Auditory brainstem response to a chirp stimulus in infants with normal hearing

Abstract

Background The CE-chirp stimulus shows promising results in auditory brainstem recording. The response to broad-band CE-chirp in normal infants and comparing it with the gold standard click stimulus is needed. Objective The purposes of this study were to (a) standardize auditory brainstem responses (ABR) in infant using chirp stimuli in normal hearing infants, (b) compare them with those evoked by click stimuli, (c) determine whether chirp-evoked response is easier to detect at near threshold values, and (d) analyze the amplitude growth function of chirp-evoked ABR as a function of stimulus intensity in infants. Patients and methods A total of 50 normal infants, with age ranging from 2 to 24 months, with normal hearing were included. The following procedures were done: a medical history, otologic examinations, behavioral observation audiometry, acoustic impedance, and ABR by click and CE-chirp. Results The chirp stimulus shows higher amplitude at all intensities and shorter latencies in comparison with click at high intensity and longer at low and threshold levels. The early waves are less frequent in chirp at high intensities. Conclusion The present study provides reference CE-chirp ABR values for infants. CE-chirp evokes lower threshold than click and easier peak identification at threshold, which is particularly helpful in infants.