Markmanship: Hitting the Bulls Eye

Targeting Noise Induced Hearing Loss in Shooters

Hunter

The following interview of Dr. R.G. Love appeared in PRIME Magazine

by Niko Corley

1. How common is hearing loss in hunters and shooters?

Very common, almost 4 times more common than the average population. Some sources estimate that 80 % of shooting sportsmen have some degree of hearing impairment. Other bold observers state 100%.

2. What are the most common types of hearing damage for hunters and shooters and how are they caused?

One commonly overlooked cause of hearing loss for shooters is impaction of debris and cerumen, or wax, in the ear canal down onto the ear drum. Some shooters may push hearing protective plugs a bit too far into their ears or in some cases may attempt to clean out wax using cotton tips. These strategies can push the cotton fibers into the wax and move the hardening mass deeper into the ear causing an obstruction of the ear canal and a “conductive” type hearing impairment. This can frequently be corrected in an Ear Nose and Throat doctors office in a simple procedure to remove the plug of material. Some surgeons no longer recommend irrigation for wax removal as injury to the ear drum can occur in overzealous cleaning attempts. Wax softening drops may be used and in some cases they can be helpful. Candling wax cones, sometime promoted at gun shows, have not been shown with critical testing to be of real value.

Another common cause of hearing loss is Noise induced Hearing Impairment.

Because the very loud sounds from pistol, rifle and shotgun blasts can be damaging to the inner ear and can cause lasting damage to the hearing hair cells, High Frequency Noise induced hearing loss at the 4000 Hz frequency is much more common in shooters.

The sound blast released at the moment of ignition of powder in a shotgun shell or in a conventional pistol or rifle cartridge can create tremendous sound pressure energy. Just as a projectile or bullet carries destructive energy with it and conveys that to its target, the power of the blast in sound pressure also is transmitted through the air and everything nearby is affected. This type of blast sound is often classified as noise. Similarly loud sounds occur with the backfire of an engine exhaust system, with a lightning strike in a thunderstorm, and with detonation of explosive charges such as dynamite or plastique.

The damaging effects of noise were widely noticed upon the return of battle tested troops from World War II. Thereafter, significant research began to discover that noise damage could be prevented by using sound pressure barriers in hearing protective devices. Decades of research documentation can be found in the Occupational statement from the Centers for Disease Control (CDC) in June 1998 

Modern sound wave phase cancellation devices now can be coupled with sophisticated electronic compression protection instrumentation and can help to shield the wearer’s middle and inner ear from the damaging effects of blast noise.

3. Will shooting certain types of firearms or participating in certain types of hunting/shooting activities be harder on a person’s hearing than others?

Although this is commonly used as a reason for not wearing protective devices, it isn’t really true. Presuming that firearms indicate gunpowder charges, and not air blast rifles with pellets or bbs, then every pull of the trigger creates an explosion loud enough to cause permanent damage and hearing loss. Some shooters will advise that the blast of a 22 pistol or the blast of a .410 shotgun is not “as loud” as a 10 guage or a .357 or even a 7 mag rifle blast. Since any one of those alone in a single explosion, (much less a sequence of 25 bursts from shooting a box of shells), can be permanently damaging, the argument is moot. I would suggest the hairs they are splitting with such twisted logic may reside on their own inner ear hair cells.

This may explain why hunters, who believe they may only get off one or two shots in an afternoon hunt, are said to be far less likely to use hearing protection than trap and skeet shooters, or target marksmen.

4. How often should hunters and shooters wear hearing protection?

Every Time they shoot, or they observe someone else shooting from close range, and every time they operate loud noisy machinery or equipment.

Make it a point to insist on safe hearing and vision conservation in the same aggressive manner that gun safety and accident prevention is taught.

I am pleased that the training program developed by the National Rifle Association includes hearing and vision protection even with air rifle and air pistol activity.

From the NRA website, a comment on the training of a safe approach ……

Wear eye and ear protection as appropriate. Guns make sound that can cause hearing damage. Guns can also emit debris and gas that could cause eye injuries. For these reasons, shooters and spectators should wear shooting glasses and hearing protectors. The range SOPs should specify that all range users, including spectators, should wear eye and ear protection. Sound travels beyond the immediate firing point. All range users, including spectators, should also wear eye protection on air gun ranges to prevent injuries. 

Hearing protectors should always be worn. Although air rifles have a considerably reduced amount of noise pressure and pulse than do firearms, hearing protectors should be worn at all times when on the range or on the firing line to ensure that no hearing damage occurs. Hearing protection also enhances concentration on the line by reducing distracting noises during shooting.

5. What are some protective options hunters and shooters can take to preserve their hearing?

Inexpensive Foam type shooters plugs inserted into the ear, are usually a bit more effective with noise protection than inserting cotton wads. I recommend they be discarded with every use to avoid increased risk of infection.

Shooters ear muffs can be used with or without plugs for additional protection. These usually have a listed numeric dB or Decibel sound power protective rating. Some devices may provide a bit more protection than others. The ratings listed on their packaging will refer to the sound attenuation or blocking or reduction of a measure of sound power. A set of ear plugs rated to provide 6- 12 dB protection, will reduce the dB level of sound pressure power, or loudness by about 6 to 12 decibels. This small amount of protection may not be enough for very loud sounds such as a rifle muzzle blast.

For an understanding of how loud certain sounds may be visit the American Academy of Otolaryngology Head and Neck Surgery website at this linkhttp://www.entnet.org/HealthInformation/soundPower.cfm and look for the tool to teach you the power of sound.

Certain types of hearing devices may have electronics built into them to accomplish phase cancellation or counterwave sound baffling to reduce noise. Many shooters ear level devices have built in noise compression interruption.

These devices can also operate similarly to hearing aids by amplifying sounds as well and then suddenly chop out the blast noise and quickly turn amplification of sound back on to recover hearing after a blast of loud damaging noise. These are often favored by upland bird hunters and for range shooters for the added safety permitting full communication and enjoying full noise abatement and protection. Some deer hunting enthusiasts may find that they help them hear an approaching buck about 20 seconds before they would otherwise have noticed rustling noise. These devices may vary in price and some are as expensive as programmable hearing instruments, or a new shotgun or rifle.

The prices may be different in some areas. The best units require a good fit into the ear with a custom ear mold. Some are offered at Outdoor Sporting Goods stores, and others are available through Hearing Instrument Dealers and at some Ear Nose and Throat Doctors offices. Successful fitting is best done locally although some people try to save money by purchasing online or through a catalogue service. Compared to a dim light high power scope, or another new 28 gauge double barrel, the price may seem more reasonable. Compared to a new set of hearing aids every 5 years for the rest of your life, the protection now may seem quite inexpensive.

6. What are some signs of hearing damage hunters and shooters might notice?

Shooters who have forgotten their hearing and vision protection when putting their rifle in the sand bags to site in their scope, will quickly be reminded at the first blast report by the ringing in the ears and the sudden change in hearing that comes from the reflex tension of the small muscles in the middle ear trying to tighten up the ear bones or ossicles to minimize damage. These small bones can be fragile. This type of repetitive shooting, without protection can be very harmful.

Shooters who develop damage may have only a small amount at first, but more damage may gradually increase over time.

If you notice you hear but don’t understand when others are speaking, need more volume from the television or radio than others seem to need, ask others to repeat statements that you think you missed, frequently need to ask others to speak up, find that your friends, family and acquaintances are always mumbling, find that you have difficulty with telephone conversations, or  if perhaps you often    notice that you can’t understand anyone speaking near you in a noisy area you should be tested for hearing loss.

If you frequently find everyone around you  is laughing at a joke and you didn’t catch the punch line, then you probably should be evaluated for hearing loss.

You don’t wantyour hearing loss to be everyone’s punch line.

The funny thing about this is that hearing loss is much more noticeable to others than wearing hearing aids.

7. What should someone do if they suspect their hearing is damaged?

Don’t wait to seek help. Often hearing loss sufferers wait 12 months or more before seeking assistance.

Sudden hearing loss can be a true medical emergency.

Shooters who have ear pain, or sudden change in the hearing that does not recover within an hour should see an Ear Nose and Throat surgeon as soon as possible. Although a night time ER visit is probably not useful, calling the ENT medical office when the staff arrives to open and advising the doctors nurse that the hearing suddenly went away should prompt an appointment offering that day or perhaps the next day.

Based upon recent research, many ENT doctors now advise using three times a day doses of 2 Aspirin tablets and of 2 Vitamin E capsules for 48 hours after blast noise exposure such as shooting muzzle blast or other explosive sounds. This is thought to help offer some  early rescue recovery to the  the inner ear with cellular level biochemical recovery from the blast noise and thought to mitigate the lasting damage of loud sound.    Hearing testing should be scheduled  within days to determine whether other evaluation or treatment would be wise.

NOISE INDUCED HEARING IMPAIRMENT MORE FROM THE WEB

Here are several respected links that deal with the topic of noise induced hearing impairment