Sensitivity of CHIRP auditory brainstem response and auditory steady state response for detecting normal hearing in children

BackgroundIn recent years, great development of electrophysiological procedures for detection of hearing level in infants and children has been achieved - click auditory brainstem response (ABR), tone burst ABR, and notched noise ABR. The two most recent methods are CHIRP signal ABR and auditory steady state response (ASSR).Aim of the studyThe aim of this study was to identify the best electrophysiological method for detecting normal hearing thresholds.Patients and methodsA prospective study was conducted on 80 ears from 58 children aged from 1 to 2 years that showed normal hearing thresholds in all frequencies in visual reinforcement audiometry (VRA) cooperatively, for which CHIRP ABR and ASSR were evaluated and the results were analyzed.ResultsBoth CHIRP ABR and ASSR showed moderate correlation with VRA at 0.5 and 1 kHz and a strong correlation at 2 and 4 kHz. CHIRP ABR thresholds were closer to VRA thresholds and showed a sensitivity of 100%, detecting normal hearing thresholds at all frequencies, whereas the sensitivity of ASSR in detecting normal hearing was decreased with decreasing testing frequency, reaching a low percentage of 57.5% at 0.5 kHz.ConclusionCHIRP ABR is the best electrophysiological method for assessing hearing thresholds in children whose hearing average is expected to be close to normal threshold.