Auditory brainstem-evoked response to chirp and click stimuli in children with moderate and severe sensorineural hearing loss

Abstract

Background Auditory brainstem response (ABR) using click stimuli enables global objective estimation of hearing threshold. The application of chirp stimuli aims to produce synchronized response from large portion of hair cells in the basilar membrane. The chirp was designed to produce simultaneous displacement maxima along the cochlear partition by compensating for frequency-dependent traveling-time differences. Objectives The study aimed to compare the response characteristic of both clicks and chirps stimuli in children. Accordingly, we compared latency and amplitude of wave V at different intensity levels and waves I and III at high levels. Moreover, we correlate between pure-tone audiometry (PTA) threshold and each of click and chirp ABR threshold in the same groups. Patients and methods This study included two groups: the control group (G1) consisted of 30 children with normal peripheral hearing. A study group (G2) consisted of 60 children with moderate to severe sensorineural hearing loss. Results The results have shown that on using chirp stimuli wave V could be detected easier with shorter latency and larger amplitude than in click ABR. On the other hand, click stimulus was better than chirp stimulus at high-intensity levels regarding identification of waves I and III. In addition, there are significant correlations between chirp and behavioral PTA. Moreover, there are significant correlations between click and behavioral PTA in normal hearing and hearing-impaired children except at severe steeping sensorineural hearing loss.