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

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. Selfperception
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.