Role of Extended High-Frequency Audiometry in the Early Diagnosis of Occupational Hearing Loss

Background and Aim: Occupational hearing loss is an issue with important socioeconomic and psychological extensions. Early diagnosis and application of effective preventive measures are currently limited by the lack of widely accepted screening protocols. This study was aimed at investigating the role of extended high-frequency audiometry in the early diagnosis of occupational hearing loss.

Material and Methods: Extended high-frequency audiometry thresholds were obtained from 98 workers in an industry where noise levels were measured at 90–95 dBA. Hearing threshold results were analyzed in terms of the workers' ages and the number of years they have been working in this noisy environment.

Results: Multiple linear logistic regression analysis revealed that after the appropriate correction for age, the duration of the exposure in a noisy environment was associated with significant changes in extended high-frequency thresholds (12,500–16,000 Hz) only in the group of workers who had been employed for less than 10 years. In the groups who had been employed for 10–30 years, the extended high-frequency thresholds demonstrated no significant association with the duration of employment.

Conclusions: Extended high-frequency audiometry seems to be a sensitive indicator of the early changes that occur as a result of working in a noisy environment only when applied to younger workers. On the contrary, pure tone audiometry seems more appropriate when screening persons of older age who have been working under conditions of extensive noise for more than 10 years.