Auditory brainstem response to different chirp (based on cochlear partition) stimulation rates

Abstract

All through the last decades, hearing thresholds have been estimated by audiologists by different means, such as pure-tone assessments, auditory steady state response, auditory brainstem response, etc. Objective EEG-based measurements have been applied, such as the auditory brainstem response (ABR), which measures neural synchrony along the brainstem auditory pathway. Through ABR waves’ amplitude and latency due to a stimulus level, hearing thresholds can be estimated. Considered a short-latencyauditory evoked potential (1–20 ms), very short transient stimulus (0.1–10 ms) is needed to evoke ABR. Chirp is a stimulus that has demonstrated to evoke better response, compared with clicks (aprox twice responses amplitude). Chirp is a transient auditory stimulus designed that considers delay in basilar membrane tonotopic gradient inside the cochlea. Chirp auditory response has been suggested to represent higher amplitudes, lower latency and lower time to identify thresholds. Characterization of ABR morphology due to chirp stimulus is something that has still been studied since multiple chirp designs have been proposed to identify changes in response due to chirp parameters differences. In the present work a description of Chirp design and detailed ABR extraction is presented, looking for a comparison between 4 Chirp stimulation rates as described in literature.