Late Latency Potentials as Auditory Performance Indicators in Cochlear Implantees

Abstract

Aim: To assess the relationship between behavioural and electrophysiologial outcome measures between good and poor performers using bimodal hearing device. Method: Thirty Kannada-speaking bimodal cochlear implant (CI) users (age range = 4 to 8 years) participated in the study. Among these, there were 20 good performers (SIS ≥ 72%) and 10 poor performers (SIS ≤ 52%). They received CI from government schemes. Aided late latency potentials (LLR) for /da/ and /ba/ stimuli, word recognition score (WRS) test and IT-MAIS questionnaire were administered in three aided conditions viz., CI only, hearing aid (HA) only, and bimodal. Results: All the participants showed P1 and N1 peaks of LLR in CI only and bimodal conditions. The LLR was absent in the HA only condition. Results showed a significant correlation between some parameters of LLR potentials and WRS. There was a moderate correlation between the P1 latency of /ba/ and WRS in bimodal condition. Additionally, there was a lack of correlation between LLR latency and IT-MAIS scores. No significant correlation was observed between the amplitude of P1-N1 with the WRS and IT-MAIS scores. There were significant differences observed in WRS between CI only and hearing aid only, and between bimodal and hearing aid only conditions in the good performers group. Results showed no significant differences between CI only and bimodal conditions in LLR parameters within the good performers group. The results indicated a consistent and significant difference between the good and poor performer groups in all behavioral measures. The study also found specific LLR parameter differences between the two groups. Notably, there were significant differences between the groups in N1 latency for both /ba/ and /da/ sounds, as well as in P1 latency and P1-N1 amplitude for /ba/ sound in bimodal conditions. Conclusions: The CI stimulates the auditory system to facilitate the growth of speech and language abilities, and aided LLR could be an indicator of the growth.