Subject: [AUDITORY] Cochlear Implants - To interleave or not to interleave? From: Jan Schnupp <000000e042a1ec30-dmarc-request@xxxxxxxx> Date: Wed, 28 Sep 2022 16:24:19 +0800--000000000000e8283a05e9b87e93 Content-Type: text/plain; charset="UTF-8" Dear List, it is my understanding that the vast majority of CI sound processors in use today are still based or inspired more or less on some variant of the Continuous Interleaved Sampling algorithm, and that one of the key assumptions / design features of the algorithms in use is that having more than one electrode channel active in any one ear at the same time is to be avoided. Hence "interleaved" sampling: channels take turns to ensure they aren't active at once. What I am curious to know is: quite how bad would it be if this assumption was violated? Is it necessarily always very bad? And how certain can we be about how bad it is? Have people run head-to-head comparisons of strategies with and without strict interleaving? Intuitively, while I see that having multiple channels active at once may exacerbate problems with the already relatively poor channel isolation, I also think that forcing channels to fire "in turn" constrains the timing of pulses in a manner that may preclude independent temporal coding on different channels. Has this potential trade-off been considered? Is there a well founded consensus that the downsides of having the potential of temporal collisions of pulses in different channels will necessarily outweigh potential upsides from having richer temporal patterning across channels? I would be grateful for references / papers / views / perspectives relevant to this topic. Many thanks! Jan --------------------------------------- Prof Jan Schnupp City University of Hong Kong Dept. of Neuroscience 31 To Yuen Street, Kowloon Tong Hong Kong https://auditoryneuroscience.com http://jan.schnupp.net --000000000000e8283a05e9b87e93 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable <div dir=3D"ltr">Dear List,<div><br></div><div>it is my understanding that = the vast majority of CI sound processors in use today are still based or in= spired more or less=C2=A0on some variant of the Continuous Interleaved Samp= ling algorithm, and that one of the key assumptions / design features of th= e algorithms in use is that having more than one electrode channel active i= n any one ear at the same time is to be avoided. Hence "interleaved&qu= ot; sampling: channels take turns to ensure they aren't active at once.= What I am curious to know is: quite how bad would it be if this assumption= was violated? Is it necessarily=C2=A0always very bad? And how certain can = we be about how bad it is? Have=C2=A0people run head-to-head comparisons of= strategies with and without strict interleaving?=C2=A0</div><div>Intuitive= ly, while I see that having multiple channels active at once may exacerbate= problems with the already relatively poor channel isolation, I also think = that forcing channels to fire "in turn" constrains the timing of = pulses in a manner that may preclude independent temporal coding on differe= nt channels. Has this potential trade-off been considered? Is there a well = founded consensus that the downsides of having the potential of temporal co= llisions of pulses in different channels will necessarily outweigh potentia= l upsides from having richer temporal patterning across channels?=C2=A0</di= v><div><br></div><div>I would be grateful for references / papers / views /= perspectives relevant to this topic.</div><div><br></div><div>Many thanks!= </div><div><br></div><div>Jan</div><div><div><div dir=3D"ltr" class=3D"gmai= l_signature" data-smartmail=3D"gmail_signature"><div dir=3D"ltr"><div><div = dir=3D"ltr"><div><div dir=3D"ltr"><div dir=3D"ltr"><div dir=3D"ltr"><div di= r=3D"ltr"><div style=3D"font-size:12.8px"><br></div><div style=3D"font-size= :12.8px">---------------------------------------</div><div style=3D"font-si= ze:12.8px">Prof Jan Schnupp<br>City University of Hong Kong<br>Dept. of Neu= roscience</div><div><div style=3D"font-size:12.8px">31 To Yuen Street,=C2= =A0</div><div style=3D"font-size:12.8px"><span style=3D"font-size:12.8px">K= owloon Tong</span></div><div style=3D"font-size:12.8px">Hong Kong</div><div= style=3D"font-size:12.8px"><br></div><a href=3D"https://auditoryneuroscien= ce.com" target=3D"_blank">https://auditoryneuroscience.com</a></div><div><a= href=3D"http://jan.schnupp.net" target=3D"_blank">http://jan.schnupp.net</= a></div></div></div></div></div></div></div></div></div></div></div></div><= /div> --000000000000e8283a05e9b87e93--