Auditory brainstem response to chirp stimulus in children with moderate and severe sensorineural hearing loss

Abstract

BackgroundClick auditory brainstem response (ABR), is abrupt and rapid onset, have broad spectrum nonfrequency-specific response. ABR needs good neural synchrony, the greater number of neurons that fire results in a larger response amplitude. The application of chirp stimuli aims to produce a synchronized response from a 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.ObjectivesThe aim of this study was to correlate between pure-tone audiometry (PTA) threshold and click and chirp-ABR thresholds in children with moderate and severe sensory neural hearing loss.Patients and methodsThis study included two groups: control group (G1), which consisted of 30 children with normal peripheral hearing and study group (G2), which consisted of 60 children with moderately severe sensorineural hearing loss (SNHL).ResultsResults showed that significant correlation between chirp and behavioral PTA and between click and behavioral PTA in normal hearing and hearing-impaired children, except in severe steeping SNHL. In steeping SNHL, there was a reduced correlation between behavioral PTA and click ABR stimuli. In addition, there was a significant correlation between narrow band-chirp at 500, 1000, and 4000 Hz and behavioral PTA in normal hearing and sensory neural hearing loss in children, otherwise in severe steeping SNHL. In this category, there was a reduced the correlation between behavioral PTA and narrow band-chirp-ABR stimuli.