Subject: Question about latency in CI comprehension From: Nathan Barlow <nbar067@xxxxxxxx> Date: Mon, 8 Dec 2014 22:33:00 +1300 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>--001a1136b54acddb9d0509b11c65 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Dear Tamas, I'm not sure if you are familiar with cortical auditory evoked potentials (CAEPs), especially in the context of cochlear implants. For a good starting place in the literature, here is a study on 12 experienced adult users of cochlear implants, relating several types of evoked potentials and behavioural measures (such as speech perception scores) with age- and sex-controlled matches: http://dx.doi.org/10.1016/j.clinph.2005.02.011 In general, when looking at auditory processing objectively (such as with evoked potentials), there does seem to be a consistent latency increase for cochlear implant users, in not only the earlier Middle Latency Responses (see Gordan et al 2005 for a child specific study), but also P1, N1 and P2 of the obligatory cortical responses (aka CAEPs). Latency differs when compared to the expected age-controlled normal hearing latency, most commonly a delay of some length. I have seen in the ballpark of 50-80ms delays, but have also seen CI users who have latencies comparable to generalized hearing 'norms'. These are usually people who lost hearing either progressively, or lost hearing suddenly later in their life, but not always. Usual explanations for the latency increases, are along the lines of auditory processing time is longer, dependant on the participants audiological history. In terms of objective evidence of that concept, I would suggest looking to the literature on Mis-Match Negativity (MMN), as this looks at attentional paradigms as well. In terms of your specific question with unilateral loss and cochlear implants, I would be tempted to look at the engineering side of the device, or possibly the settings of the implant programming, but you mention you do not think the delay is a technical one. Another area to consider may be the idea of hemispheric connectivity. In your example of a unilateral loss with the CI in the deaf ear , it may be that the non-CI (and fully hearing ear) input is processing faster in the brain than the CI input is. This is an extension of the concept that auditory-deprivation impacts on plasticity . But I have nothing concrete to support this theory. Maybe someone else on this list might be of more help there. As a CI user myself, I can say that fatigue is what makes me need to take more time to process. Often I can ask for a repetition, then halfway through the first word of the repeat, can realise what the whole sentence was from the first time it was said. That could be more scientifically explored/explained in terms of attention, I would imagine. Kind Regards Nathan Barlow References: Gordon KA, Papsin BC, and Harrison RV. (2005) Effects of cochlear implant use on the electrically evoked middle latency response in children.Hear Res. 204(1-2). 78-89. Kelly A.S, Purdy, S.C, and Thorne, P.R. (2005). Electrophysiological and speech perception measures of auditory processing in experienced adult cochlear implant users, Clinical Neurophysiology, 116 (6); 1235-1246 On 6 December 2014 at 00:10, Tam=C3=A1s Harczos <tamas.harczos@xxxxxxxx= nau.de <javascript:_e(%7B%7D,'cvml','tamas.harczos@xxxxxxxx');>> wrote: > Dear List, > > while working with cochlear implants (CI) I often notice that even CI > listeners with very good speech perception need some extra time (in > comparison to normal hearing listeners) to comprehend a spoken sentence. > In fact, some patients with single-sided deafness and CI in the deaf ear > report a perceived latency between the normal hearing and the CI side, > which does not seem to be of technical nature. > > Could any of you point me to relevant literature or published studies > related to this phenomenon? > > Thank you! > Tamas > > -- > *~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~* > Dipl.-Ing. Tam=C3=A1s Harczos > PhD Student > Institute for Media Technology > Faculty of Electr. Eng. and Inf. Techn. > Ilmenau University of Technology > Tel.: +49 3677 467 225 > Fax.: +49 3677 467 4225 > E-Mail: tamas.harczos@xxxxxxxx > <javascript:_e(%7B%7D,'cvml','tamas.harczos@xxxxxxxx');> > *~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~* > --------------------------- Nathan Barlow ---------------------------- M.Sc Student Discipline of Speech Science University of Auckland nbar067@xxxxxxxx <javascript:_e(%7B%7D,'cvml','nbar067@xxxxxxxx');> --=20 Nathan Barlow ---------------------------- M.Sc student 1002702 Discipline of Speech Science University of Auckland nbar067@xxxxxxxx --001a1136b54acddb9d0509b11c65 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable <div dir=3D"ltr">Dear Tamas,<br><br>I'm not sure if you are familiar wi= th=C2=A0cortical auditory evoked potentials (CAEPs), especially in the cont= ext of=C2=A0cochlear implants. For a good starting place in the literature,= here is a study on 12 experienced adult users of cochlear implants, relati= ng several types of evoked potentials and behavioural measures (such as spe= ech perception scores) with age- and sex-controlled matches: <span style=3D= "color:rgb(0,0,0);white-space:pre-wrap"><a href=3D"http://dx.doi.org/10.101= 6/j.clinph.2005.02.011" target=3D"_blank">http://dx.doi.org/10.1016/j.clinp= h.2005.02.011</a></span><br><br>In general, when looking at auditory proces= sing objectively (such as with evoked potentials), there does seem to be a = consistent latency increase for cochlear implant users, in not only the ear= lier Middle Latency Responses (see Gordan et al 2005 for a child specific s= tudy), but also P1, N1 and P2 of the obligatory cortical responses (aka CAE= Ps). Latency differs when compared to the expected age-controlled normal he= aring latency, most commonly a delay of some length. I have seen in the bal= lpark of 50-80ms delays, but have also seen CI users who have latencies com= parable to generalized hearing 'norms'. These are usually people wh= o lost hearing either progressively, or lost hearing suddenly later in thei= r life, but not always.<br><br>Usual explanations for the latency increases= , are along the lines of auditory processing time is longer, dependant on t= he participants audiological history. In terms of objective evidence of tha= t concept, I would suggest looking to the literature on Mis-Match Negativit= y (MMN), as this looks at attentional paradigms as well.<br><br>In terms of= your =C2=A0specific question with unilateral loss and cochlear implants, I= would be tempted to look at the engineering side of the device, or possibl= y the settings of the implant programming, but you mention you do not think= the delay is a technical one. Another area to consider may be the idea of = hemispheric connectivity. In your example of a unilateral loss with the CI = in the deaf ear , it may be that the non-CI (and fully hearing ear) input i= s processing faster in the brain than the CI input is. This is an extension= of the=C2=A0concept that=C2=A0auditory-deprivation impacts on plasticity .= But I have nothing concrete to support this theory. Maybe someone else on = this list might be of more help there.<br><br><br>As a CI user myself, I ca= n say that fatigue is what makes me need to take more time to process. Ofte= n I can ask for a repetition, then halfway through the first word of the re= peat, can realise what the whole sentence was from the first time it was sa= id. That could be more scientifically explored/explained in terms of attent= ion, I would imagine.<br><br><br>Kind Regards<br>Nathan Barlow<br><br><br><= br>References:<br><br><blockquote style=3D"margin:0 0 0 40px;border:none;pa= dding:0px">Gordon KA, Papsin BC, and Harrison RV. (2005) Effects of cochlea= r implant use on the electrically evoked middle latency response in childre= n.Hear Res. 204(1-2). 78-89.<br><br>Kelly A.S, Purdy, S.C, and Thorne, P.R.= (2005). Electrophysiological and speech perception measures of auditory pr= ocessing in experienced adult cochlear implant users, Clinical Neurophysiol= ogy, 116 (6); 1235-1246</blockquote><div class=3D"gmail_extra"><div class= =3D"gmail_quote"><br></div><div class=3D"gmail_quote"><br></div><div class= =3D"gmail_quote">On 6 December 2014 at 00:10, Tam=C3=A1s Harczos <span dir= =3D"ltr"><<a href=3D"javascript:_e(%7B%7D,'cvml','tamas.harc= zos@xxxxxxxx');" target=3D"_blank">tamas.harczos@xxxxxxxx= nau.de</a>></span> wrote:<br><blockquote class=3D"gmail_quote" style=3D"= margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,20= 4,204);border-left-style:solid;padding-left:1ex">Dear List,<br> <br> while working with cochlear implants (CI) I often notice that even CI<br> listeners with very good speech perception need some extra time (in<br> comparison to normal hearing listeners) to comprehend a spoken sentence.<br= > In fact, some patients with single-sided deafness and CI in the deaf ear<br= > report a perceived latency between the normal hearing and the CI side,<br> which does not seem to be of technical nature.<br> <br> Could any of you point me to relevant literature or published studies<br> related to this phenomenon?<br> <br> Thank you!<br> Tamas<br> <span><font color=3D"#888888"><br> --<br> *~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*<br> Dipl.-Ing. Tam=C3=A1s Harczos<br> PhD Student<br> Institute for Media Technology<br> Faculty of Electr. Eng. and Inf. Techn.<br> Ilmenau University of Technology<br> Tel.: <a href=3D"tel:%2B49%203677%20467%20225" value=3D"+493677467225" targ= et=3D"_blank">+49 3677 467 225</a><br> Fax.: <a href=3D"tel:%2B49%203677%20467%204225" value=3D"+4936774674225" ta= rget=3D"_blank">+49 3677 467 4225</a><br> E-Mail: <a href=3D"javascript:_e(%7B%7D,'cvml','tamas.harczos@xxxxxxxx= tud.tu-ilmenau.de');" target=3D"_blank">tamas.harczos@xxxxxxxx= e</a><br> *~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*<br> </font></span></blockquote></div><br><br clear=3D"all"><div><br></div>-----= ----------------------<br><div><div dir=3D"ltr"><div>Nathan Barlow<br>-----= -----------------------<br></div><div>M.Sc Student</div>Discipline of Speec= h Science<br>University of Auckland<br><a href=3D"javascript:_e(%7B%7D,'= ;cvml','nbar067@xxxxxxxx');" target=3D"_blank">nbar067= @xxxxxxxx</a><br></div></div> </div></div> <br><br>-- <br><div dir=3D"ltr"><div>Nathan Barlow<br>---------------------= -------<br></div><div>M.Sc student 1002702</div>Discipline of Speech Scienc= e<br>University of Auckland<br><a href=3D"mailto:nbar067@xxxxxxxx"= target=3D"_blank">nbar067@xxxxxxxx</a><br></div><br> --001a1136b54acddb9d0509b11c65--