The relationship between frequency specific auditory brainstem response thresholds and behavioural audiometric thresholds in hearing impaired adults

Auditory brainstem response (ABR) thresholds to masked tone pip stimuli, were obtained for 3 groups of hearing impaired subjects. Using high pass noise at 500 Hz and notched noise at 1,2, and 4 kHz, ABR thresholds in low frequency, high frequency, and flat cochlear losses were compared to conventional pure tone audiometric thresholds.A strong positive relationship, with no systematic effects of either impairment group or frequency, was found between ABR (re: laboratory norms) and behavioural (re:0dB HL) threshold elevation, though absolute ABR thresholds (dB peSPL) at 500 Hz were significantly higher than those at other frequencies. Regression analyses of the data indicated a strong but variable linear relationship between ABR and behavioural measures.The results of this study indicate that frequency specific ABR testing can provide an approximation of both the degree and the configuration of cochlear hearing losses in adults.Further refinements of both the testing and judging procedures are needed however, to reduce the variation evident in our results, and thus achieve the accuracy required for most clinical applications