Pj. Abbas et al., Summary of results using the nucleus CI24M implant to record the electrically evoked compound action potential, EAR HEAR, 20(1), 1999, pp. 45-59
Objective: This study outlines a series of experiments using the neural res
ponse telemetry (NRT) system of the Nucleus CI24M cochlear implant to measu
re the electrically evoked compound action potential (EAP). The goal of thi
s investigation was to develop a protocol that allows successful recording
of the EAP in a majority of CI24M cochlear implant users.
Design: Twenty-six postlingually deafened adults participated in this study
. A series of experiments were conducted that allowed us to examine how man
ipulation of stimulation and recording parameters may affect the morphology
of the EAP recorded using the Nucleus NRT system.
Results: Results of this study show consistent responses on at least some e
lectrodes from all subjects. Cross-subject and cross electrode variations i
n both the growth of the response and the temporal refractory properties of
the response were observed. The range of stimulus and recording parameters
that can be used to record the EAP with the Nucleus NRT system is describe
d.
Conclusions: Using the protocol outlined in this study, it is possible to r
eliably record EAP responses from most subjects and for most electrodes in
Nucleus CI24M: cochlear implant users. These responses are robust and recor
ding these responses does not require that the subject sleep or remain stil
l. Based on these results, a specific protocol is proposed for measurement
of the EAP using the NRT system of the CI24M cochlear implant. Potential cl
inical implications of these results are discussed.