Comparison of ABR response amplitude, test time, and estimation of hearing threshold using frequency specific chirp and tone pip stimuli in newborns.

AbstractObjective: To evaluate the auditory brainstem response (ABR) amplitudes evoked by tone pip and narrowband chirp (NB CE-Chirp) stimuli when testing post-screening newborns and to determine the difference in estimated hearing level correction values. Design: Tests were performed with tone pips and NB CE-Chirps at 4 kHz or 1 kHz. The response amplitude, response quality (Fmp), and residual noise were compared for both stimuli. Study sample: Thirty babies (42 ears) who passed our ABR discharge criterion at 4 kHz following referral from their newborn hearing screen. Results: Overall, NB CE-Chirp responses were 64% larger than the tone pip responses, closer to those evoked by clicks. Fmp was significantly higher for NB CE-Chirps. Conclusion: It is anticipated that there could be significant reductions in test time for the same signal to noise ratio by using NB CE-Chirps when testing newborns. This effect may vary in practice and is likely to be most beneficial for babies with low amplitude ABR responses...