Degree Name

Doctor of Audiology

Document Type


Date Created



Occupational noise-induced hearing loss (NIHL) and tinnitus are two major health concerns that have high economic and personal costs for industrial workers in the United States. To monitor for NIHL in the workplace, employers are required to provide annual hearing tests for noise-exposed employees. Currently, workplace intervention to prevent NIHL is based upon the identification of a worsening of hearing thresholds called “significant threshold shifts” (STS) using various formulae. Few studies have inspected the temporal relationship between the self-reporting of tinnitus and the identification of noise-induced hearing shifts in workers. The only study that appeared to have examined this relationship in detail was Griest and Bishop (1998). This current study was designed to expand upon Griest and Bishop and examine the prevalence and temporal relationship between the presence of self-reported severe tinnitus and the identification of an audiometric shift indicator of a significant change in hearing thresholds— Occupational Safety and Health Association (OSHA), standard threshold shift (OSTS), OSHA STS with age correction (OSTS-A), National Institute for Occupational Safety and Health (NIOSH) STS (NSTS), and the Griest and Bishop (1998) 4kHz maximum threshold shift (4KMax), suggestive of noise-induced hearing loss. This was accomplished by analyzing a de-identified data set containing audiometric thresholds and otologic case histories including a single question asking about the presence of severe tinnitus from 146,792 industrial workers collected as part of OSHA (1983) or U.S. Mine Safety and Health Administration (1999) mandated hearing conservation programs from 1970 through 2020. The results of the temporal analysis of 1,766 workers with “severe tinnitus” indicated that with each of the four STS criteria, the STS condition was met significantly (p ≤.01) earlier than the self-report of severe tinnitus. Using the 4kMax criteria indicated the shortest mean lag time from an STS to a self-report of tinnitus, with a mean of 1.1 years, while the OSTS-A method resulted in the longest mean lag time of 2.3 years. These results underscored the existence of a temporal relationship between the development of NIHL and the onset of severe tinnitus in noise-exposed workers, which indicated a need for more tinnitus focused prevention and management in hearing conservation programs.

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