Objective assessment of auditory thresholds in noise-induced hearing loss using steady-state evoked potentials

The purpose of this study is to evaluate whether steady-state evoked potential (SSEP) can be used for objective estimation of auditory thresholds in patients with noise-induced hearing loss (NIHL). Eleven subjects (22 ears) with a characteristic audiometric notch between 3000 and 6000 Hz participated in this study. Both pure-tone thresholds and SSEP thresholds were obtained for each ear of all subjects. The correlation of SSEP thresholds and pure-tone thresholds was assessed. The results show that SSEP thresholds predicted pure-tone thresholds with correlation coefficients (r) of 0.86, 0.92, 0.94 and 0.95 at 500, 1000, 2000 and 4000 Hz respectively. Typically, the SSEP thresholds overestimate the pure-tone thresholds by 10-20 dB, but they closely reflect the configuration of the audiogram. The strength of the relationship between SSEP and pure-tone thresholds increased with increasing frequency and increasing degree of hearing loss. In conclusion, SSEP can be used as a reliable and objective tool to assess auditory thresholds in patients with noise-induced hearing loss with high-frequency dips.