Prevalence of permanent threshold shifts in the United States Air Force hearing conservation program by career field, 2005–2011

ABSTRACT

The purpose of this study was to describe changes in hearing, using the permanent threshold shift metric, among United States Air Force servicemembers, including active duty, Reserve and Air National Guard components, for demographics, job categories, and career fields. In the United States Air Force, only servicemembers who are occupationally exposed routinely to hazardous noise are monitored. Audiogram records and demographic variables were analyzed for servicemembers from 2005–2011 using data from the Department of Defense system that captures occupational hearing tests worldwide. Results suggest that occupational hearing loss was larger in males than females, in officers than enlisted populations, and in Reserve and Air National Guard than in active duty. Compared to similar civilian career fields, active duty has lower prevalence rates for occupational hearing loss overall, although Reserve and Air National Guard prevalence rates were more similar to the civilian reported rates. The proportion of personnel with permanent threshold shifts varied between 4.6–16.7% within active duty career fields, which includes 76% of the population for study timeframe. Permanent threshold shift was larger in small job categories, and in jobs that are not considered exposed to hazardous noise routinely which is comparative with results from civilian data analysis of occupational hearing loss. Further investigation into testing practices for Air Force specific groups, use of the system for nonoccupational hearing testing, and challenges to follow-up compliance is warranted. Increased surveillance procedures for occupational hearing loss are needed to address concerns on the prevalence of servicemember hearing loss, the role of recreational and lifestyle factors to contribute the high reported hearing loss prevalence of veterans compared to nonveterans.

KEYWORDS:

• Hearing conservation
• hearing loss
• noise
• occupational health
• public health
• military

Acknowledgments

The authors would like to thank the Epidemiology Consult Service branch members at the United States Air Force School of Aerospace Medicine for support and feedback, especially Greg Wolff and Quintin Hecht.