Occupational Noise Dose Reduction via Behavior Modification Using In-Ear Dosimetry among United States Air Force Personnel Exposed to Continuous and Impulse Noise

Abstract

In-ear dosimetry and noise exposure feedback were used to modify worker attitude and behavior regarding hearing protection use. The study specifically addressed whether providing in-ear noise exposure data to workers resulted in a reduction in average noise dose rate equivalent continuous levels. Nineteen combat arms instructors (impulse noise group) and heavy equipment operators (continuous noise group) working for the United States Air Force volunteered to participate in a six-month field study using in-ear dosimeters to collect daily noise level data. Participants served as their own control group, receiving periodic noise exposure feedback reports in the latter half of the study only. The control and feedback phase noise exposure data were examined using analysis of variance for differences that could be indicative of more effective hearing protection device use. Additionally, a 7-point Likert survey was used to monitor worker attitude towards hearing protection use, and worker medical histories were examined for evidence of previous hearing loss. Overall, this research found a significant reduction in noise dose rate equivalent continuous level (-2.5 dB with p = 0.019) for the continuous noise group following periodic noise exposure feedback on in-ear noise levels. This effect was not detected at the individual level due to limited samples. No effect was detected in the impulse noise population, likely due to limitations of dosimeter technology in response to impulse noise. No correlation between worker attitudes towards hearing protection and noise dose rate equivalent continuous level was detected for either group (continuous p = 0.249; impulse p = 0.478). While workers reported that in-ear dosimeters and noise exposure feedback helped them control their exposures, few reported using immediate feedback functions to control noise exposures within a work shift. These results indicate that in-ear dosimetry and noise exposure feedback could provide an effective tool to reduce worker noise exposures over time. However, advances in dosimeter technology are necessary before it can be evaluated for impulse noise. Additionally, further research is necessary to understand the link between worker attitude and hearing protection device use.