Subject: [AUDITORY] Presenting of the Temporal Auditory Imaging Theory From: Adam Weisser <adam_weisser@xxxxxxxx> Date: Wed, 17 Nov 2021 12:15:14 +0200--001944d90b8f4e339e94a807e3fc4bc2 Content-Type: text/plain Content-Transfer-Encoding: quoted-printable Dear all, As is widely known, the function of the human eye can be explained relat= ively straightforwardly using basic optical principles, where the eye ca= n be likened to a camera with a single lens, whose image appears on the = retina, where it is transduced and neurally encoded. Despite a long trad= ition of drawing analogies between vision and hearing, the ear has resis= ted a comparably simple description. I would like to present a rigorous = analogy between the optics of the eye and the signal processing of the e= ar all the way to the midbrain. According to this novel theory, the dist= ance from the visual object is analogized to cochlear dispersion, the cr= ystalline lens to a cochlear time lens, and the distance between the len= s and the retina to the neural dispersion between the cochlea and the in= ferior colliculus. The "currency" of the auditory signal turns out to be= the degree of coherence of the acoustic source. While undoubtedly many of you may find these ideas speculative, I believ= e that they can be well established using available evidence from litera= ture with relatively few missing elements. Should it be accepted, this t= heory could have high explanatory power and open new avenues of understa= nding the hearing function and its internal logic.=20 With more than 1500 references, the theory synthesizes ideas from numero= us people on the Auditory List, past research in acoustics and hearing, = and findings from related disciplines: https://arxiv.org/abs/2111.04338 I invite you to explore this text and these ideas and decide for yoursel= ves.=20 Any feedback, questions, suggestions for refinements or corrections woul= d be most welcome.=20 Thank you, Adam Weisser, PhD.=20 *Treatise on Hearing: **The Temporal Auditory Imaging Theory Inspired by= Optics and Communication* _Abstract_ A new theory of mammalian hearing is presented, which accounts for the a= uditory image in the midbrain (inferior colliculus) of objects in the ac= oustical environment of the listener. It is shown that the ear is a temp= oral imaging system that comprises three transformations of the envelope= functions: cochlear group-delay dispersion, cochlear time lensing, and = neural group-delay dispersion. These elements are analogous to the famil= iar transformations from the visual system of diffraction between the ob= ject and the eye, spatial lensing by the crystalline lens, and second di= ffraction between the lens and the retina. However, unlike the eye, it i= s established that the human auditory system is naturally defocused, so = that coherent stimuli do not react to the defocus, whereas completely in= coherent stimuli are impacted by the defocus and may be blurred by desig= n. It is argued that the auditory system can use this differential focus= ing to enhance or degrade the images of real-world acoustical objects th= at are partially coherent, predominantly.=20 The theory is founded on coherence and temporal imaging theories that we= re adopted from optics. In addition to the imaging transformations, the = corresponding inverse-domain modulation transfer functions are derived a= nd interpreted with consideration to the nonuniform neural sampling oper= ation of the auditory nerve. These ideas are used to rigorously initiate= the concepts of sharpness and blur in auditory imaging, auditory aberra= tions, and auditory depth of field.=20 In parallel, ideas from communication theory are used to show that the o= rgan of Corti functions as a multichannel phase-locked loop (PLL) that c= onstitutes the point of entry for auditory phase locking. It provides an= anchor for a dual coherent and noncoherent auditory detection further d= ownstream in the auditory brain. Phase locking enables conservation of c= oherence between the mechanical and neural domains. Combining the logic of both imaging and phase locking, it is speculated = that the auditory system should be able to dynamically adjust the propor= tion of coherent and noncoherent processing that comprises the final ima= ge or detected product. This can be the basis for auditory accommodation= , in analogy to the accommodation of the eye. Such a function may be ach= ieved primarily through the olivocochlear efferent bundle, although addi= tional accommodative brainstem circuits are considered as well. The hypothetical effect of dispersion and synchronization anomalies in h= earing impairments is considered. While much evidence is still lacking t= o make it less speculative, it is concluded that impairments as a result= of accommodation dysfunction and excessive higher-order aberrations may= have a role in known hearing-impairment effects. https://arxiv.org/abs/2111.04338 --001944d90b8f4e339e94a807e3fc4bc2 Content-Type: text/html Content-Transfer-Encoding: quoted-printable <!DOCTYPE html><html><head><title></title><style type=3D"text/css">p.Mso= Normal,p.MsoNoSpacing{margin:0} p.MsoNormal,p.MsoNoSpacing{margin:0} p.MsoNormal,p.MsoNoSpacing{margin:0}</style></head><body><div style=3D"f= ont-family:Arial;">Dear all,<br></div><div style=3D"font-family:Arial;">= <br></div><div style=3D"font-family:Arial;">As is widely known, the func= tion of the human eye can be explained relatively straightforwardly usin= g basic optical principles, where the eye can be likened to a camera wit= h a single lens, whose image appears on the retina, where it is transduc= ed and neurally encoded. Despite a long tradition of drawing analogies b= etween vision and hearing, the ear has resisted a comparably simple desc= ription. I would like to present a rigorous analogy between the optics o= f the eye and the signal processing of the ear all the way to the midbra= in. According to this novel theory, the distance from the visual ob= ject is analogized to cochlear dispersion, the crystalline lens to a coc= hlear time lens, and the distance between the lens and the retina to the= neural dispersion between the cochlea and the inferior colliculus. The = "currency" of the auditory signal turns out to be the degree of coherenc= e of the acoustic source.<br></div><div style=3D"font-family:Arial;"><br= ></div><div style=3D"font-family:Arial;">While undoubtedly many of you m= ay find these ideas speculative, I believe that they can be well establi= shed using available evidence from literature with relatively few missin= g elements. Should it be accepted, this theory could have high explanato= ry power and open new avenues of understanding the hearing function and = its internal logic. <br></div><div style=3D"font-family:Arial;"><br></di= v><div style=3D"font-family:Arial;">With more than 1500 references, the = theory synthesizes ideas from numerous people on the Auditory List, past= research in acoustics and hearing, and findings from related discipline= s:<br></div><div style=3D"font-family:Arial;"><br></div><div style=3D"fo= nt-family:Arial;"><a href=3D"https://arxiv.org/abs/2111.04338" rel=3D"no= opener noreferrer" target=3D"_blank">https://arxiv.org/abs/2111.04338</a= ><br></div><div style=3D"font-family:Arial;"><br></div><div style=3D"fon= t-family:Arial;">I invite you to explore this text and these ideas and d= ecide for yourselves. <br></div><div style=3D"font-family:Arial;"><br></= div><div style=3D"font-family:Arial;">Any feedback, questions, suggestio= ns for refinements or corrections would be most welcome. <br></div><div = style=3D"font-family:Arial;"><br></div><div style=3D"font-family:Arial;"= >Thank you,<br></div><div style=3D"font-family:Arial;">Adam Weisser, PhD= . <br></div><div style=3D"font-family:Arial;"><br></div><div style=3D"fo= nt-family:Arial;"><br></div><div style=3D"font-family:Arial;"><b>Treatis= e on Hearing: </b><b>The Temporal Auditory Imaging Theory Inspired by Op= tics and Communication</b><br></div><div style=3D"font-family:Arial;"><u= >Abstract</u><br></div><div style=3D"font-family:Arial;"><br></div><div = style=3D"font-family:Arial;">A new theory of mammalian hearing is presen= ted, which accounts for the auditory image in the midbrain (inferior col= liculus) of objects in the acoustical environment of the listener. It is= shown that the ear is a temporal imaging system that comprises three tr= ansformations of the envelope functions: cochlear group-delay dispersion= , cochlear time lensing, and neural group-delay dispersion. These elemen= ts are analogous to the familiar transformations from the visual system = of diffraction between the object and the eye, spatial lensing by the cr= ystalline lens, and second diffraction between the lens and the retina. = However, unlike the eye, it is established that the human auditory syste= m is naturally defocused, so that coherent stimuli do not react to the d= efocus, whereas completely incoherent stimuli are impacted by the defocu= s and may be blurred by design. It is argued that the auditory system ca= n use this differential focusing to enhance or degrade the images of rea= l-world acoustical objects that are partially coherent, predominantly. <= br></div><div style=3D"font-family:Arial;"><br></div><div style=3D"font-= family:Arial;">The theory is founded on coherence and temporal imaging t= heories that were adopted from optics. In addition to the imaging transf= ormations, the corresponding inverse-domain modulation transfer function= s are derived and interpreted with consideration to the nonuniform neura= l sampling operation of the auditory nerve. These ideas are used to rigo= rously initiate the concepts of sharpness and blur in auditory imaging, = auditory aberrations, and auditory depth of field. <br></div><div s= tyle=3D"font-family:Arial;"><br></div><div style=3D"font-family:Arial;">= In parallel, ideas from communication theory are used to show that the o= rgan of Corti functions as a multichannel phase-locked loop (PLL) that c= onstitutes the point of entry for auditory phase locking. It provides an= anchor for a dual coherent and noncoherent auditory detection further d= ownstream in the auditory brain. Phase locking enables conservation of c= oherence between the mechanical and neural domains.<br></div><div style=3D= "font-family:Arial;"><br></div><div style=3D"font-family:Arial;">Combini= ng the logic of both imaging and phase locking, it is speculated that th= e auditory system should be able to dynamically adjust the proportion of= coherent and noncoherent processing that comprises the final image or d= etected product. This can be the basis for auditory accommodation, in an= alogy to the accommodation of the eye. Such a function may be achieved p= rimarily through the olivocochlear efferent bundle, although additional = accommodative brainstem circuits are considered as well.<br></div><div s= tyle=3D"font-family:Arial;"><br></div><div style=3D"font-family:Arial;">= The hypothetical effect of dispersion and synchronization anomalies in h= earing impairments is considered. While much evidence is still lacking t= o make it less speculative, it is concluded that impairments as a result= of accommodation dysfunction and excessive higher-order aberrations may= have a role in known hearing-impairment effects.<br></div><div style=3D= "font-family:Arial;"><br></div><div style=3D"font-family:Arial;"><a href= =3D"https://arxiv.org/abs/2111.04338" rel=3D"noopener noreferrer" target= =3D"_blank">https://arxiv.org/abs/2111.04338</a><br></div></body></html> --001944d90b8f4e339e94a807e3fc4bc2--