WORK-RELATED, NOISE-INDUCED HEARING-LOSS - EVALUATION INCLUDING EVOKED-POTENTIAL AUDIOMETRY

This article reviews the evaluation of 246 workers (492 ears) who unde rwent otologic and audiologic testing as part of a worker's compensati on claim for-work-related; noise-induced hearing loss. Tinnitus was pr esent in 58% of the patients, but was rarely a major symptom. Other ot ologic symptoms or a history of ear disease were virtually nonexistent . Standard audiometry showed a downsloping, high-frequency sensorineur al hearing loss in 85% of the ears tested, with only 37% having a char acteristic ''noise notch'' at 4000 or 6000 hertz. Asymmetric hearing l oss was not uncommon, with 48 patients (20%) undergoing magnetic reson ance scanning, all-of whom showed no central lesion responsible for th e loss. Proven malingering was surprisingly uncommon (9%). In this stu dy, evoked response audiometry was a valuable adjunct to confirm behav ioral thresholds in the evaluation of possible work-related, noise-ind uced hearing loss. The middle latency response was more effective than the auditory brainstem response as a result of the high-frequency ste epness of the audiometric curve.