Methods of measuring auditory evoked potentials to unravel hearing difficulties in school-age children

Background: Detecting interaural time differences (ITD) supports sound localization and speech understanding in daily environments. ITD processing may be compromised in children with early otitis media (OM), despite normal audiograms. Psychoacoustic measures depend on behavior and are influenced by attention. AEPs provide a valuable alternative, especially for young or hard-to-test populations. In this study, we used AEPs to assess ITD sensitivity in school-age children without OM history. In this way, we obtained normative data that can be used to investigate ITD sensitivity in children with such a history.
Methods: Sixty normal-hearing children aged 6-12 years with no more than two OM episodes were recruited. The AEP stimulus consisted of an amplitude-modulated bandpass-filtered noise (900-Hz bandwidth, centered at 550-Hz) with an ITD that periodically changed between 0 ms and a fixed ITD (0.2, 0.4, or 0.8-ms). Data analysis focused on neural response patterns elicited by the changes in ITD. EEG analysis was performed using pEEGy.
Results: Data collection is currently ongoing. Data from the first nine children demonstrate that robust responses can be obtained. Preliminary analyses indicate that—unlike in adults—the responses in children do not consistently grow with increasing ITD.
Conclusion: Preliminary data show that AEP to changes in ITD can be obtained from school-age children. The full dataset, which is expected to be available in spring, will allow us to (1) establish a normative dataset and (2) investigate whether differences in response patterns between adults and children can be explained based on maturation.