Subject: Re: Cochlear implants and pitch. From: Matthew Flax <flatmax(at)CSE.UNSW.EDU.AU> Date: Wed, 28 Nov 2001 01:35:17 +1100On 27 November 2001, Bob Masta wrote: > Al: > > 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. I have heard this too - about the current spread. Perhaps it would be possible however to stimulate adjacent electrodes in quick succession ? Neural response/firing might still be active in the first bassilar section when the second bassilar section begins to fire ? > 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.) I'm sure this depends on the implant and the skill of the surgeon, but I am no expert either ! > 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 -- Matt For electronic musicians ... Vector Bass : http://mffmvectorbass.sourceforge.net/ For developers ... 3D Audio Library : http://mffm3daudiolib.sourceforge.net/ Multimedia Time Code : http://mffmtimecode.sourceforge.net/