Auditory Perception <AUDITORY@xxxxxxxx= ILL.CA> *On Behalf Of *Chris Stecker > *Sent:* dinsdag 16 augustus 2022 20:16 > *To:* AUDITORY@xxxxxxxx > *Subject:* Re: On 3D audio rendering for signals with the low sampling= frequency > =20 > Hi all, Particularly Leslie and Adam: > =20 > =20 > The ready availability of binaural information at sound onsets and oth= er positive fluctuations of the amplitude envelope is well supported by = decades of psychophysical evidence, including 20 years of my own publica= tions. The overall evidence, and the theory which it motivates (=E2=80=9C= RESTART theory=E2=80=9D) is reviewed in a 2020 chapter of the Springer H= andbook on Auditory Research by myself, Les Bernstein, and Andrew Brown: > =20 > *Stecker, G. C.,* Bernstein, L. R., and Brown, A. D. (*2020*). Binaura= l hearing with temporally complex signals. Chapter 5 in Goupell, M. J., = Litovsky, R. Y, Popper, A. N., and Fay, R. R. (eds). *Springer Handbook = of Auditory Research Vol 73: Binaural Hearing*. Switzerland: Springer In= ternational. doi:10.1007/978-3-030-57100-9=20 > =20 > Please contact me if you need help accessing the chapter.=20 > =20 > In quick summary, the evidence suggests that all forms of binaural cue= (ITD of the envelope and fine structure, ILD, etc) available at any coc= hlear place (i.e. frequency) are specifically =E2=80=9Csampled=E2=80=9D = at moments of positive envelope fluctuation. As Adam suggests, one obvio= us source of this =E2=80=9Csampling=E2=80=9D process is the strong adapt= ation exhibited in neural pathways prior to binaural interaction (e.g. h= air cells, AN fibers, various cells of the cochlear nucleus). Indeed, ph= enomenological models that include realistic adaptive behavior exhibit m= any of the same properties observed psychophysically (Stecker 2020, Asso= c Res Otolaryngol Abs 43).=20 > =20 > A feature of the data which is sometimes overlooked is the apparent re= fractory nature of this =E2=80=9Csampling=E2=80=9D process. New samples,= or =E2=80=9Consets=E2=80=9D can occur in succession, but not much more = quickly than 200-300 times per second (3-5 ms). Above that rate (e.g. fo= r rapid paired pulses, =E2=80=9Csteady=E2=80=9D tones, etc.) binaural pr= ocessing is confined to the overall onset. This rate limitation itself d= efines what counts as an =E2=80=9Conset=E2=80=9D for binaural processing= : below the critical rate, successive events each contribute roughly equ= ally and independently to spatial perception.=20 > =20 > What does this have to do with spatial cue representation at low sampl= ing rates? Many of the mentions in this thread quite rightly invoke line= ar systems theory to understand the consequences of limiting bandwidth (= i.e. due to slow sampling) on these representations. Various tricks may = be suggested to somewhat extend the effective bandwidth (e.g. non-unifor= m sampling, etc.). I don=E2=80=99t have much to add there, except to con= sider how the brain might do it.=20 > =20 > In my view, it is important to keep in mind that no mechanisms of the = ear or brain are, in fact, linear. Neuronal adaptation is highly nonline= ar and also temporally asymmetric. A consequence is dramatic over-repres= entation of rapid onset-like events=E2=80=93events that, in a linear sys= tem, would imply very broad bandwidth. Thus, auditory =E2=80=9Cchannels=E2= =80=9D are capable of representations that apparently exceed the narrow = "bandwidth=E2=80=9D implied by their cochlear-place selectivity. That no= tion seems absurd on its face, because many of us have been trained to t= hink about auditory function as "quasi-linear=E2=80=9D (e.g. using terms= like =E2=80=9Cauditory filter=E2=80=9D to refer to neural pathways that= are clearly not filters). But in fact it should not be surprising based= on the actual physiology.=20 > =20 > This has clear consequences for loads of phenomena in binaural and spa= tial hearing: precedence, binaural adaptation, jitter in CI pulse timing= , =E2=80=9Cstraightness=E2=80=9D, etc. (Stecker, Dietz, and Stern 2019(A= ), JASA 145:1759).=20 > =20 > Thank you for your attention, and for the interesting discussion!=20 > =20 > -Chris > =20 > =20 > =20 >=20 > =E2=80=94 > =20 > G. Christopher Stecker, Ph.D., F.A.S.A. > =20 > Director, Spatial Hearing Lab > Director, Research Technology > Boys Town National Research Hospital > =20 > Coordinating Editor, Psychological and Physiological Acoustics > Journal of the Acoustical Society of America > =20 > =20 > cstecker@xxxxxxxx > www.spatialhearing.org > =20 > =20 > =20 > =20 > =20 > =20 > =20 > =20 >> On Aug 15, 2022, at 3:23 AM, Prof Leslie Smith <l.s.smith@xxxxxxxx= UK> wrote: >> =20 >>=20 >> Dear all: >>=20 >> Some years ago, I worked on using sound at onsets for calculating sou= rce >> direction in reverberant environments [1]. It's kind-of obvious, beca= use >> after the onset, the sound at the ear/microphone is made up of energy= both >> from the source and from reflections. >>=20 >> Sampling rates are normally constant, and techniques for compression = are >> aimed at recreating the percept of the original sound: I am under the >> impression that this doesn't extend to the percept of precise locatio= n of >> the sound. Perhaps we need novel compression/decompression techniques >> that include the relevant data for source location. >>=20 >> [1] L.S. Smith, S. Collins Determining ITDs using two microphones on a >> flat panel during onset intervals with a biologically inspired spike = based >> technique >> IEEE Transactions of Audio, Speech and Language Processing, 15, 8, >> 2278-2286, (2007). >>=20 >> --Leslie Smith >>=20 >> Adam Weisser wrote: >>=20 >>=20 >>=20 >>=20 >>>=20 >>> 1. Compressed sensing - This heavily researched signal-processing me= thod >>> uses signal sparsity to faithfully reconstruct undersampled signals = [1]. >>>=20 >>>=20 >>=20 >> ..... >>=20 >>=20 >>=20 >>>=20 >>> Neural adaptation can be thought of as dense >>> sampling of the signal around its onset / transient portion, which b= ecomes >>> more sparsely sampled quickly after the onset. Because of adaptation= , this >>> effect is very illusive, but I believe that it is measurable >>> notwithstanding. I tried to demonstrate it psychoacoustically in App= endix >>> E of [4]. While I don't know how it relates to binaural processing >>> directly, there may be instantaneous effects that may be detectable = there >>> too, given that the input to both processing types is the same. >>>=20 >>> All the best, >>> Adam. >>>=20 >>>=20 >>=20 >> ... >>=20 >>=20 >> --=20 >> Prof Leslie Smith (Emeritus) >> Computing Science & Mathematics, >> University of Stirling, Stirling FK9 4LA >> Scotland, UK >> Tel +44 1786 467435 >> Web: http://www.cs.stir.ac.uk/~lss >> Blog: http://lestheprof.com >>=20 >>=20 > =20 > =20 >=20 > This message may contain information that is not intended for you. If = you are not the addressee or if this message was sent to you by mistake,= you are requested to inform the sender and delete the message. TNO acce= pts no liability for the content of this e-mail, for the manner in which= you use it and for damage of any kind resulting from the risks inherent= to the electronic transmission of messages. --e8241ae01caf4c8cbec974da67cc371a Content-Type: text/html;charset=utf-8 Content-Transfer-Encoding: quoted-printable <!DOCTYPE html><html><head><title></title><style type=3D"text/css">#qt p= .qt-MsoNormal{margin-top:0cm;margin-right:0cm;margin-bottom:0cm;margin-l= eft:0cm;font-size:11pt;font-family:"Calibri", sans-serif;} #qt a:link{color:blue;text-decoration-line:underline;text-decoration-sty= le:solid;text-decoration-color:currentcolor;text-decoration-thickness:au= to;} p.MsoNormal,p.MsoNoSpacing{margin:0}</style></head><body><div style=3D"f= ont-family:Arial;">Dear John and all,<br></div><div style=3D"font-family= :Arial;"><br></div><div style=3D"font-family:Arial;">In the task you've = referred to I aimed to obtain the individual threshold of discriminating= between fast sequences of two or three Gabor pulses centered at 6 kHz. = This in turn was converted to a bounded estimate of the instantaneous sa= mpling rate that was hypothetically necessary to achieve this result, as= suming that the auditory system samples the stimulus and is not immune f= rom (instantaneous) aliasing (i.e., it does not have an anti-aliasing fi= lter equivalent). However, I tested only 10 normal-hearing people (PTA&l= t;20 dB HL) and no hearing-impaired participants. But I should note that= the entire experiment should be replicated at some point with more test= points and better blocking. With this caveat in mind, I can only offer = an anecdotal observation about the threshold-in-noise test variation. <b= r></div><div style=3D"font-family:Arial;"><br></div><div style=3D"font-f= amily:Arial;">In the normal variation of the test, the best performing l= isteners had thresholds that were very similar to other temporal acuity = tests (2-4 ms), such as gap detection, whereas other subjects achieved m= uch worse (longer) thresholds (up to 20-35 ms). When notched-broadband n= oise was added to mask the off-frequency channels, the results were spli= t to two clusters. The thresholds of four subjects, including the three = youngest participants (< 25 years old), did not change as a result of= the noise, regardless of their baseline threshold. The thresholds of th= e other six subjects significantly deteriorated, also regardless of thei= r individual baseline. Some of the subjects in the latter group self-rep= orted difficulties of hearing speech in noise, whereas none of the four = "high-performing" subjects reported any such difficulty. I found it= all very curious at the time, but did not have much data to work with t= o draw any conclusions. <br></div><div style=3D"font-family:Arial;"= ><br></div><div style=3D"font-family:Arial;">Incidentally, the split in = the subject group is not unlike the pattern that is reported in informat= ional-masking studies, where only a subset of the normal-hearing subject= s are sensitive to off-frequency tonal maskers (e.g., Neff, Dethles, Jes= teadt, 1993).<br></div><div style=3D"font-family:Arial;"><br></div><div = style=3D"font-family:Arial;">All the best,<br></div><div style=3D"font-f= amily:Arial;">Adam.<br></div><div style=3D"font-family:Arial;"><br></div= ><div>On Wed, Aug 17, 2022, at 5:57 AM, Beerends, J.G. (John) wrote:<br>= </div><blockquote type=3D"cite" id=3D"qt" style=3D"overflow-wrap:break-w= ord;"><div class=3D"qt-WordSection1"><p class=3D"qt-MsoNormal"><span sty= le=3D"">Hi Chris, Adam, All,</span><br></p><p class=3D"qt-MsoNormal"><sp= an style=3D""> </span><br></p><p class=3D"qt-MsoNormal"><span style= =3D"" lang=3D"EN-US">Should this effect of dense sampling at the onset h= ave a practical consequence of assessing hearing loss also with a 2 / 3 = pulse discrimination task?</span><br></p><p class=3D"qt-MsoNormal"><span= style=3D"" lang=3D"EN-US">I am not aware that such test are used or bei= ng developed.</span><br></p><p class=3D"qt-MsoNormal"><span style=3D"" l= ang=3D"EN-US">(this idea was inspired by Appendix E of Adams book <span = class=3D"font" style=3D"font-family:"Arial", sans-serif;"><a h= ref=3D"https://arxiv.org/abs/2111.04338"><span lang=3D"EN-US">Weisser, A= . (2021). Treatise on Hearing: The Temporal Auditory Imaging Theory Insp= ired by Optics and Communication. </span></a><i><a href=3D"https://arxiv.org/abs/2111.= 04338">arXiv preprint arXiv:2111.04338</a></i><a href=3D"https://arxiv.o= rg/abs/2111.04338">.</a></span></span><br></p><p class=3D"qt-MsoNormal">= <span style=3D""><span class=3D"font" style=3D"font-family:"Arial&q= uot;, sans-serif;">)</span></span><br></p><p class=3D"qt-MsoNormal"><spa= n style=3D"" lang=3D"EN-US"> </span><br></p><p class=3D"qt-MsoNorma= l"><span style=3D"" lang=3D"EN-US">Regards,</span><br></p><p class=3D"qt= -MsoNormal"><span style=3D"" lang=3D"EN-US">John Beerends</span><br></p>= <p class=3D"qt-MsoNormal"><span style=3D"" lang=3D"EN-US"><a href=3D"htt= p://beesikk.nl/JohnBeerends.htm">http://beesikk.nl/JohnBeerends.htm</a><= /span><br></p><p class=3D"qt-MsoNormal"><span style=3D"" lang=3D"EN-US">= </span><br></p><div><div style=3D"border-right-color:currentcolor;= border-right-style:none;border-right-width:medium;border-bottom-color:cu= rrentcolor;border-bottom-style:none;border-bottom-width:medium;border-le= ft-color:currentcolor;border-left-style:none;border-left-width:medium;bo= rder-image-outset:0;border-image-repeat:stretch;border-image-slice:100%;= border-image-source:none;border-image-width:1;border-top-color:rgb(225, = 225, 225);border-top-style:solid;border-top-width:1pt;padding-top:3pt;pa= dding-right:0cm;padding-bottom:0cm;padding-left:0cm;"><p class=3D"qt-Mso= Normal"><b><span lang=3D"EN-US">From:</span></b><span lang=3D"EN-US"> AU= DITORY - Research in Auditory Perception <AUDITORY@xxxxxxxx>= ; <b>On Behalf Of </b>Chris Stecker<br> <b>Sent:</b> dinsdag 16 augustus= 2022 20:16<br> <b>To:</b> AUDITORY@xxxxxxxx<br> <b>Subject:</b> = Re: On 3D audio rendering for signals with the low sampling frequency</s= pan></p></div></div><p class=3D"qt-MsoNormal"> <br></p><p class=3D"= qt-MsoNormal">Hi all, Particularly Leslie and Adam:<br></p><div><p class= =3D"qt-MsoNormal"> <br></p></div><div><p class=3D"qt-MsoNormal">&nb= sp;<br></p></div><div><p class=3D"qt-MsoNormal">The ready availability o= f binaural information at sound onsets and other positive fluctuations o= f the amplitude envelope is well supported by decades of psychophysical = evidence, including 20 years of my own publications. The overall evidenc= e, and the theory which it motivates (=E2=80=9CRESTART theory=E2=80=9D) is= reviewed in a 2020 chapter of the Springer Handbook on Auditory Researc= h by myself, Les Bernstein, and Andrew Brown:<br></p></div><div><p class= =3D"qt-MsoNormal"> <br></p></div><div><p class=3D"qt-MsoNormal"><b>= <span style=3D"" lang=3D"EN-US"><span class=3D"font" style=3D"font-famil= y:"Arial", sans-serif;"><span class=3D"size" style=3D"font-siz= e:10pt;">Stecker, G. C.,</span></span></span></b><span style=3D"" lang=3D= "EN-US"><span class=3D"font" style=3D"font-family:"Arial", san= s-serif;"><span class=3D"size" style=3D"font-size:10pt;"> Bernstein, L. R., and Brown, A. D. (<b>2020</b>). Binaural hearing with temporally= complex signals. Chapter 5 in Goupell, M. J., Litovsky, R. Y, Popper, A= . N., and Fay, R. R. (eds). <i>Springer Handbook of Auditory Research Vo= l 73: Binaural Hearing</i>. Switzerland: Springer International. doi:10.= 1007/978-3-030-57100-9 </span></span></span><br></p></div><div><p c= lass=3D"qt-MsoNormal"> <br></p></div><div><p class=3D"qt-MsoNormal"= ><span style=3D"" lang=3D"EN-US"><span class=3D"font" style=3D"font-fami= ly:"Arial", sans-serif;"><span class=3D"size" style=3D"font-si= ze:10pt;">Please contact me if you need help accessing the chapter. = ;</span></span></span><br></p></div><div><p class=3D"qt-MsoNormal"> = ;<br></p></div><div><p class=3D"qt-MsoNormal"><span style=3D""><span cla= ss=3D"font" style=3D"font-family:"Arial", sans-serif;"><span c= lass=3D"size" style=3D"font-size:10pt;">In quick summary, the evidence s= uggests that all forms of binaural cue (ITD of the envelope and fine str= ucture, ILD, etc) available at any cochlear place (i.e. frequency) are specifically =E2=80=9Csampled=E2=80=9D at moments of positive enve= lope fluctuation. As Adam suggests, one obvious source of this =E2=80= =9Csampling=E2=80=9D process is the strong adaptation exhibited in neura= l pathways prior to binaural interaction (e.g. hair cells, AN fiber= s, various cells of the cochlear nucleus). Indeed, phenomenological models that inc= lude realistic adaptive behavior exhibit many of the same properties obs= erved psychophysically </span><span class=3D"size" style=3D"font-si= ze:12pt;">(Stecker 2020, Assoc Res Otolaryngol Abs 43). </span></span></span><br></p></div><div><p class=3D"qt-Ms= oNormal"> <br></p></div><div><p class=3D"qt-MsoNormal"><span style=3D= ""><span class=3D"font" style=3D"font-family:"Arial", sans-ser= if;"><span class=3D"size" style=3D"font-size:10pt;">A feature of the dat= a which is sometimes overlooked is the apparent refractory nat= ure of this =E2=80=9Csampling=E2=80=9D process. New samples, or =E2= =80=9Consets=E2=80=9D can occur in succession, but not much more quickly than 200-300 times per second (3-5 ms). Above that rate (e= .g. for rapid paired pulses, =E2=80=9Csteady=E2=80=9D tones, etc.) binau= ral processing is confined to the overall onset. This rate limitati= on itself defines what counts as an =E2=80=9Conset=E2=80=9D fo= r binaural processing: below the critical rate, successive events each contribute roughly = ;equally and independently to spatial perception. </span></spa= n></span><br></p></div><div><p class=3D"qt-MsoNormal"> <br></p></di= v><div><p class=3D"qt-MsoNormal">What does this have to do with spatial = cue representation at low sampling rates? Many of the mentions in this t= hread quite rightly invoke linear systems theory to understand the conse= quences of limiting bandwidth (i.e. due to slow sampling) on these representations. Various tricks may be suggested to somewhat e= xtend the effective bandwidth (e.g. non-uniform sampling, etc.). I don=E2= =80=99t have much to add there, except to consider how the brain might d= o it. <br></p></div><div><p class=3D"qt-MsoNormal"> <br></p></= div><div><p class=3D"qt-MsoNormal">In my view, it is important to keep i= n mind that no mechanisms of the ear or brain are, in fact, linear. Neur= onal adaptation is highly nonlinear and also temporally asymmetric. A co= nsequence is dramatic over-representation of rapid onset-like events=E2=80=93events that, in a linear system, would imply very broad = bandwidth. Thus, auditory =E2=80=9Cchannels=E2=80=9D are capable of repr= esentations that apparently exceed the narrow "bandwidth=E2=80=9D implie= d by their cochlear-place selectivity. That notion seems absurd on its f= ace, because many of us have been trained to think about auditory function a= s "quasi-linear=E2=80=9D (e.g. using terms like =E2=80=9Cauditory filter= =E2=80=9D to refer to neural pathways that are clearly not filters). But= in fact it should not be surprising based on the actual physiology.&nbs= p;<br></p></div><div><p class=3D"qt-MsoNormal"> <br></p></div><div>= <p class=3D"qt-MsoNormal">This has clear consequences for loads of pheno= mena in binaural and spatial hearing: precedence, binaural adaptation, j= itter in CI pulse timing, =E2=80=9Cstraightness=E2=80=9D, etc. <spa= n style=3D""><span class=3D"font" style=3D"font-family:"Arial"= , sans-serif;"><span class=3D"size" style=3D"font-size:12pt;">(Stecker, Dietz, and Stern 2019(A), JASA 145:1759). </span></span></span><br= ></p></div><div><p class=3D"qt-MsoNormal"> <br></p></div><div><p cl= ass=3D"qt-MsoNormal">Thank you for your attention, and for the interesti= ng discussion! <br></p></div><div><p class=3D"qt-MsoNormal"> <= br></p></div><div><p class=3D"qt-MsoNormal">-Chris<br></p></div><div><p = class=3D"qt-MsoNormal"> <br></p></div><div><p class=3D"qt-MsoNormal= "> <br></p></div><div><p class=3D"qt-MsoNormal"> <br></p><div>= <div><div><div><div><div><div><div><div><p class=3D"qt-MsoNormal"><span = style=3D"color:black;"><span class=3D"font" style=3D"font-family:"H= elvetica", sans-serif;"><span class=3D"size" style=3D"font-size:9pt= ;"><br>=E2=80=94</span></span></span></p></div><div><p class=3D"qt-MsoNo= rmal"><span style=3D"color:black;"><span class=3D"font" style=3D"font-fa= mily:"Helvetica", sans-serif;"><span class=3D"size" style=3D"f= ont-size:9pt;"> </span></span></span><br></p></div><div><p class=3D= "qt-MsoNormal"><span style=3D"color:black;"><span class=3D"font" style=3D= "font-family:"Helvetica", sans-serif;"><span class=3D"size" st= yle=3D"font-size:9pt;">G. Christopher Stecker, Ph.D., F.A.S.A.</span></s= pan></span><br></p></div><div><p class=3D"qt-MsoNormal"><span style=3D"c= olor:black;"><span class=3D"font" style=3D"font-family:"Helvetica&q= uot;, sans-serif;"><span class=3D"size" style=3D"font-size:9pt;"> <= /span></span></span><br></p></div><div><p class=3D"qt-MsoNormal"><span s= tyle=3D"color:black;"><span class=3D"font" style=3D"font-family:"He= lvetica", sans-serif;"><span class=3D"size" style=3D"font-size:9pt;= ">Director, Spatial Hearing Lab</span></span></span><br></p></div><div><= p class=3D"qt-MsoNormal"><span style=3D"color:black;"><span class=3D"fon= t" style=3D"font-family:"Helvetica", sans-serif;"><span class=3D= "size" style=3D"font-size:9pt;">Director, Research Technology</span></sp= an></span><br></p></div><div><p class=3D"qt-MsoNormal"><span style=3D"co= lor:black;"><span class=3D"font" style=3D"font-family:"Helvetica&qu= ot;, sans-serif;"><span class=3D"size" style=3D"font-size:9pt;">Boys Tow= n National Research Hospital</span></span></span><br></p></div><div><p c= lass=3D"qt-MsoNormal"><span style=3D"color:black;"><span class=3D"font" = style=3D"font-family:"Helvetica", sans-serif;"><span class=3D"= size" style=3D"font-size:9pt;"> </span></span></span><br></p></div>= <div><div><p class=3D"qt-MsoNormal"><span style=3D"color:black;"><span c= lass=3D"font" style=3D"font-family:"Helvetica", sans-serif;"><= span class=3D"size" style=3D"font-size:9pt;">Coordinating Editor, Psycho= logical and Physiological Acoustics</span></span></span><br></p></div><d= iv><p class=3D"qt-MsoNormal"><span style=3D"color:black;"><span class=3D= "font" style=3D"font-family:"Helvetica", sans-serif;"><span cl= ass=3D"size" style=3D"font-size:9pt;">Journal of the Acoustical Society = of America</span></span></span><br></p></div></div><div><p class=3D"qt-M= soNormal"><span style=3D"color:black;"><span class=3D"font" style=3D"fon= t-family:"Helvetica", sans-serif;"><span class=3D"size" style=3D= "font-size:9pt;"> </span></span></span><br></p></div><div><p class=3D= "qt-MsoNormal"><span style=3D"color:black;"><span class=3D"font" style=3D= "font-family:"Helvetica", sans-serif;"><span class=3D"size" st= yle=3D"font-size:9pt;"> </span></span></span><br></p></div><div><p = class=3D"qt-MsoNormal"><span style=3D"color:black;"><span class=3D"font"= style=3D"font-family:"Helvetica", sans-serif;"><span class=3D= "size" style=3D"font-size:9pt;"><a href=3D"mailto:cstecker@xxxxxxxx= g.org">cstecker@xxxxxxxx</a></span></span></span><br></p></div= ><div><p class=3D"qt-MsoNormal"><span style=3D"color:black;"><span class= =3D"font" style=3D"font-family:"Helvetica", sans-serif;"><span= class=3D"size" style=3D"font-size:9pt;"><a href=3D"http://www.spatialhe= aring.org">www.spatialhearing.org</a></span></span></span><br></p></div>= </div><p class=3D"qt-MsoNormal"><span style=3D"color:black;"><span class= =3D"font" style=3D"font-family:"Helvetica", sans-serif;"><span= class=3D"size" style=3D"font-size:9pt;"> </span></span></span><br>= </p></div><p class=3D"qt-MsoNormal"><span style=3D"color:black;"><span c= lass=3D"font" style=3D"font-family:"Helvetica", sans-serif;"><= span class=3D"size" style=3D"font-size:9pt;"> </span></span></span>= <br></p></div><p class=3D"qt-MsoNormal"><span style=3D"color:black;"><sp= an class=3D"font" style=3D"font-family:"Helvetica", sans-serif= ;"><span class=3D"size" style=3D"font-size:9pt;"> </span></span></s= pan><br></p></div><p class=3D"qt-MsoNormal"><span style=3D"color:black;"= ><span class=3D"font" style=3D"font-family:"Helvetica", sans-s= erif;"><span class=3D"size" style=3D"font-size:9pt;"> </span></span= ></span><br></p></div><p class=3D"qt-MsoNormal"><span style=3D"color:bla= ck;"><span class=3D"font" style=3D"font-family:"Helvetica", sa= ns-serif;"><span class=3D"size" style=3D"font-size:9pt;"> </span></= span></span><br></p></div><p class=3D"qt-MsoNormal"><span style=3D"color= :black;"><span class=3D"font" style=3D"font-family:"Helvetica"= , sans-serif;"><span class=3D"size" style=3D"font-size:9pt;"> </spa= n></span></span><br></p></div><p class=3D"qt-MsoNormal" style=3D"margin-= bottom:12pt;"> <br></p></div><p class=3D"qt-MsoNormal"> <br></= p><div><blockquote style=3D"margin-top:5pt;margin-bottom:5pt;"><div><p c= lass=3D"qt-MsoNormal">On Aug 15, 2022, at 3:23 AM, Prof Leslie Smith <= ;<a href=3D"mailto:l.s.smith@xxxxxxxx">l.s.smith@xxxxxxxx</a>&= gt; wrote:<br></p></div><p class=3D"qt-MsoNormal"> <br></p><div><di= v><p class=3D"qt-MsoNormal"><br></p><div>Dear all:<br></div><div> <br></= div><div> Some years ago, I worked on using sound at onsets for calculat= ing source<br></div><div> direction in reverberant environments [1]. It'= s kind-of obvious, because<br></div><div> after the onset, the sound at = the ear/microphone is made up of energy both<br></div><div> from the sou= rce and from reflections.<br></div><div> <br></div><div> Sampling rates = are normally constant, and techniques for compression are<br></div><div>= aimed at recreating the percept of the original sound: I am under the<b= r></div><div> impression that this doesn't extend to the percept of prec= ise location of<br></div><div> the sound. Perhaps we need novel compress= ion/decompression techniques<br></div><div> that include the relev= ant data for source location.<br></div><div> <br></div><div> [1] L.S. Sm= ith, S. Collins Determining ITDs using two microphones on a<br></div><di= v> flat panel during onset intervals with a biologically inspired spike = based<br></div><div> technique<br></div><div> IEEE Transactions of Audio= , Speech and Language Processing, 15, 8,<br></div><div> 2278-2286, (2007= ).<br></div><div> <br></div><div> --Leslie Smith<br></div><div> <br></di= v><div> Adam Weisser wrote:<br></div><div> <br></div><div> <br></div><p>= <br></p><blockquote style=3D"margin-top:5pt;margin-bottom:5pt;"><p class= =3D"qt-MsoNormal" style=3D"margin-bottom:12pt;"><br></p><div>1. Compress= ed sensing - This heavily researched signal-processing method<br></div><= div> uses signal sparsity to faithfully reconstruct undersampled signals= [1].<br></div><p><br></p></blockquote><p class=3D"qt-MsoNormal"><br></p= ><div>.....<br></div><div> <br></div><p><br></p><blockquote style=3D"mar= gin-top:5pt;margin-bottom:5pt;"><p class=3D"qt-MsoNormal" style=3D"margi= n-bottom:12pt;"><br></p><div>Neural adaptation can be thought of as dens= e<br></div><div> sampling of the signal around its onset / transient por= tion, which becomes<br></div><div> more sparsely sampled quickly after t= he onset. Because of adaptation, this<br></div><div> effect is very illu= sive, but I believe that it is measurable<br></div><div> notwithstanding= . I tried to demonstrate it psychoacoustically in Appendix<br></div><div= > E of [4]. While I don't know how it relates to binaural processing<br>= </div><div> directly, there may be instantaneous effects that may be det= ectable there<br></div><div> too, given that the input to both processin= g types is the same.<br></div><div> <br></div><div> All the best,<br></d= iv><div> Adam.<br></div><p><br></p></blockquote><p class=3D"qt-MsoNormal= "><br></p><div>...<br></div><div> <br></div><div> <br></div><div> -- <br= ></div><div> Prof Leslie Smith (Emeritus)<br></div><div> Computing Scien= ce & Mathematics,<br></div><div> University of Stirling, Stirling FK= 9 4LA<br></div><div> Scotland, UK<br></div><div> Tel +44 1786 467435<br>= </div><div> Web: <a href=3D"http://www.cs.stir.ac.uk/~lss">http://www.cs= .stir.ac.uk/~lss</a><br></div><div> Blog: <a href=3D"http://lestheprof.c= om">http://lestheprof.com</a><br></div><p><br></p></div></div></blockquo= te></div><p class=3D"qt-MsoNormal"> <br></p></div></div><p style=3D= "margin-top:0cm;margin-right:0cm;margin-bottom:0pt;margin-left:0cm;" cla= ss=3D"qt-MsoNormal"><span style=3D""><span class=3D"font" style=3D"font-= family:"Arial", "sans-serif";"><span class=3D"size" = style=3D"font-size:8pt;"> </span></span></span><br></p><div><span c= lass=3D"size" style=3D"font-size:16px;"></span><br></div><p style=3D"mar= gin-top:0cm;margin-right:0cm;margin-bottom:0pt;margin-left:0cm;" class=3D= "qt-MsoNormal"><span class=3D"size" style=3D"font-size:16px;"><span styl= e=3D""><span class=3D"font" style=3D"font-family:"Arial", &quo= t;sans-serif";"><span class=3D"size" style=3D"font-size:8pt;">This = message may contain information that is not intended for you. If you are= not the addressee or if this message was sent to you by mistake, you ar= e requested to inform the sender and delete the message. TNO accepts no = liability for the content of this e-mail, for the manner in which you us= e it and for damage of any kind resulting from the risks inherent to the= electronic transmission of messages.<br></span></span></span></span></p= ></blockquote><div style=3D"font-family:Arial;"><br></div></body></html> --e8241ae01caf4c8cbec974da67cc371a--