Assessment of outcome measures after audiological computer-based auditory training in cochlear implant children

To validate the clinical use of acoustic change complex (ACC) as an objective outcome measure of auditory training in Egyptian cochlear implant (CI) children and explore how far electrophysiological measures could be correlated to behavioral measures in assessing training outcome. Also to explore the efficacy of computer-based auditory training programs (CBATP) in the rehabilitation process of CI children.

Sixty Arabic speaking children participated in the present study. Forty children using monaural CI device served as study group (20 children in subgroup A and 20 children in subgroup B). Both subgroups received traditional speech therapy sessions, additionally subgroup (A) children received computer-based auditory training program (CBATP) at home for three months. Their age ranged from 8 to 17 years. 20 age and sex-matched normal hearing children served as control group as a standardization for the stimuli used to elicit ACC. The study group children were subjected to detailed history taking, parent reported questionnaire (MAIS, Arabic version), aided sound field evaluation, psychophysical evaluation using auditory fusion test (AFT), speech perception testing according to language age, ACC in response to gaps in 1000 Hz tones and language evaluation. This work-up was repeated after 3&6 months for both study subgroups.

Children of study subgroup (A) showed improvement of auditory fusion test (AFT) thresholds at 3 & 6 months post-training follow up. As regards acoustic change complex (ACC), it can be detected in 85% of subgroup (A) children, 85% of subgroup (B) children and 100% of control group children. Lower ACC gap detection thresholds were obtained only after 3 months in subgroup (A), while after 6 months in subgroup (B). There were statistically significant differences between initial assessment and 3 & 6 months follow up as regards ACC P1 and N2 latencies and amplitudes in both study subgroups, however in subgroup (A), ACC P1 amplitude at 6 months post-training was significantly larger than values of 3 months follow up. There was highly significant correlation between thresholds of AFT and ACC gap detection threshold.

ACC can be used as a reliable tool for evaluating auditory training outcome in CI children. ACC gap detection threshold can predict psychophysical temporal resolution after auditory training in difficult to test population. CBATP is an easy and accessible method which may be effective in improving CI outcome.