Air- and Bone-conducted Brainstem Evoked Response Audiometry, collection of normative data for the new-developed level-specific CE-chirp stimulus in normal-hearing adults.
The LS CE-chirp stimulus attempts to compensate for the cochlear travelling wave delay and the change in latency with frequency per intensity. The aim of this study is to evaluate the suitability of the LS CE-chirp for air-conduction (AC) and bone-conduction (BC) ABR measurements. This study focuses on the latency for the AC and BC broadband (BB) and four different narrowband (NB) LS CE-chirp evoked ABRs. Broadband and narrowband LS CE-chirp evoked AC and BC ABRs are recorded in 50 normal-hearing young adults (25 females, 25 males). AC ABR measurements are performed at 40, 70 and 90 dB nHL and BC ABR at 40 dB nHL only. Stimuli are presented in both condensation and rarefaction polarity. Results: BB and NB LS CE-chirps show similar latencies within one transduction method and one intensity. This indicates that the latency changes with frequency defined per intensity in the model of the LS CE-chirp are an adequate compensation for the cochlear travelling wave delay. Between transduction methods, significant differences in latency are found. Furthermore, significant differences in latency are found between the 40, 70 and 90 dB nHL conditions for each chirp except the NB 2k LS CE-chirp. Moreover, results show relatively good agreement between the objective and subjective measures of BC hearing threshold.
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