Leveraging cluster analysis to compare click and chirp-evoked auditory brainstem responses

The Auditory Brainstem Response (ABR) can be recorded by presenting short-duration click and chirp stimuli. The ABR test is commonly used for threshold estimation and to examine auditory brainstem integrity. The neural integrity is evaluated at suprathreshold levels. This study aimed to compare click and CE-Chirp®-evoked ABRs recorded at suprathreshold levels in normal-hearing infants and adults, using cluster analysis to identify patterns and distinctions between responses to the two stimuli.

Click-evoked and CE-Chirp® evoked ABRs were recorded from infants and adults with normal hearing at suprathreshold levels. Cluster analysis techniques examined and categorized response patterns for each stimulus type, comparing across time, frequency and time-frequency domains.

Our findings indicate a noticeable homogeneity in the click-evoked ABRs in both groups in the time-domain, suggesting a consistent response to click stimuli. In contrast, CE-Chirp®-evoked ABRs exhibited variability in both groups, which may be attributable to the complex nature of the CE-Chirp® stimulus and its interaction with the auditory system.

The implications of these findings are significant for audiologists. It is crucial to take into account the inherent variability of these responses when interpreting chirp-evoked ABRs, as they may reflect nuanced aspects of auditory system function that are not as prominent in the more uniform click-evoked ABRs. The insights from this study enhance our understanding of auditory brainstem processing and have the potential to refine the clinical protocols for ABR testing.