The hearing system and the ability to use it are more complicated than most people might think. Hearing is often taken for granted until people find themselves having difficulties communicating.
People often say they can hear but cannot understand what others say. There are many reasons why the ability to hear can become abnormal, but one of the most common causes of damage to the ear is through noise exposure. Gunfire is a large contributor to hearing loss. Luckily, unlike other causes of hearing loss, damage from noise exposure due to gunfire can be prevented through the use of ear protection. A variety of products are on the market that can be used for this purpose, ranging from the standard foam, over-the-counter earplugs to custom-made amplified ear protection.
The auditory system itself is complicated and delicate, and it can be divided into three sections: the outer, middle, and inner ear. Sound travels in waves through the environment to the outer ear. The outer ear directs the sound down the canal to the eardrum. The eardrum is the dividing line between the outer and middle ear. When sound enters the ear canal, the eardrum and the bones behind it vibrate, transmitting the sound through the middle ear to the inner ear. The inner ear contains the fluid-filled cochlea, which is shaped like a snail shell and contains many delicate cells. Cells in the cochlea are called hair cells and are tuned to specific frequencies. The hair cells respond to frequencies from 50–15,000 Hz (cycles per second). Hair cells turn sound into nerve impulses, which are sent to the brain to process via the auditory nerve.
There are many reasons why the ability to hear can become limited. Genetics, heredity, disease processes, medications that are toxic to the ear, the aging process, and trauma can all cause hearing loss. Damage to the auditory system can be medically treatable or permanent depending on where and how the damage occurred. Outer and middle ear damage is called a conductive hearing loss and is often treatable through medical intervention. Damage to the inner ear is a sensorineural hearing loss and is often treatable through medical intervention. Damage to the inner ear is a sensorineural hearing loss (or nerve loss). Noise exposure is the most common cause of permanent hearing loss today and can occur from various sources such as machinery, engines, music, and explosives.
Noise damage depends on several factors: how loud the sound is, the length of exposure to the sound, and whether or not the person is predisposed to hearing loss by heredity. Fortunately, two of the three factors can be controlled. Loudness plays a huge role with noise damage. Loudness levels of different sounds are measured in decibels. Fifty to 60 decibels is the approximate loudness level of normal conversational speech, 80 decibels approximates the loudness level of a busy intersection, and 130–155 decibels or greater approximates the loudness level of jet engines and gunfire. Exposure to sounds equal to or in excess of 85–90 decibels for an extended period of time is damaging to the auditory system. Thus, exposure to gunfire is well outside the safe range for hearing.
Duration is also a big factor regarding exposure to gunfire. Hearing loss can result from one-time, repeated, and/or long-term exposure to loud sounds. The more a person is exposed to gunfire, the more his or her ability to hear can be damaged.
Why is this important? Because of the shape of the cochlea and the frequency components of noise, the ability to hear in the higher frequencies will decrease first if hearing protection is not used when firing a gun. Most speech cues fall between 500–4,000 Hz, with vowels as low-pitched and consonants as high-pitched sounds. Hearing loss due to noise typically occurs around 4,000 Hz. With increased exposure, hearing sensitivity in this region will decrease and hearing loss will start to encompass neighboring frequencies. The resulting damage is permanent and affects communication abilities by limiting the audibility of consonant sounds. Often, amplification in the form of hearing aids will compensate for the hearing loss. There is also a high correlation of tinnitus, or ringing, in the ears of people with noise-induced hearing loss. Tinnitus has been reported to be very frustrating and annoying by some sufferers.
Fortunately, the effects of damage from gunfire can be prevented or greatly reduced with the use of hearing protection. Appropriate hearing protection depends on the circumstances surrounding the use of firearms, as well as the needs of the wearer. No single form of hearing protection is appropriate for every situation. A licensed audiologist is the best source for guidance in choosing appropriate hearing protection.
All hearing protection falls under two categories: earmuffs and earplugs. Both types of protection reduce the amount of loudness traveling through the ear and have varying ranges of sophistication. Earmuffs fit snuggly over the ears and are attached to a headband. Earmuffs vary in the level of complexity. Unsophisticated models are relatively inexpensive and reduce the loudness level of sound reaching the ear by insulating the ear. Sophisticated electronic models can incorporate either compression circuits that allow the loud sounds to reach the ear at a reduced loudness level, or they can have amplifiers that increase the loudness for soft sounds only. It is important to note sufficient tension must be obtained from the headband to ensure a seal is made around the ears. Many sportsmen and sportswomen find earmuffs cumbersome and uncomfortable.
The other category of hearing protection is earplugs. Earplugs also reduce the amount of loudness traveling through the ear and have a varying range of sophistication. Earplugs come in different types of materials and serve different purposes. Some are available over the counter, and others are custom-made. Regardless of the material used or the level of sophistication, all earplugs fit in the same part of the ear: the outer ear canal.
The two main types of over-the-counter earplugs are foam plugs and Sonic Valves. The major benefit of foam plugs is that they are inexpensive and can be found in most drug and grocery stores. Foam plugs, when inserted properly, are effective sources for protection against noise damage. Ear canals vary greatly in size; some are small with bends in them, and few are straight like a pencil. Because of varying canal sizes and shapes, foam plugs are often inserted incorrectly, which reduces effectiveness. Foam plugs cannot be adequately cleaned and may be uncomfortable for extended use. Foam earplugs need to be replaced routinely.
Another cover-the-counter earplug, Sonic Valves, is relatively inexpensive and can be found in sporting goods stores. Sonic Valves are popular because they enable the user to hear conversation better than with a standard solid foam plug. The Sonic Valve has an acoustic filter that is activated when loud sounds occur, blocking these sounds from entering the ear. The Sonic Valve is shaped much like a Christmas tree, enabling it to fit a variety of ear canal sizes. Again, proper insertion is key to the effectiveness of the plug. Discomfort is also a major complaint.
Custom earplugs have gained popularity with people who use firearms. Custom plugs are desirable because they provide a more comfortable fit and are easily cleaned. Custom plugs are more expensive than foam plugs and require an ear mold impression of the ear canal. To obtain optimum noise reduction, the custom plugs must fit snuggly in the ear. There are two general types of custom plugs: solid and filtered.
The solid plug is excellent for blocking damaging noise levels. Solid plugs work well for target shooting. For maximum protection, solid plugs can be used in conjunction with earmuffs, which is best for white wing dove hunting. A common complaint regarding solid custom earplugs is the diminished ability to hear speech. Filtered custom earplugs help solve some of this problem. Custom filtered earplugs are similar to Sonic Valves in function but are very comfortable to wear. Filtered plugs allow for conversation (at a reduced volume) and protect the user when loud sounds occur. Some of our patients have reported that when mowing the lawn, the mower is quiet yet they can hear approaching cars. Filtered plugs are excellent for the shooting range and all kinds of hunting environments. Filtered plugs are easy to insert, are comfortable, and provide an overall reduction of hazardous noise. For the past 28 years, we have recommended the filtered custom earplug as general, all-purpose protection for all our patients who hunt.
Amplified earplugs are the latest and most sophisticated form of hearing protection on the market. Amplified earplugs enable the user to hear everything much louder than normal except for gunfire. These plugs shut down to protect the user’s hearing when a rifle, shotgun, or handgun is discharged. Amplified earplugs are available in automatic or manual versions. Both models can be made out of soft or hard material. The benefit to the avid hunter is the increase in loudness of soft sounds, such as leaves rustling, traps releasing, animals moving, or danger approaching. Amplified earplugs also allow for conversation to be easily heard. The automatic model shuts off the amplification and blocks the sound when firearms are discharged, limiting the loudness of the noise going into the ear. The manual model has a booster switch that must be manipulated manually to increase loudness for soft sounds and must be turned off prior to firearm discharge to protect against the damaging effects of gunfire.
Amplified earplugs are a custom product and need to be molded to the shape of the ear and ear canal. Proper fit is critical for protecting the ear from the gun blast. Due to the electronics available in amplified earplugs, they can be a little pricey. The plugs are battery operated, and both models contain a manual volume control.
Firearms are used in a variety of different settings and circumstances. Regardless of the situation, it is imperative to use hearing protection any time a firearm is discharged. Not only does ear protection preserve hearing, but certain models can enhance the hunting experience. Men and women everywhere enjoy the sport of hunting wild game as well as the challenge of shooting targets. Protecting against noise-induced hearing loss does not have to reduce enjoyment received from excelling in shooting sports. Remember, anytime firearms are discharged without ear protection, whether at a target range or out in the wilderness, damage is occurring to the shooter’s hearing. Protect your hearing. It is never too late.