Subject: Re: Cochlear implants and pitch. From: Bob Masta <masta(at)UMICH.EDU> Date: Tue, 27 Nov 2001 08:43:53 -0500Al: I'm no particular expert on implants, but I do know that there is a substantial amount of current spread. There are two basic ways that stimulation is given, either between (typically adjacent) implant electrodes or between an implant electrode and a reference (usually on the mastoid, I think). Your experiment seems to require this latter type, but either way I think that the current spread would stimulate such a wide region that you won't get a satisfying answer. And you can't just use electrodes that are farther apart, since they tend to be rather big steps in terms of the frequency span of the cochlea. (Note also that even though there may be a lot of electrodes on the implant, they are rarely all in proper position to stimulate... maybe 8 or so if you are lucky, as I recall. And they tend to be at the high-frequency basal end, since that's where the implant is inserted... the rest don't make it in.) Robert Masta tech(at)daqarta.com D A Q A R T A Data AcQuisition And Real-Time Analysis Shareware from Interstellar Research www.daqarta.com