lecture 17: CIs & implantable devices - exam 3 Flashcards
what does a CI do / how is it different from HA
bypasses damaged hair cells to stimulate AN directly using electrical signals
HA amplifies sound for better acoustic hearing
CI vs acoustic hearing freq enconding
uses electrodes to stimulate different regions of the cochlea for freq perception
acoustic hearing - relies on hair cells activation along BM
CI vs acoustic hearing intensity encoding
CI - encodes intensity by varying electrical current levels
acoustic hearing - uses hair cells activity & mechanical vibrations
external components of a cochlear implant
microphone
speech processor
transmitter coil
internal components of a cochlear implant
receiver-stimulator
electrode array
where is the electrode array
placed in the scala tympani
are all electrode arrays the same length & do they have the same # of electrodes
no
vary in length & # of electrodes depending on device & manufacturer
how do CIs process speech
by converting sound into digital signals
transformed into electrical stimulation patterns for the AN
what are coding strategies
determine how sound is analyzed & converted into electrical stimulation patterns
how are CIs limited in the info they can provide
limited in conveying fine temporal & spectral details
what is CI mapping
involves programming the implant to set appropriate stimulation levels for each electrode to optimize hearing
standard adult candidacy criteria
severe to profound SNHL in both ears
limited benefit from HA
good general health
spread of excitation
when electrical stimulation from 1 electrode activates adjacent electrodes
reduced clarity & pitch perception
realistic expectations for CIs
improved speech understanding
environmental sound awareness
lip reading
realistic outcomes for Cis
vary
ability to hold conversations
