Using the auditory steady state response to record response amplitude curves. A possible fast objective method for diagnosing dead regions.

OBJECTIVES: To assess a novel objective method of measuring response amplitude curves (RACs) using auditory steady state responses in adults.
DESIGN: RACs were recorded in 20 normal-hearing adults. The RACs were measured by recording the changes in the amplitude of the auditory steady state response in the presence of (1) swept frequency narrowband masking noise and (2) fixed narrowband masking noise.
RESULTS: The mean recorded RAC tip frequency for a 2-kHz signal was 2250 Hz for the swept masker method and 2239 Hz for the fixed masker method. The estimated repeatability coefficients, calculated using an assumed mean difference of zero, were 389 Hz for the swept method and 342 Hz for the fixed method.
CONCLUSIONS: These initial results indicate that the swept- and fixed-masking methods appear to be viable and fast ways to record RACs in normal-hearing adults. Further work is needed to further optimize the accuracy of the tip frequency estimation and to establish the normative range of tip frequencies over a wide range of test frequencies in normal-hearing and hearing-impaired subjects.