Cortical auditory evoked potential (CAEP) and behavioural measures of auditory function in a child with a single-sided deafness.

OBJECTIVES

To study the changes in behavioural and cortical responses over time in a child with single-sided deafness fitted with a cochlear implant (CI).

METHODS

Cortical auditory evoked potentials (CAEPs) in noise (+5 dB signal-to-noise ratio) were recorded and auditory skills were assessed using tests of sound localization, spatial speech perception in noise, and self-ratings of auditory abilities (Listening inventory for education, LIFE and Speech, spatial and qualities of hearing questionnaire, SSQ parental version). Measures were obtained prior to and after a CI fitting, including one, six, and 12 months after the CI switch on.

RESULTS

Spatial speech recognition improved over time. At 12 months post-CI, word recognition scores were similar to those of normal hearing children. Signal-to-noise ratios for sentences decreased (i.e. improved) over time post-CI. Sound localization markedly improved at 12 months post-CI compared to baseline. Self-perception of difficulty scores decreased over time. Parental ratings of hearing abilities improved compared to baseline for all subscales. There were changes in the P1-N1-P2 complex at 12 months post-CI, which were clearer frontally across stimuli. Further research is needed to understand the significance of such changes after CI fitting for single-sided deafness.

CONCLUSION

Although the changes observed could reflect maturational changes, the clinically significant improvement in recognition of speech in noise and improved questionnaire results suggest that the CI was beneficial, consistent with the feedback from the participant.