CORTICAL AUDITORY EVOKED POTENTIALS (CAEPS) IN CHILDREN WITH COCHLEAR IMPLANT AND CHILDREN WITH NORMAL HEARING

Mukari SZ (1), Umat C (1), Chan SC (1), Zakaria MN (2), Mohd Yusoff N (1), Ali A (1).

(1) Dept of Audiology and Speech Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia; (2) Dept of Audiology & Speech Pathology, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia.

This study compared the CAEPs in children with cochlear implant and normal hearing children. Subjects consisted of 41 children with cochlear implant aged between 4 to 12 years old (26 with good speech perception performance and 15 with poor performance) and 26 age-matched normal hearing children. CAEPs were measured using oddball paradigm with 1000 Hz pure tone and /ba/ as frequent stimuli and 2000 Hz tone and /bu/ as target stimuli. The morphology, latency and amplitude of P1, N1, P2, N2 and P300 were recorded using ipsilateral stimulation for children with cochlear implant and using right monaural stimulation for normal hearing children. In pure tone stimulation, the three subject groups did not show any significant differences in waveform morphology, latency and amplitude of the measured waves. CAEPs measured using speech stimuli revealed that cochlear implanted children with poor performance had significantly lower frequency of occurrences of P1 and N1 compared to the other two groups (p<0.05). Cochlear implant subjects with good performance showed a significantly larger P1 amplitude but a significantly smaller N1 than the other two groups (p<0.05). There was no significant difference in latencies of all the waves between the three subject groups (p>0.05). Within-group comparisons for type of stimuli demonstrated that cochlear implanted children with poor performance had significantly larger amplitude of P300 when stimulated using pure tone compared to when using speech stimuli (p<0.05). These findings suggest that CAEPs measured using speech stimuli are more sensitive in differentiating between cochlear implant subjects with good and poor speech perception performance.

E-mail: szmais@medic.ukm.my