An audiometric test battery for the evaluation of occupational exposure to industrial solvents

Subjects exposed to various industrial solvents were evaluated with a test battery comprising both peripheral and central auditory tests. After otoscopy, all subjects underwent the following audiometric procedures: air- and bone-conduction in the conventional frequency range, air-conduction in the extended high-frequency range, speech recognition score, low-pass filtered speech recognition, stapedius reflex threshold, stapedius reflex decay, auditory brainstem response, and cognitive event-related responses. Apart from mild to moderate sensorineural hearing loss found in some of the subjects, the peripheral tests were normal in most subjects. The central tests (filtered speech and cognitive responses) showed varying degrees of abnormality which may reflect different levels of disease in this group of subjects.