Effect of modified programming parameters on sound field thresholds, speech perception and CAEP among children using...

Optimizing and validating programming parameters of Thresholds(T) and most comfortable levels(C) is very important in young children using a cochlear implant who may not be able provide behavioral responses. The present study attempts to describe the changes in T/C level with behavioral and Cortical Auditory Evoked Potentials (CAEP) responses. Twenty participants using CI24RE (ST) implant with CP802 speech processor participated in the study. Three experimentally 'sham' programs were created by a) decreasing T levels, b) raising T levels or c) decreasing C levels in the 'everyday' program. Sound field thresholds and speech perception at 50dBHL were measured for all experimental and everyday programs. Acoustically evoked CAEP measures, namely thresholds for three different stimuli of/ba/,/da/and/ga/, along with amplitude and latency at 80dBnHL were recorded for all programs. The results indicated that modification of T levels did not have significant effect on CAEP threshold, latency, amplitude as also on behavioral measures of sound field thresholds and speech perception. However, reduction of C levels resulted in significantly poor sound field thresholds, speech perception as well as CAEP thresholds. Furthermore, it was found that there was a significant correlation between behavioral measures of sound field threshold and speech perception with CAEP measures. Thus, from the present study it may be concluded that behavioral and CAEP responses can be used as indicator to reflect changes in C levels resulting changes in behavioral measures in users of CP802 speech processors.