Adults with Auditory Neuropathy: Comparison of Auditory Steady-State Response and Pure-Tone Audiometry

Background: The relation between the auditory steady-state response (ASSR) and behavioral audiometric thresholds requires further clarification in the case of adults with auditory neuropathy/auditory dys-synchrony (AN/AD). Purpose: The aim of this study was to compare pure-tone audiometric threshold (PTAT) and ASSR in adults with AN/AD. Study Sample: Sixteen adult participants (32 ears) with AN/AD, ranging in age from 14 to 34 years. Data Collection and Analysis: PTAT and ASSR with high-rate stimulus modulation were measured at four octave frequencies, 500, 1000, 2000, and 4000 Hz, in each ear. The behavioral auditory thresholds were compared with ASSR estimated thresholds at each frequency. Analyses included comparison of group means and coefficients of correlation. Results: The average pure-tone thresholds revealed a moderate hearing loss in the AN/AD patients with a focus on the low frequencies. Low-frequency loss audiograms were observed in almost two-thirds of the participants. The estimated auditory thresholds measured by ASSR at all frequencies were substantially higher than the PTAT measures. There were no significant correlations between the PTAT and ASSR measurements at the 1000, 2000, and 4000 Hz frequencies (p >.05); the correlation between the two measures at 500 Hz (p =.029, r = 0.39) was weak but significant. Conclusion: There was no significant correlation between the PTAT and ASSR results at the majority of the frequencies usually tested in adults with AN/AD. Although ASSR is not a suitable method to estimate auditory thresholds in this group of patients, perhaps it can be utilized as an adjunct technique for the differential diagnosis of this disorder.