Backcountry Safety: Hearing Protection for Hunters
This article was published in the Backcountry Safety Column of the "Hunt Alaska" Magazine, Summer 2016.
Story by Jon Hunt
Finally, after days of glassing, we found three magnificent caribou on a distant bluff. Without hesitation, we planned and executed our stalk. Despite their superior vantage point, the caribou didn’t notice our approach. Just 200 yards away, in a prone position, I placed my crosshair right behind the caribou’s shoulder. Given the terrain, there was room for only two of us to shoot. Mike offered to wait closely behind. Jimmy and I each dropped our caribou on the first shot. With the remaining beast standing broadside, I quickly waved for Mike to crawl forward and get into a shooting position next to Jimmy, who was starting to glass the bluff. Mike rested in position, unaware that with the muzzle of his .300 Win Mag was just 2-3 feet away from Jimmy’s ear. In the excitement of the moment, no one noticed the obvious danger to Jimmy’s hearing. Mike fired, and Jimmy immediately rolled over in agony, clasping both hands over his ears, his head painfully pressed into the tundra as ringing and deafness overtook his right ear. Jimmy instantly experienced Tinnitus, which he later described as a 2-3 week period of constant loud ringing in his ears. After the ringing dissipated, other random sounds would induce brief episodes of ringing. Fortunately, he didn't rupture an eardrum, and his hearing recovered, but the long-term consequences are as yet unknown.
This true story of last fall’s caribou hunting incident led us to research treatment and solutions regarding our careless habit of not wearing ear protection while hunting. We are always vigilant about wearing earmuffs at the range, but have historically disregarded its significance while hunting, mainly due to our minimalist philosophy. This foolish ignorance indeed caught up with us. Let me take a moment to share what we learned this past year. Jimmy’s injury led him to Dr. Emily McMahan, Au.D., a Board Certified Doctor of Audiology, and owner of the Alaska Hearing & Tinnitus Center. She has a respectful appreciation for hunting and shooting, and graciously shared her wisdom with us on several occasions.
This article is not intended to be a dissertation on the physiology of hearing, or explain the complex logimetric scale used to determine decibels (dB) -- the measurement of sound/loudness. Rather, I hope to offer a summary of some key concepts on hearing protection that we found relevant to hunters.
Dr. McMahan is confident that, “All hunters who do not use hearing protection will eventually suffer from some degree of hearing loss.” Her logic is that a single exposure to an impulse noise of more that 120dB is enough to cause hearing loss. Even worse, noise-induced hearing loss is cumulative and permanent.
How loud is too loud?
The standard rating with which hearing protection items are labeled is called the Noise Reduction Rating (NRR). This measurement is valid primarily for an environment of “continuous” noise. This does not include “impulse” noise such as a gunshot, or construction site with random loud noises. OSHA standards state that noise exceeding 85dB for over 8 hours causes hearing loss.[i] Dr. McMahan used her Decibel Meter at my kitchen table; my kids weren’t even in the kitchen and we reached levels of 70dB. Impulse Ratings do not follow a linear formula. Many variables affect the exposure scale, such as distance from the muzzle, direction the muzzle is pointing, environmental factors (canyon, indoors), etc. There is currently no regulation mandating manufacturers of hearing protection devices to label products with an impulse rating.
What are normal noise levels?
“At 100dB it only takes 1 minute 29 seconds to begin causing damage to your ears.”[ii] 3M has an interactive website describing decibel levels of a variety of normal experiences. Keep in mind, a single exposure to an impulse noise of more that 120dB is enough to cause hearing loss.
Noise levels for firearms:[iii]
In brief, it appears that most firearms have a decibel level ranging from 140dB to 170dB. At these sound pressure levels, a single exposure without adequate hearing protection can cause immediate and permanent damage. It’s enough to make you appreciate bow hunting even more! Dr. McMahan provided me with an article from the Precision Rifle Blog that she found as a useful and accurate source for in-depth information about this topic as well as the application of suppressors and muzzle brakes. The article demonstrates that muzzle brakes drastically increase decibel levels. The more stability the muzzle brake adds to the gun, the greater the decibel level.[iv] It also compares decibel levels behind and beside the shooter. It is clearly safer to be behind the shooter rather than next to the shooter, as Jimmy will attest.
What ear protection is best for hunting?
Dr. McMahan offered a convincing solution. She appreciates the fact that hunters need to be able to hear what is happening in the environment, such as wildlife approaching, or whispers from other hunters while stalking an animal. For this purpose she suggested a custom-molded earplug be worn any time a firearm may be used. This is the earplug Jimmy now uses. It has two filters, one filters out excessive sound, and the other allows sound in. The custom Westone earplug that Jimmy purchased ($300) provides a straight noise reduction rating of 4dB. As for impulse ratings, at 132dB it offers a 15.1dB reduction. At 168dB it offers a 26.7dB reduction. This was disappointing news, until I learned about the complexity of the impulse rating and how it’s typically better than it appears. It’s important that a high-quality earmuff needs to be used in conjunction with the earplug. This combination of custom earplugs and quality earmuffs creates a safer option. NIOSH (National Institute of Occupational Safety & Health) also recommends that hunters and shooters use a dual protection method of deeply seated earplugs and earmuffs. Dr. McMahan endorses many of the 3M products, and products similar to the Howard Leight R-01526 Impact Sport Electronic Earmuff Ear Protection.
What ear protection is best at the range?
Dr. McMahan showed me an option she prefers for use at the range, when communication with others is not as important, and whispers don’t need to be understood. These fully occlusive custom earplugs offer increased hearing protection, but still should be used in addition to a quality earmuff.
How about a simple foam insert plug?
It’s clearly better than nothing. However, these are not intended for sudden noise, but rather constant noise. So, they are great for airplane travel, but less than ideal for shooting. They are not OSHA approved. One size doesn’t really fit all. Typically they don’t fitted perfectly. Be careful, the labeling may be misleading; most claim to reduce noise ranging from 22dB to 32dB, but this plug is not designed to protect against sudden impulse sounds, but rather constant noise.
In conclusion, my hope is that the reader will be more aware of the serious risk of harm to your hearing and that of those around you any time the trigger is pulled and ears are unprotected.
[i] https://www.osha.gov/Publications/OSHA3074/osha3074.html; http://www.elcaudio.com/decibel.htm