Audiometric "early flags" for occupational hearing loss

Abstract

OBJECTIVE: OSHA criteria for recording occupational noise-induced hearing loss (NIHL) do not ensure early detection, yet scientific consensus is lacking regarding optimal "early flags" for NIHL. This study compares early flag metrics to the subsequent development of recordable hearing loss. METHODS: In a longitudinal analysis of industrial audiograms, we calculated time from flag event to recordable hearing loss as well as 10 year risk of recordable hearing loss following flag occurrence. RESULTS: The 10 dB non-age-corrected STS and the 8 dB age-corrected shift at 2, 3, and 4 kHz optimally combined positive predictive value and length of time to recordable hearing loss. CONCLUSIONS: Professionals supervising audiometric surveillance must balance predictive value of early flags with timeliness of detection. This study provides a framework for validation and selection of audiometric early flags in hearing conservation settings. ©2007The American College of Occupational and Environmental Medicine.