Objective: The purpose of this fit-testing study in the field was to systematically compare three Hearing Protection Device (HPD) fit-training methods and determine whether they differ in the acquisition of HPD fitting skill and resulting amount of earplug attenuation. Design: Subjects were randomly assigned to receive HPD fit-training using one of three training methods: current, experiential HPD (eHPD), and integrated. Personal Attenuation Ratings (PARs) were acquired via HPD fit-testing and used to verify attenuations pre-and post-training. Study Sample: US Marine training recruits (n ¼ 341) identified via HPD fit-testing for remedial HPD fittraining and assigned to three cohorts. Results: The post-training HPD fittest passing rate differed by training method, with pass rates ranging from 50% (current) to nearly 92% (eHPD). The difference between group delta PAR values were significantly higher (>9 dB) in both the eHPD and integrated methods compared to the current method. Conclusion: The HPD fit-training methods that teach "what right feels like" (eHPD and integrated) provided a greater number of trainees with the skill to achieve noise attenuation values required for impulse noise exposures encountered during basic training. The attenuation achieved by those methods was significantly greater than the current training method.

Objectives To investigate the change in hearing and perceived comfort over 1 year related to using an active hearing protection device (HPD) among United States Marine Corps (USMC) personnel routinely exposed to hazardous noise. Methods USMC Weapons Instructors (n = 127) were issued an active earmuff that met military standards and was compatible with other protective equipment. These participants completed pre- and post-hearing tests and comfort surveys. A control cohort (n = 94) was also included to compare individual changes in high-frequency pure tone average (HF-PTA) over 1 year. Results The control group’s HF-PTA was 3 dB worse than the intervention group after only 1 year. Survey responses revealed perceived improvements in the ability to hear and understand, situational awareness, and safety. Conclusions Active HPDs can reduce hearing loss and improve hearing-related occupational tasks.

Introduction One challenge clinicians face is determining when a military Service Member (SM) can return to duty after an injury that affects the postural control. The gold standard to measure postural control is the Sensory Organization Test (SOT). This test measures the amount of sway present in an individual’s static stance that may be used to examine range of function and monitor recovery from injury. Normative values currently available were developed using a sample of clinically normal adults from the general population (i.e., civilian non-aviator). Previous research suggests that these values should not be used as a comparative cohort for high-performing populations in the military. However, normative values, specific to military SMs, do not exist. The aim of this study was to develop a normative clinical database for functional balance (i.e., the SOT) for military-trained aviators, an occupational specialty that may consist of high performers. Materials and Methods Forty-three U.S. Army trained aviators, between 23 and 40 years old with medical clearance for flight operations from the Fort Rucker, Alabama area community consented and participated in this study. The SOT was delivered using the NeuroCom SMART EquiTest Clinical Research System with the Data Acquisition Toolkit (version 9.3). Results A statistically significant (p < 0.01) difference between the study cohort of Army-trained aviators and the publically available general civilian normative values was found for the more challenging conditions, in which the force plate was not fixed (i.e., conditions four through six). The study cohort of Army-trained aviators were found to have a higher equilibrium score in each of these three conditions. Similarly, a significant difference (p < 0.01) between the two cohorts was found on the visual and vestibular sensory analysis ratios, and the visual preference scores (i.e., greater reliance upon visual information in the maintenance of balance). The study cohort were found to have a higher ratios (i.e., greater dependence upon these sensory cues) in each of these conditions. Conclusion Army-trained aviators are high-functioning performers whose SOT scores differ from that of the general civilian population, particularly for the more challenging test conditions. New normative values were developed from this study population. Use of the developed normative values could be used as a comparative cohort in screening aviators who are recovering from injuries that affect postural stability.

National and international regulatory and consensus standards setting bodies have previously proposed derating hearing protector ratings to provide a better match between ratings determined in a laboratory and the real-world measurements of attenuation for workers. The National Institute for Occupational Safety and Health has proposed a derating scheme that depends upon the type of protector. This paper examines four real-world studies where personal attenuation ratings (PARs) were measured at least twice, before and after an intervention in earplug fitting techniques. Results from these studies indicate that individualized earplug fitting training dramatically improves a worker’s achieved PAR value. Additionally, derating schemes fail to accurately predict the majority of achieved PARs. Because hearing protector fit testing systems are now readily available for use in the workplace, personal attenuation ratings provide a better estimate of worker noise exposures and are able to identify those persons who need additional instruction in fitting hearing protection devices.

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