Application of auditory brainstem response (ABR) and 40 Hz auditory event related potential (40 Hz AERP) to the diagnosis of occupational noise-induced hearing impairment

Abstract

To investigate the application of auditory brainstem response (ABR) and 40 Hz auditory event related potential (40 Hz AERP) to the diagnosis of occupational noise-induced hearing impairment and to provide the evidence for diagnosis of occupational deafness. Pure tone audiometry, ABR and 40 Hz AERP were performed in 54 workers occupationally exposed to noise. The thresholds of higher frequency band, 3 kHz and 4 kHz were compared with the threshold of ABR. The thresholds of auditory frequency ban and 0.5 kHz were compared with the threshold of 40 Hz AERP. A better correlation was found between thresholds of ABR and higher frequency pure tone audiometry. There was a significant difference of thresholds between 40 kHz AERP and pure tone audiometry. The correction values of thresholds between 40 kHz AERP and pure tone audiometry in the light noise-induced hearing impairment group and the moderate noise-induced hearing impairment group were (16.43 ± 1.08) and (11.80 ± 1.12) dBn HL, respectively. In diagnosis of occupational noise-induced hearing impairment, the threshold of ABR can be used to estimate the hearing threshold of pure noise higher frequency. Because there is the significant difference of the thresholds between pure tone audiometry and 40 Hz AERP, the response threshold can not be served as the audiometry threshold, and the behavioral hearing thresholds can only be obtained by adjusting the response threshold with respective correction value.