[Audiological basis of continuing to wear hearing aids in the contralateral ear of young children after cochlear implantation].

Objective: To study the accuracy of preoperative-ASSR in predicting behavioral thresholds of children at low age with profound hearing loss and to evaluate the feasibility of using hearing aids in non-operating ear after the cochlear implantation. Method: Children aged less than 2 years old at the time of surgery were selected as study subjects.The preoperative ASSR response threshold in 0.5, 1.0, 2.0 and 4.0 kHz were recorded.The play audiometry test was used to get the non operative ear behavioral thresholds of the children after three years old. Altogether 179 children with good cooperation and reliable results were enrolled in this study. The results of behavioral thresholds were made a comparison with the results of ASSR response threshold with corresponding frequency before operation for statistical analysis. Result: The behavioral threshold is better than corresponding ASSR response threshold with significant differences( P <0.01). Prediction rates of ASSR response threshold corresponding to behavioral thresholds from 0.5 kHz to 4.0 kHz are 49.7%, 70.9%, 59.2% and 60.9%.There are cases at all frequencies where ASSR showed no reaction but a behavioral thresholds were detected. The proportions of undrawn ASSR reaction at each frequency were 83.3%,75.5%,64.9%,45.1%. Conclusion: In profound hearing loss, the deviation between preoperative ASSR response thresholds and postoperative behavioral thresholds exists, especially in low frequency. No ASSR reaction in clinic cannot represent that there is no measurable hearing threshold. We suggest children at low age continue to wear hearing aids in the non operative ear after cochlear implantation. Whether to give up hearing aids should be judged after gaining the behavioral audiometry to avoid missing the bimodal opportunity.