Subject: Re: [AUDITORY] Seeking advice on using ANF firing rate to reslove front-back confusion in sound localization model From: "Richard F. Lyon" <0000030301ff4bce-dmarc-request@xxxxxxxx> Date: Thu, 27 Feb 2025 22:08:01 +1100--000000000000c13753062f1db4ce Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Qin, The rate-vs-place profiles from the two ears may have most of what you need to supplement the MSO's output that represents ITD, which is mostly a left-right cue. The cues for elevation, including front-back, are generally thought to be more subtle spectral features, related to the individual's HRTF, and are not as robust as the ITD cues. ILD cues are of intermediate robustness, I think, but still primarily left-right. I hadn't thought about doing what Jan Schnupp suggested, looking at slightly different cones of confusion for different frequencies, but that sounds like another way to conceptualize the subtle HRTF-dependent spectral cues. So you don't have to use "HRTF template matching", but you do have to use HRTFs. If you want to do this in anything like the real world, as opposed to an anechoic environment, you'll need a strong precedence effect to pay attention to the first arrival and ignore echos, or something along those lines. Also, in the real world, we usually resolve front-back confusion quickly and easily by rotating our heads a little. The effect of rotation on ITD is opposite for front vs back, so this gives a very robust front-back cue; up-down is still hard. Dick On Wed, Feb 26, 2025 at 4:21=E2=80=AFPM Qin Liu < 000003c563e12bd3-dmarc-request@xxxxxxxx> wrote: > Dear auditory list, > > I am currently working on a project involving sound localization using > firing rates from auditory nerve fibers (ANFs) and the medial superior > olive (MSO). However, I have encountered an issue: I am unable to > distinguish between front and back sound sources using MSO firing rates > alone but only the left-right. > > I am considering whether auditory nerve fiber (ANF) firing rates might > provide a solution, but I am uncertain how to utilize them effectively. F= or > instance, I have experimented with analyzing the positive gradients of AN= F > firing rates but have not yet achieved meaningful results. > > Could anyone suggest an auditory metric derived from binaural signals, AN= F > firing rates, or MSO that could classify front/back sources without relyi= ng > on HRTF template matching? Any insights or alternative approaches would b= e > invaluable to my work. > > Thank you in advance. I sincerely appreciate any guidance you can offer. > > Best regards, > > *Qin Liu* > Doctoral Student > Laboratory of Wave Engineering, =C3=89cole Polytechnique F=C3=A9d=C3=A9ra= le de Lausanne > (EPFL) > Email: qin.liu@xxxxxxxx > > > --000000000000c13753062f1db4ce Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable <div dir=3D"ltr"><div class=3D"gmail_default" style=3D"font-size:small">Qin= ,</div><div class=3D"gmail_default" style=3D"font-size:small"><br></div><di= v class=3D"gmail_default" style=3D"font-size:small">The rate-vs-place profi= les from the two ears may have most of what you need to supplement the MSO&= #39;s output that represents ITD, which is mostly a left-right cue.=C2=A0 T= he cues for elevation, including front-back, are generally thought to be mo= re subtle spectral features, related to the individual's HRTF, and are = not as robust as the ITD cues.=C2=A0 ILD cues are of intermediate robustnes= s, I think, but still primarily left-right.</div><div class=3D"gmail_defaul= t" style=3D"font-size:small"><br></div><div class=3D"gmail_default" style= =3D"font-size:small">I hadn't thought about doing what Jan Schnupp sugg= ested, looking at slightly different cones of confusion for different frequ= encies, but that sounds like another way to conceptualize the subtle HRTF-d= ependent spectral cues.</div><div class=3D"gmail_default" style=3D"font-siz= e:small"><br></div><div class=3D"gmail_default" style=3D"font-size:small">S= o you don't have to use "HRTF template matching", but you do = have to use HRTFs.</div><div class=3D"gmail_default" style=3D"font-size:sma= ll"><br></div><div class=3D"gmail_default" style=3D"font-size:small">If you= want to do this in anything like the real world, as opposed to an anechoic= environment, you'll need a strong precedence effect to pay attention t= o the first arrival and ignore echos, or something along those lines.=C2=A0= <br></div><div class=3D"gmail_default" style=3D"font-size:small"><br></div= ><div class=3D"gmail_default" style=3D"font-size:small">Also, in the real w= orld, we usually resolve front-back confusion quickly and easily by rotatin= g our heads a little.=C2=A0 The effect of rotation on ITD is opposite for f= ront vs back, so this gives a very robust front-back cue; up-down is still = hard.</div><div class=3D"gmail_default" style=3D"font-size:small"><br></div= ><div class=3D"gmail_default" style=3D"font-size:small">Dick</div><div clas= s=3D"gmail_default" style=3D"font-size:small"><br></div></div><br><div clas= s=3D"gmail_quote gmail_quote_container"><div dir=3D"ltr" class=3D"gmail_att= r">On Wed, Feb 26, 2025 at 4:21=E2=80=AFPM Qin Liu <<a href=3D"mailto:00= 0003c563e12bd3-dmarc-request@xxxxxxxx">000003c563e12bd3-dmarc-reques= t@xxxxxxxx</a>> wrote:<br></div><blockquote class=3D"gmail_quote"= style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);p= adding-left:1ex"><div class=3D"msg-2480699540356499465"> <div dir=3D"ltr"> <div id=3D"m_8012116099777483196divtagdefaultwrapper" dir=3D"ltr" style=3D"= font-size:12pt;color:rgb(0,0,0);font-family:Calibri,Helvetica,sans-serif,Em= ojiFont,"Apple Color Emoji","Segoe UI Emoji",NotoColorE= moji,"Segoe UI Symbol","Android Emoji",EmojiSymbols"> <p>Dear auditory list,</p> <div><br> I am currently working on a project involving sound localization using firi= ng rates from auditory nerve fibers (ANFs) and the medial superior olive (M= SO). However, I have encountered an issue: I am unable to distinguish betwe= en front and back sound sources using MSO firing rates alone but only the left-right.<br> <br> I am considering whether auditory nerve fiber (ANF) firing rates might prov= ide a solution, but I am uncertain how to utilize them effectively. For ins= tance, I have experimented with analyzing the positive gradients of ANF fir= ing rates but have not yet achieved meaningful results.<br> <br> Could anyone suggest an auditory metric derived from binaural signals, ANF = firing rates, or MSO that could classify front/back sources without relying= on HRTF template matching? Any insights or alternative approaches would be= invaluable to my work.<br> <br> Thank you in advance. I sincerely appreciate any guidance you can offer.<br= > <br> Best regards,<br> <br> <b></b><strong>Qin Liu</strong><span style=3D"color:rgba(0,0,0,0.9);font-fa= mily:"PingFang SC",-apple-system,BlinkMacSystemFont,"Segoe U= I",Roboto,Ubuntu,"Helvetica Neue",Helvetica,Arial,"Hira= gino Sans GB","Microsoft YaHei UI","Microsoft YaHei&quo= t;,"Source Han Sans CN",sans-serif;font-size:16px;background-colo= r:rgb(252,252,252)"></span><br style=3D"color:rgba(0,0,0,0.9);font-family:&= quot;PingFang SC",-apple-system,BlinkMacSystemFont,"Segoe UI"= ;,Roboto,Ubuntu,"Helvetica Neue",Helvetica,Arial,"Hiragino S= ans GB","Microsoft YaHei UI","Microsoft YaHei",&qu= ot;Source Han Sans CN",sans-serif;font-size:16px;background-color:rgb(= 252,252,252)"> <span>Doctoral Student</span><span style=3D"color:rgba(0,0,0,0.9);font-fami= ly:"PingFang SC",-apple-system,BlinkMacSystemFont,"Segoe UI&= quot;,Roboto,Ubuntu,"Helvetica Neue",Helvetica,Arial,"Hiragi= no Sans GB","Microsoft YaHei UI","Microsoft YaHei"= ,"Source Han Sans CN",sans-serif;font-size:16px;background-color:= rgb(252,252,252)"></span><br style=3D"color:rgba(0,0,0,0.9);font-family:&qu= ot;PingFang SC",-apple-system,BlinkMacSystemFont,"Segoe UI",= Roboto,Ubuntu,"Helvetica Neue",Helvetica,Arial,"Hiragino San= s GB","Microsoft YaHei UI","Microsoft YaHei","= ;Source Han Sans CN",sans-serif;font-size:16px;background-color:rgb(25= 2,252,252)"> <span style=3D"color:rgba(0,0,0,0.9);font-family:"PingFang SC",-a= pple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Ubuntu,"Hel= vetica Neue",Helvetica,Arial,"Hiragino Sans GB","Micros= oft YaHei UI","Microsoft YaHei","Source Han Sans CN&quo= t;,sans-serif;font-size:16px;background-color:rgb(252,252,252)">Laboratory of Wave Engineering,=C2=A0</span><span style=3D"color:rgba(0,0,0,0.9);font= -family:"PingFang SC",-apple-system,BlinkMacSystemFont,"Sego= e UI",Roboto,Ubuntu,"Helvetica Neue",Helvetica,Arial,"H= iragino Sans GB","Microsoft YaHei UI","Microsoft YaHei&= quot;,"Source Han Sans CN",sans-serif;font-size:16px;background-c= olor:rgb(252,252,252)">=C3=89cole Polytechnique F=C3=A9d=C3=A9rale de Lausanne (EPFL)</span><br style=3D"col= or:rgba(0,0,0,0.9);font-family:"PingFang SC",-apple-system,BlinkM= acSystemFont,"Segoe UI",Roboto,Ubuntu,"Helvetica Neue",= Helvetica,Arial,"Hiragino Sans GB","Microsoft YaHei UI"= ,"Microsoft YaHei","Source Han Sans CN",sans-serif;font= -size:16px;background-color:rgb(252,252,252)"> <span style=3D"color:rgba(0,0,0,0.9);font-family:"PingFang SC",-a= pple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Ubuntu,"Hel= vetica Neue",Helvetica,Arial,"Hiragino Sans GB","Micros= oft YaHei UI","Microsoft YaHei","Source Han Sans CN&quo= t;,sans-serif;font-size:16px;background-color:rgb(252,252,252)">Email: <a href=3D"mailto:qin.liu@xxxxxxxx" target=3D"_blank">qin.liu@xxxxxxxx</a></= span></div> <br> <br> <p></p> </div> </div> </div></blockquote></div> --000000000000c13753062f1db4ce--