Comparison of ABR Thresholds Using Linear Versus Blackman Gating Functions for Predicting Pure Tone Thresholds in Hearing-Impaired Subjects

Abstract

This study compared auditory brainstem response (ABR) thresholds using linear versus Blackman gating functions for predicting pure tone thresholds in subjects with sensorineural hearing losses. Twenty-six subjects with gradually-to-steeply sloping hearing loss were tested with 500, 1000, 2000 and/or 4000 Hz tone bursts. The total stimulus durations were 3 msec for both gating functions. No statistically significant mean differences were found between ABR thresholds for the linear and Blackman tone bursts at any frequency. Linear regression equations were used to describe the relationship between ABR thresholds in dB nHL and pure tone thresholds in dB HL. Standard errors of estimate of about 11 dB were obtained at 500 and 1000 Hz for both tone bursts. At 2000 and 4000 Hz, standard errors of about 6 dB were observed for both the linear and Blackman tone bursts. These data suggest that 500 and 1000 Hz tone bursts can predict pure tone thresholds within 16 dB in approximately 85% of the cases, and that the 2000 and 4000 Hz tone bursts can predict pure tone thresholds within 9 dB in approximately 85% of the cases.