Objective assessment of noise-induced hearing loss : a comparison of methods

Abstract

Objective measures may be required to estimate hearing thresholds in individuals who feign hearing loss. This study compared two auditory evoked potential techniques, slow cortical auditory evoked potential (SCAEP) and auditory steady-state response (ASSR) for estimating behavioural hearing thresholds in adults exposed to occupational noise. Participants had either normal hearing (n=15), or a hearing loss with a history of occupational noise exposure (n=16). Mean differences between SCAEP and behavioural thresholds for both participant groups varied between 0 to 6 dB across 0.5, 1, 2, and 4 kHz with standard deviations of ±10 dB. The mean difference between ASSR and behavioural thresholds was larger varying between 22 to 32 dB with standard deviations of ±13 to 14 dB. Overall SCAEP correlation with behavioural thresholds was 0.85 compared to 0.75 for ASSR. Findings suggest SCAEP may be the objective measure of choice for this population but, unlike the ASSR, require interpretation of responses by experienced clinicians.