Subject: Re: [AUDITORY] RF Tx Frequencies used by CI Processors and Interference From: Sharath Chandra Ramakrishnan <looplogic@xxxxxxxx> Date: Thu, 16 Jan 2025 04:32:01 -0600--00000000000094cf08062bd04eb0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Thanks Tam=C3=A1s and others who responded off-list. Interesting that the TX frequency used (at least by Adv Bionics) corresponds to the unlicensed band (for fixed mobile units) and the adjoining HAM radio band where there are currently no known active transmissions. Regards Sharath On Wed, Jan 15, 2025 at 5:27=E2=80=AFAM Tam=C3=A1s Harczos <tamas.harczos@xxxxxxxx= mail.com> wrote: > Dear Sharath, > > You will find information about RF carriers in the excellent paper from > Fan-Gang Zeng et al., see https://doi.org/10.1109/RBME.2008.2008250 . > > Best, > Tamas > > Am 15. Januar 2025 08:26:08 schrieb Sharath Chandra Ramakrishnan < > looplogic@xxxxxxxx>: > >> Dear all >> >> I have a few questions regarding RF Tx Frequencies used by CI Processors >> and associated interference : >> >> 1. Can anyone point me to documents or know the values of radio >> frequencies used by RF transmitters of the sound processors of cochlear >> implants? I know Advanced Bionics uses 49 MHz for some of their processo= rs >> (Harmony, Neptune). What about their other processors, and what about >> Cochlear Corp and MeD-EL? This information doesn't seem to be captured i= n >> their technical manuals. >> >> 2. Have there been any studies or reports on RF interference based >> disturbances experienced by cochlear implant listeners? For instance, th= ere >> are several industrial remote control equipment, baby monitors etc >> operating specifically at and around 49 MHz. I am sure there are other >> strong RF transmissions that will show harmonics at the CI operational >> frequencies, but I am interested in interference caused by equipment >> operating specifically at the CI transmitter frequencies. >> >> 3. While the RF power itself is very low, can one completely rule out >> cross interference between CI implant listeners using the same processor >> while interacting with each other in close physical proximity ? >> >> Thanks >> Regards >> >> -- >> Sharath Chandra Ramakrishnan >> *(M.S., Ph.D.)* >> *Assistant Professor* >> University of Illinois Urbana-Champaign >> scram@xxxxxxxx >> >> <http://illinois.edu/> >> > > --=20 Sharath Chandra Ramakrishnan *(M.S., Ph.D.)* *Assistant Professor* University of Illinois Urbana-Champaign scram@xxxxxxxx <http://illinois.edu/> --00000000000094cf08062bd04eb0 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable <div dir=3D"ltr">Thanks Tam=C3=A1s and others who responded off-list.=C2=A0= <div>Interesting that the TX=C2=A0frequency=C2=A0used (at least=C2=A0by Adv= Bionics) corresponds to the unlicensed=C2=A0band (for fixed=C2=A0mobile un= its) and the adjoining HAM radio band where there are currently no known ac= tive transmissions.</div><div><br></div><div>Regards</div><div>Sharath=C2= =A0</div></div><br><div class=3D"gmail_quote gmail_quote_container"><div di= r=3D"ltr" class=3D"gmail_attr">On Wed, Jan 15, 2025 at 5:27=E2=80=AFAM Tam= =C3=A1s Harczos <<a href=3D"mailto:tamas.harczos@xxxxxxxx">tamas.harczo= s@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);padding= -left:1ex"><u></u> <div> <div dir=3D"auto"> <div dir=3D"auto">Dear Sharath,</div><div dir=3D"auto"><br></div><div dir= =3D"auto">You will find information about RF carriers in the excellent pape= r from Fan-Gang Zeng et al., see <a href=3D"https://doi.org/10.1109/RBME.20= 08.2008250" target=3D"_blank">https://doi.org/10.1109/RBME.2008.2008250</a>= .</div><div dir=3D"auto"><br></div><div dir=3D"auto">Best,=C2=A0</div><div= dir=3D"auto">Tamas</div><div dir=3D"auto"><br></div> <div id=3D"m_6912118774834354375aqm-original" style=3D"color:black"> <div> <div style=3D"color:black"> <p style=3D"color:black;font-size:10pt;font-family:sans-serif;margin:8pt 0p= x">Am 15. Januar 2025 08:26:08 schrieb Sharath Chandra Ramakrishnan <<a = href=3D"mailto:looplogic@xxxxxxxx" target=3D"_blank">looplogic@xxxxxxxx</= a>>:</p> <blockquote type=3D"cite" class=3D"gmail_quote" style=3D"margin:0px 0px 0px= 0.75ex;border-left:1px solid rgb(128,128,128);padding-left:0.75ex"> <div dir=3D"ltr"><div>Dear all</div><div><br></div><div>I have a few questi= ons regarding RF Tx Frequencies used by CI Processors and associated interf= erence :=C2=A0</div><div><br></div><div>1. Can anyone point me to documents= or know the values of radio frequencies used by RF transmitters of the sou= nd processors of cochlear implants? I know Advanced Bionics uses 49 MHz for= some of their processors (Harmony, Neptune). What about their other proces= sors, and what about Cochlear Corp and MeD-EL? This information doesn't= seem to be captured in their technical manuals.</div><div><br></div><div>2= . Have there been any studies or reports on RF interference based disturban= ces experienced by cochlear implant listeners? For instance, there are seve= ral industrial remote control equipment, baby monitors=C2=A0etc operating= =C2=A0specifically at and around 49 MHz. I am sure there are other strong R= F transmissions that will show harmonics=C2=A0at the CI operational frequen= cies, but I am interested in interference=C2=A0caused by equipment operatin= g specifically at the CI transmitter frequencies.</div><div><br></div><div>= 3. While the RF power itself is very low, can one completely rule out cross= interference=C2=A0between CI implant listeners using the same processor wh= ile interacting with each other in close physical proximity ?</div><div><br= ></div><div>Thanks</div><div>Regards</div><div><br></div><span class=3D"gma= il_signature_prefix">-- </span><br><div dir=3D"ltr" class=3D"gmail_signatur= e"><div dir=3D"ltr"><div dir=3D"ltr"><span style=3D"color:rgb(0,0,0)">Shara= th Chandra Ramakrishnan</span><br></div><div><div style=3D"border:0px;font-= stretch:inherit;font-size:12px;line-height:inherit;margin:0px;padding:0px;v= ertical-align:baseline;color:rgb(0,0,0)"><b style=3D"color:rgb(19,41,75);fo= nt-family:Calibri,sans-serif;font-size:11pt;font-style:inherit"><i>(M.S., P= h.D.)</i></b><br></div><span style=3D"border:0px;font-stretch:inherit;font-= size:11pt;line-height:inherit;font-family:Calibri,sans-serif;margin:0px;pad= ding:0px;vertical-align:baseline;color:rgb(19,41,75)"><b><i>Assistant Profe= ssor</i></b></span><br style=3D"color:rgb(0,0,0);font-size:12px"><span styl= e=3D"border:0px;font-stretch:inherit;font-size:11pt;line-height:inherit;fon= t-family:Calibri,sans-serif;margin:0px;padding:0px;vertical-align:baseline;= color:rgb(19,41,75)">University of Illinois Urbana-Champaign</span><br styl= e=3D"color:rgb(0,0,0);font-size:12px"><span style=3D"border:0px;font-stretc= h:inherit;font-size:14.6667px;line-height:inherit;font-family:Calibri,sans-= serif;margin:0px;padding:0px;vertical-align:baseline;color:rgb(0,0,0)"><a h= ref=3D"mailto:scram@xxxxxxxx" style=3D"border:0px;font:inherit;margin:0= px;padding:0px;vertical-align:baseline" target=3D"_blank">scram@xxxxxxxx= u</a></span><br style=3D"color:rgb(0,0,0);font-size:12px"><br style=3D"colo= r:rgb(0,0,0);font-size:12px"><span style=3D"border:0px;font-stretch:inherit= ;font-size:14.6667px;line-height:inherit;font-family:Calibri,sans-serif;mar= gin:0px;padding:0px;vertical-align:baseline;color:rgb(0,0,0)"><a href=3D"ht= tp://illinois.edu/" style=3D"border:0px;font:inherit;margin:0px;padding:0px= ;vertical-align:baseline" target=3D"_blank"><img src=3D"https://webtools.il= linois.edu/webservices/js/ds/signature_logog_165.png" width=3D"165" height= =3D"43" style=3D"border: 0px; font: inherit; margin: 0px; padding: 0px; ver= tical-align: baseline; color: inherit; width: 165px; height: 43px;"></a></s= pan><br style=3D"color:rgb(0,0,0);font-size:12px"></div></div></div></div> </blockquote> </div> </div> </div><div dir=3D"auto"><br></div> </div></div> </blockquote></div><div><br clear=3D"all"></div><div><br></div><span class= =3D"gmail_signature_prefix">-- </span><br><div dir=3D"ltr" class=3D"gmail_s= ignature"><div dir=3D"ltr"><div dir=3D"ltr"><span style=3D"color:rgb(0,0,0)= ">Sharath Chandra Ramakrishnan</span><br></div><div><div style=3D"border:0p= x;font-stretch:inherit;font-size:12px;line-height:inherit;margin:0px;paddin= g:0px;vertical-align:baseline;color:rgb(0,0,0)"><b style=3D"color:rgb(19,41= ,75);font-family:Calibri,sans-serif;font-size:11pt;font-style:inherit"><i>(= M.S., Ph.D.)</i></b><br></div><span style=3D"border:0px;font-stretch:inheri= t;font-size:11pt;line-height:inherit;font-family:Calibri,sans-serif;margin:= 0px;padding:0px;vertical-align:baseline;color:rgb(19,41,75)"><b><i>Assistan= t Professor</i></b></span><br style=3D"color:rgb(0,0,0);font-size:12px"><sp= an style=3D"border:0px;font-stretch:inherit;font-size:11pt;line-height:inhe= rit;font-family:Calibri,sans-serif;margin:0px;padding:0px;vertical-align:ba= seline;color:rgb(19,41,75)">University of Illinois Urbana-Champaign</span><= br style=3D"color:rgb(0,0,0);font-size:12px"><span style=3D"border:0px;font= -stretch:inherit;font-size:14.6667px;line-height:inherit;font-family:Calibr= i,sans-serif;margin:0px;padding:0px;vertical-align:baseline;color:rgb(0,0,0= )"><a href=3D"mailto:scram@xxxxxxxx" style=3D"border:0px;font:inherit;m= argin:0px;padding:0px;vertical-align:baseline" target=3D"_blank">scram@xxxxxxxx= nois.edu</a></span><br style=3D"color:rgb(0,0,0);font-size:12px"><br style= =3D"color:rgb(0,0,0);font-size:12px"><span style=3D"border:0px;font-stretch= :inherit;font-size:14.6667px;line-height:inherit;font-family:Calibri,sans-s= erif;margin:0px;padding:0px;vertical-align:baseline;color:rgb(0,0,0)"><a hr= ef=3D"http://illinois.edu/" style=3D"border:0px;font:inherit;margin:0px;pad= ding:0px;vertical-align:baseline" target=3D"_blank"><img src=3D"https://web= tools.illinois.edu/webservices/js/ds/signature_logog_165.png" width=3D"165"= height=3D"43" style=3D"border: 0px; font: inherit; margin: 0px; padding: 0= px; vertical-align: baseline; color: inherit; width: 165px; height: 43px;">= </a></span><br style=3D"color:rgb(0,0,0);font-size:12px"></div></div></div> --00000000000094cf08062bd04eb0--