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NHCA POSITION STATEMENT Recreational Firearm Noise March 16, 2017

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NHCA POSITION STATEMENT Recreational Firearm Noise March 16, 2017 NHCA POSITION STATEMENT Recreational Firearm Noise March 16, 2017 Michael Stewart, Deanna K. Meinke, Gregory A. Flamme, William J. Murphy, Donald S. Finan, James E. Lankford, and Stephen M. Tasko National Hearing Conservation Association (NHCA) Task Force on Prevention of Noise-Induced Hearing Loss from Firearm Noise This document was prepared by The National Hearing Conservation Association (NHCA) Task Force on Prevention of Noise- Induced Hearing Loss from Firearm Noise and approved by the NHCA Executive Council, March 16, 2017. The judgments expressed here represent the best available evidence at the time of publication and shall be considered the position of NHCA and not the individual opinions of the contributing authors or their respective institutions. The contributing authors declare no conflict of interest. EXECUTIVE SUMMARY Recreational firearm use is a popular leisure-time activity in the United States today. Millions of Americans of all ages enjoy shooting sports including target practice, competitive shooting, and hunting. While participation in the shooting sports can be an enjoyable recreational pursuit, it can also put an individual at risk for noise-induced hearing loss (NIHL) and tinnitus resulting from unprotected exposure to high- intensity firearm noise. Almost all firearms generate impulse levels in excess of 140 dB peak SPL. Hearing loss may occur gradually over time due to repeated unprotected exposure to firearm noise. Hearing loss also may occur suddenly due to acoustic trauma from a single unprotected gunshot. The hearing loss is often characterized by normal or near normal hearing sensitivity in the lower frequency range with severely impaired hearing in the higher frequency range which results in difficulty hearing speech clearly. NHCA developed this guidance document to assist hearing conservationists, audiologists, physicians and other hearing conservation professionals, in managing and mitigating the risk of NIHL associated with recreational firearm noise. Several strategies can be employed to reduce the risk of acquiring NIHL and associated tinnitus from firearm noise exposure. These include wearing hearing protection devices (HPDs), using firearms equipped with suppressors, choosing smaller caliber firearms, using subsonic ammunition, shooting in a non-reverberant environment, and avoiding shooting in groups. In addition, several commercially-available HPDs are specifically designed for the shooting sports. These include conventional passive earmuffs and earplugs, level-dependent devices that attenuate high level sound while providing audibility for lower level sound, and electronic devices that amplify low level sounds and attenuate high level hazardous sounds. The key to preventing NIHL and tinnitus secondary to excessive firearm noise exposure is to educate firearm users about the auditory hazard associated with firearm noise and provide them with strategies to protect their hearing. Educational programs may be offered through hunter safety courses, hunting clubs, or during training. A special firearm noise topic section should be included in occupational educational training for individuals who use firearms as part of their jobs. Finally, clinical audiologists should educate their patients who use firearms regarding the hazards and ways to prevent hearing loss. Several educational tools are available on the National Hearing Conservation Association website including a hearing loss simulator, a tinnitus simulator, posters and slides of inner ear structures damaged by firearm noise, a hearing protection brochure, a hunting and hearing video and links to other educational resources. Firearm NIHL is almost completely preventable if necessary precautions are taken. 1 NHCA Position Statement: Recreational Firearm Noise (2017) NHCA POSITION STATEMENT RECREATIONAL FIREARM NOISE Michael Stewart, Deanna K. Meinke, Gregory A. Flamme, William J. Murphy, Donald S. Finan, James E. Lankford, and Stephen M. Tasko National Hearing Conservation Association (NHCA) Task Force on Prevention of Noise-Induced Hearing Loss from Firearm Noise This document was prepared by The National Hearing Conservation Association (NHCA) Task Force on Prevention of Noise- Induced Hearing Loss from Firearm Noise and approved by the NHCA Executive Council, March 16, 2017. The judgments expressed here represent the best available evidence at the time of publication and shall be considered the position of NHCA and not the individual opinions of the contributing authors or their respective institutions. The contributing authors declare no conflict of interest. Abstract Recreational firearm use is a popular leisure-time activity in the United States enjoyed by millions of individuals across all age groups. Recreational firearms produce impulse noise levels that exceed 140 decibels peak sound pressure levels (dB peak SPL). Unprotected ear exposure to this high-level impulse noise can cause immediate and irreversible damage to delicate inner ear structures of both the shooter and bystanders in close proximity. This damage includes noise-induced hearing loss (NIHL) and tinnitus. The potential increased risk of NIHL and tinnitus associated with recreational firearms noise may not be evident to recreational shooters, or nearby bystanders such as instructors and spectators. NHCA developed this guidance document to assist hearing conservationists, audiologists, physicians and other hearing conservation professionals, in managing and mitigating the risk of NIHL associated with recreational firearm noise. Recreational Firearm Prevalence in the United States Recreational firearm use by civilians is prevalent in the United States. Americans own an estimated 270- 310 million firearms (Jütersonke et al., 2007; Krouse, 2012), more than any other country in the world. Data collected by the U.S. Fish and Wildlife Service (2011) revealed that approximately 15.7 million individuals over the age of 16 years used several types of firearms (rifles, shotguns, pistols, muzzle loaders) for hunting purposes while approximately 7.1 million people participated in target shooting in preparation for hunting. According to the National Shooting Sports Foundation (2009), over 30 million Americans are actively involved in the shooting sports. Several states allow children 10 years of age and younger to use firearms for hunting when accompanied by an adult family member (National Shooting Sports Foundation, 2010). Recreational Firearm Noise Sound Pressure Levels Although firearms are used by millions of U.S. citizens for recreational activities related to the shooting sports, these individuals may not be aware that exposure to high-level firearm noise can be hazardous to their hearing. This need for awareness also extends to those that are exposed as nearby bystanders, e.g. instructors, spectators. Almost all firearms generate peak impulse noise levels that exceed the 140 decibel peak sound pressure level (dB peak SPL) exposure limit mandated by the Occupational Safety and Health Administration (OSHA. 1983) and the A-weighted 140 decibel (dBA) limit recommended by the National Institute for Occupational Safety and Health (NIOSH, 1998) for adults in occupational settings. The World 2 NHCA Position Statement: Recreational Firearm Noise (2017) Health Organization (WHO, 1997) recommends a 120 dB peak SPL maximum exposure limit for children. Several studies involving the measurement of firearm noise have found levels between 160 and 170 dB peak SPL for big bore rifles, pistols, and shotguns (Murphy and Tubbs, 2007; Flamme et al., 2009; Schulz, Murphy, Flamme 2013; and Meinke et al., 2014). Additionally, Meinke et al., (2013) found that some models of starter pistols can generate impulse levels exceeding 160 dB peak SPL at the shooters’ ears. Many large bore firearms that generate peak noise levels above 160 dB peak SPL at the shooters’ ear, closest to the muzzle, result in maximum permissible exposures (MPEs) of less than one shot when applying an A- weighted 8-hour equivalent energy level, LAeq8, and a limit of 85 dBA (Meinke et al., 2014). Flamme et al., (2011) employed three different damage risk criteria (DRC) and also calculated MPEs of one or less for a variety of large bore rifles and shotguns at the bystander position (1 meter behind the shooter). In addition, some air rifles have been found to exceed the 120 dB peak SPL limit for children (Lankford et al., 2016). Despite the recognition that firearms, including air rifles, can produce hazardous sound levels that can permanently damage the auditory system, 38% of target shooters and 95% of hunters reported never wearing hearing protection while shooting when asked about the previous year (Nondahl et al., 2000). Recreational Firearm Noise-induced Hearing Loss and Tinnitus High-level impulse noise generated by recreational firearms is one of the leading causes of NIHL in the U.S. today. Several studies have found recreational firearm use can lead to NIHL (Prosser et al., 1988; Dancer et al., 1991; Kryter, 1991; Cox and Ford, 1995; Stewart et al., 2001; Stewart et al., 2002). Nondahl et al., (2000) reported that the risk of having a significant high-frequency hearing loss increased by 7% for every 5 years the study participants had hunted. The audiometric configuration of firearm NIHL is characterized by normal or near normal hearing sensitivity in the lower frequencies with a precipitous drop in the higher frequencies. Affected individuals often deny their hearing loss because they can easily hear the higher
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