Performance in quiet and in noise with the Nucleus Spectra 22 and the Clarion CIS/CA cochlear implant devices.

The demographic characteristics and functional results from two cochlear implant adult patient groups are reported. The first group of subjects, implanted with the Nucleus Mini 22 Cochlear Implant System utilized the SPEAK coding strategy available in the SPECTRA 22 speech processor. The second group of subjects, implanted with the Clarion Cochlear Implant System used the CIS coding strategy with the exception of one patient utilizing the CA speech coding strategy. Data are available for 130 Nucleus subjects who were evaluated following 1 month of use of the SPEAK coding strategy. Data for the second group of subjects became available following administration of the Nucleus test battery to 38 Clarion subjects with varying implant experience. The test results presented include one common open set speech perception measure for all patients, the Freiburger monosyllabic word (FMW) tests. Additional subsequent test measures were taken from an adaptive test protocol assessing performance in quiet and quiet and two noise conditions. The results of this study conclude that both subject groups displayed similar distribution of performance scores on Freiburger Monosyllabic Words despite the large difference in group numbers. Both device groups also demonstrated a similar degree of deterioration in performance with increased background noise. This paper describes the results observed for each group.