Effect of minimum and maximum electrical stimulation levels on sound field thresholds,and speech perception in children using the Advanced Bionics Cochlear Implant.

Background: It's crucial to study the effect of changes in thresholds (T) and most comfortable levels (M) on behavioral measurements in young children using cochlear implants. This would help the clinician with the optimization and validation of programming parameters.

Objective: The study has attempted to describe the changes in behavioral responses with modification of T and M levels.

Methods: Twenty-five participants in the age range 5 to 12 years using HR90K/HiFocus1J or HR90KAdvantage/HiFocus1J with Harmony speech processors participated in the study. A decrease in T levels, a rise in T levels, or a decrease in M levels in the everyday program were used to create experimental programs. Sound field thresholds and speech perception were measured at 50 dBHL for three experimental and everyday programs.

Conclusion: The results indicated that only reductions of M levels resulted in significantly (p<0.01) poor aided thresholds and speech perception. On the other hand, variation in T levels did not have significant changes in either sound field thresholds or speech perception. The results highlight that M levels must be correctly established in order to prevent decreased speech perception and audibility.