Behavioural and Electroacoustic Calibration of Air-conducted Click and Toneburst Auditory Brainstem Response Stimuli

Although auditory brainstem response (ABR) audiometry is widely used to assess hearing sensitivity in infants and young children, normal calibration values vary across clinics. This study was undertaken to determine normal hearing thresholds for tonebursts and clicks with insert earphones. Techniques for performing electroacoustic and behavioural calibration of brief ABR stimuli are described. The average insert earphone thresholds for 25 young adults with normal hearing for 500, 1000, 2000, 4000 and 8000 Hz, 2-1-2 cycle tonebursts presented at 41 per second were: 24, 20, 23, 23 and 34 dB peak to peak equivalent (ppe) SPL (re 20 Pa), respectively. Average thresholds were about 30 dB ppeSPL for 100 s clicks. Results were generally consistent with normative values reported in the literature.