Comparison of pure tone audiometry and auditory steady-state responses in subjects with normal hearing and hearing loss

The objective of this study is to compare pure tone audiometry and auditory steady-state response (ASSR) thresholds in normal hearing (NH) subjects and subjects with hearing loss. This study involved 23 NH adults and 38 adults with hearing loss (HI). After detection of behavioral thresholds (BHT) with pure tone audiometry, each subject was tested for ASSR responses in the same day. Only one ear was tested for each subject. The mean pure tone average was 9 ± 4 dB for NH group and 57 ± 14 for HI group. There was a very strong correlation between BHT and ASSR measurements in HI group. However, the correlation was weaker in the NH group. The mean differences of pure tone average of four frequencies (0.5, 1, 2, and 4 kHz) and ASSR threshold average of same frequencies were 13 ± 6 dB in NH group and 7 ± 5 dB in HI group and the difference was significant (P = 0.01). It was found that 86% of threshold difference values were less than 20 dB in NH group and 92% of threshold difference values were less than 20 dB in HI group. In conclusion, ASSR thresholds can be used to predict the configuration of pure tone audiometry. Results are more accurate in HI group than NH group. Although ASSR can be used in cochlear implant decision-making process, findings do not permit the utilization of the test for medico-legal reasons.