Effect of Stimulus Rate on Click and CE-Chirp-Evoked Auditory Brainstem Responses in Infants and Adults.

PURPOSE: The purpose of the present study was to examine the effect of click and CE-Chirp stimulus rate on auditory brainstem responses (ABRs) in infants and adults. Traditional clinical measures were used to examine the responses. Also, the ABR time-frequency characteristics were explored using automated feature engineering. METHOD: ABRs were recorded from 37 infant ears and in 39 young adults. ABRs were recorded for both click and CE-Chirp stimuli at 70 dB nHL for different rates (23.3/s, 53.3/s, and 83.3/s). RESULTS: Across all rates, both click and CE-Chirp-evoked ABRs showed similar Peak I latencies in infants and adults; however, Peak III and V latencies varied. Click-evoked ABRs were earlier in latencies when compared to CE-Chirp-evoked ABRs in both groups, whereas CE-Chirp-evoked ABRs were larger in amplitude compared to click-evoked ABRs. Stimulus-type-dependent changes in the absolute ABR latencies were observed as the stimulus rate was increased. The ABR time-frequency characteristics varied with stimulus rate and were dependent on the feature extraction method applied. CONCLUSIONS: The effect of click stimulus rate on ABRs in infants and adults demonstrated in this study agrees with published literature, but our findings with the CE-Chirp do not. Audiologists and researchers should be aware of differences in ABRs due to the effect of stimulus type and rate.