US Army hearing protection standards and soldier hearing loss prevention

¶ … United States Army

Do to Improve on Enforcing Hearing Protection Standards

To Reduce Hearing Loss Among Soldiers

Nearly one third of the close to thirty million Americans with hearing loss today can attribute their disability to what has been deemed as 'toxic noise.' With a loss of hearing, humans cannot fully function in their environments. The working surroundings are by far the biggest culprit to the problem as many Americans have lost their hearing while working in steel mills and mines. "According to OSHA enforcement policy, employers must record work-related shifts in hearing of an average of 25 dB or more at 2,000, 3,000 and 4,000 hertz in either ear. In January 2001, OSHA proposed changing this trigger for a recordable injury to 10 dB. In July, however, OSHA said it was reconsidering the change because "Congress intended the recordkeeping system to capture non-minor injuries and illnesses. OSHA is reconsidering the finding that a 10 dB shift in hearing acuity represents such a health condition." (Minter, 2002)

However, another very large percentage of those individuals who have lost their hearing have lost it while serving in the various branches of the United States Armed Forces. "Military personnel deal with so much noise that 22,000 disability claims are filed each year because of Hearing loss." (NewScientist.com news service, 2002) This report attempts to understand hearing loss and to also make suggestions regarding the United States Army's problem that revolves around the situational question of what can be done to help improve upon the ability to enforce hearing protection standards in order to reduce hearing loss among soldiers. "Localization represents a fundamental auditory skill that contributes to survival by indicating the presence and position of mates, prey, and enemies. Moreover, identification of sound source positions is an intimate part of modern-day orientation and surveillance of the environment. The ability to accurately localize and quickly identify the position of potential hazards is critical in combat and in many of today's work environments. (Vause & Grantham, 1999)

The military has been contending with this issue throughout its history and the current war in Iraq will only intensify the situation regarding soldiers suffering from hearing loss or tinnitus. Soldiers returning from the battle field feel that they are not the same in many more ways than one when they return. "Mateo wound up in Walter Reed's psych ward, where doctors diagnosed post-traumatic stress disorder. "I lost my humanity in Iraq," says Mateo, who had to pull a headless Iraqi shot by American soldiers from a truck. "I didn't come back the same." His wounds include hearing loss, shrapnel in his head and shoulder, five bulging disks on his neck, and a herniated disk in his back." (Cannon et al., 2004)

Explosions from mines and hand grenades or munitions, small arms firing, helicopter and cargo carrier travel, armored vehicle and ATV travel are just a few of the thousands of potential causes of hearing loss or tinnitus. The military must also consider causes that are from natural sources such as human born diseases and even insects bites. All of these situations could occur while soldiers are on duty - but, the military forces must also consider soldiers who are off duty? "But today, a growing source of hearing impairment is the tools and toys of recreation. Americans are pounding their ears with gas-powered leaf blowers and high-amplified stereos, with NASCAR races and 1,875-watt hair dryers, even, remarkably, with children's playthings." (Couzin & Terrell, 1999) as noted, this report attempts to understand hearing loss and its causes and to make suggestions regarding the inherent problems the United States Army's faces as they improve the ability to enforce hearing protection standards in order to reduce hearing loss among soldiers.

This report therefore attempts to understand hearing loss and to also make suggestions regarding what can be done to help improve upon the ability of enforcing hearing protection standards in order to reduce hearing loss among soldiers.

What Can the United States Army

Do to Improve on Enforcing Hearing Protection Standards

To Reduce Hearing Loss Among Soldiers

Introduction

This report attempts to understand hearing loss and to also make suggestions regarding the United States Army's issues concerning what can be done to help improve upon the ability to enforce hearing protection standards in order to reduce hearing loss among soldiers. In the civilian forum, hearing failure issues, concerns and compliance are dealt with by with the Occupational Safety and Health Administration or OSHA. The civilian environment in the United States has established hearing conservation standards that are intended to ensure that any employee is not subject to suffering from hearing loss due to his or her exposure to toxic noise in the work place. "Health and safety people are being required to justify their programs on a rolling basis in a business context, so the whole issue of just doing something for compliance and going through the motions doesn't count anymore." (Minter, 2002) of course it is often the case that hearing health experts feel that existing civilian hearing conservation standards are not meeting the needs of the employee and they therefore advocate new occupational safety and health measures for employers to focus more on prevention of hearing loss as opposed to their simply complying with existing standards.

That is all well and good for the civilian world, but there is no equivalent to the Occupational Safety and Health Administration in the military world other than existing standard operating procedures and temporary review and investigation committees. Like the civilian arena, it is crucial for the United States Army to follow the lead established by OSHA where soldiers are first educated and thus made to understand how important the ability to hear is for their lives. In the majority of the cases known, noise-induced hearing loss was preventable. Soldiers must be made to no longer take their hearing for granted and therefore recognize its overall value before it is too late and the hearing capabilities are lost. But all military branches of service must be made to recognize and understand the big picture of the problem so that the concept and related ideas of hearing loss prevention can be circulated through the ranks from the highest General to the lowest private.

The upper echelon of ranking officials must be privy to the overall cost associated with hearing loss and lost communication as well as the other safety risk factors soldiers face once they have lost their ability to consciously hear. "Noise-induced hearing loss is a significant unmet socioeconomic problem in industrial societies. It is estimated that 30 million individuals are exposed to injurious levels of noise each day, contributing significantly to the overall cost of hearing loss in the nation of $56B per year. In addition to loud noise of various types, many pathological conditions affecting the inner ear, such as traumatic injury, toxins, aging, infection, and some genetic conditions may be associated with the excessive production of reactive oxygen species (ROS) leading to oxidative stress." (PR Newswire, 2003)

Consider that we as a nation in the twenty-first century will need to administratively handle and pay for hearing loss cases and concerns from the 1940's. Currently, the Veterans Administration process which includes both the administrative and hospital systems are still having to contend with hearing loss suffered by soldiers that served in World War II. The United States national debt crisis is all but staggering -- any burden such as hearing loss disability pay for soldiers who have served in the Korean War, Vietnam War, Dessert Storm and the various other conflicts could overwhelm the Veterans Administrative budget unnecessarily considering that the system has to also contribute to each soldiers hearing loss problems individually.

Unfortunately, the United States Army has not been overly proactive when it has come to dealing with the inherent problems associated with the loss of its soldiers hearing. Many veterans of all of the branches of service have publicly denounced the support and efforts of the armed forces in assisting them once hearing loss occurred. The Veterans Administration hospital and medical assistance programs have been dubbed equally ineffective. There are few to no proactive programs that are geared in the Army to proactively reduce or completely prevent hearing loss due from the many causes, especially toxic noise exposure. Education programs are not well thought out and simply ordering each soldier to wear protective hearing devices has not proven effective over the course of the long run.

Like the civilian problem of having employers only conform to a standard and therefore not making the concerted efforts needed to prevent hearing loss, the United States Army is in a position where they could reevaluate the entire toxic noise and other causes of hearing loss and establish viable preventative methods.

Hearing loss

Most people have an idea of what hearing is but relatively few individuals know exactly what hearing loss is or the causes associated to it. Hearing loss or hearing impairment can occur when there are one or more problems with the parts of an ear or ears. Hearing loss is very case specific because one person who has hearing loss or impairment may be able to hear certain sounds or be completely deaf.

Impairment entails something is not working as well as it should but there may still be some basic functioning. Hearing loss can go by many terms such as deaf, deafness, or hard of hearing. All could be one and the same situation but as pointed out, each individual is suffering from their own individual illness or situation and may or may not be comparable to any other hearing loss situation.

Although this report focuses on hearing loss as it is associated to military service, it is important to note that in the United States; approximately three of every thousand newborns are born with some type of hearing impairment thus making it one of the more common birth defects in our nation. This entails that there are many public and private organizations and foundations diligently working towards a cure. Until there is a solution however, the problem will continue to affect millions of individuals at birth. but, as we are now well aware, hearing problems can and do develop later in life and terms of service in the armed forces has a high incidence of hearing loss and tinnitus associated to it.

To understand how the ability to hear can be lost, it is important to first understand how hearing works. Although this is a simplified view, it is generally enough to clarify the situation. The human ear consists of three different subdivisions:

the outer ear the middle ear the inner ear

When functioning properly, these three unique parts work together and therefore a person has the ability to hear and process sounds. The visible outer ear or pinna functions as a cone that receives and slightly filters sound waves.

These sound waves travel through the outer ear canal and bounce off of or hit the eardrum in the middle ear. The middle ear's eardrum begins to vibrate and these vibrations move three very small bones within the middle ear. These bones are called the malleus or hammer, the incus or anvil and the stapes or stirrup.

The malleus, incus and stapes function is to help direct the sound waves in a certain direction into the inner ear. The vibrations that were triggered by the sound waves in the middle ear then travel to the cochlea which is filled with liquid and lined with cells that have thousands of tiny hairs on their surface.

The vibrations move the hairs and allow the hairs to change the original sound vibrations into nerve signals which are then forwarded to the brain for interpretation. This process is an extremely well meshed orchestra of events that gives is one's ability to hear.

It is also important to understand the various types of hearing loss and there are relatively few different types of hearing loss:

conductive sensory mixed (conductive and sensory combined) neural

Conductive hearing loss occurs if and when there are associated problems with any part of the outer or middle ear. Individuals with conductive hearing loss find that it is often only a mild hearing loss and it can be more than likely temporary if one receives medical treatment. Sensory hearing loss occurs when the cochlea is not functioning as it should. This type of damage could happen if the hair cells are damaged or destroyed or if the liquid that should be within the cochlea is leaked in some way.

Depending on the type of loss, the range of hearing loss could range anywhere between a person hearing only muffled sounds to not that individual not being able to hear any sounds. Sensory hearing impairments are in most cases permanent and may even affect a person's ability to speak normally and have linked to loss of overall balance.

Neural hearing loss is an internal issue with the connections between the cochlea and the brain and therefore implies that there is some sort of associated nerve damage or maybe even that the path of entry to the brain may be blocked or damaged in some way or manner.

Causes of hearing loss can very: besides birth defects, some specific causes of hearing loss can be attributed to:

middle ear fluid serious infections, such as meningitis head injury listening to very loud music, especially through headphones repeated exposure to loud sounds, such as machinery or explosions

If the inner ear's own antioxidant defenses are overwhelmed injury or even death and permanent loss of the sensory cells of the inner ear occurs. This leads to permanent hearing loss and often also tinnitus, or the sensation of ringing in the ear. The technology licensed by ABG from the Navy boosts the inner ear antioxidant defenses to prevent or treat the damage caused by the toxic ROS. Preventing and treating acute injury to the cochlea or hearing organ in the inner ear may also reduce tinnitus in the acute setting." (PR Newswire, 2003)

Historical Situation

In a recent news release meant to raise public awareness regarding several clinical hearing-aid trials which were the first of their kind because they were designed to aid hearing loss victims through mechanical correction in both quiet and noisy situations, another piece of surprising information was released.

The interesting information was not that the hearing aids could probably help millions of Americans deal with sensorineural hearing loss or other forms of nerve-related hearing losses -- the interesting data was how many military veterans were affected by hearing loss. "Department of Veterans Affairs (VA) and the National Institute on Deafness and Other Communication Disorders (NIDCD) conducted this rigorous scientific testing among 360 men and women aged 29-91 years with bilateral sensorineural hearing loss. About 70% were military veterans, and about half never used a hearing aid." (Beasley, 2004)

The United States military is currently investigating the situation. "A congressionally mandated study by the Institute of Medicine will assess noise-induced hearing loss and tinnitus associated with military service from World War II to the present, the effects of noise on hearing, and the availability of audiometric testing data for active duty personnel." (IOM Board: Medical Follow-Up Agency, 2004)

The armed forces have implemented an expert committee tasked with discovering the magnitude of the hearing loss problem as well as being charged with providing viable recommendations and solutions for the Department of Veterans Affairs. In the face of such pressures, safety and health experts are paying more attention to metrics in general, and hearing conservation is no exception. The military can no longer overlook the affects of noise-induced hearing loss and tinnitus associated with service in the Armed Forces.

The committee will attempt to review the plethora of staff-generated data about compliance and existing regulations for audiometric testing throughout the services during various periods of time since World War II. There should be a great deal of information for the committee to review and assess on hearing loss and that should lead to long overdue suggestions to help identify the many military sources that create damaging toxic noise during active duty.

The committee has the objective of identifying what the actual levels of noise exposure is needed to cause hearing loss or tinnitus as well as determining if those levels of noise exposure can somehow be delayed or mitigated. "Staff of the Medical Follow-up Agency will identify populations of veterans from each of the armed services (Army, Navy, Air Force, Marine Corps, and Coast Guard) and from each of the time periods from World War II to the present. The service medical records of a sample of these individuals will be obtained and reviewed for records of audiometric surveillance (including reference and termination audiograms)." (IOM Board: Medical Follow-Up Agency, 2004)

From that information, the committee can supposedly make the necessary suggestions of viable alternatives and solutions for the obvious risk factors associated to noise-induced hearing loss and thereby establish and implement new criteria for hearing conservation measures adequate for protecting service members in the same light as the Occupational Safety and Health Administration would do in the civilian business environment.

To demonstrate how crucial this committee's findings could be, during a recent congressional inquiry one returning veteran from Iraq pointed out the historical support soldiers and reservists suffering with hearing loss received by both the active military and the Veterans Administration. "My MEB process spanned over a nine-month period. On my physical exam my complaints of depression, tremors, vertigo, severe headaches, ringing in my ears, numbness to both arms and hearing loss were blatantly ignored and, in my opinion, purposefully, left off the Medical Evaluation Board Findings (DA 3947) which has prolonged my MEB process, which prolongs the time that I can seek competent medical and psychiatric care from the civilian world, and be close to my caring family My depression had become so severe I went to sick call and was told to return the next day." (Mosley, 2004)

Current situation

Modern life as well as military life has become noisier. "There was a time when hands cupped over the ears could adequately protect against the din, such as it was, of the industrialized world. This is no longer the case, as high-tech speakers, jet engines, leaf blowers, and machinery of all types spill their sounds invasively into our lives. (Tabachnick, 1994)

The twenty-first century is very noisy and the need for serviceman and women to keep up with hearing protection technology has become more crucial then ever. Soldiers throughout history have paid a heavy price for choosing to consciously ignore the subject of haring protection even though they may have been fully aware of the fact that excessive exposure to loud noises permanently damages one's hearing and can also be an early warning indicator of the later onset of tinnitus which is the well documented chronic ringing in the ears or head.

The United States Army currently provides ear plugs for basic trainees for the more obvious noise hazards such as the rifle, grenade or mortar ranges. "Powerful sound waves, heard or unheard, enter the delicate ear if it is left unprotected. The correct use of hearing protection devices can help protect one's hearing." (Tabachnick, 1994) if soldiers wear the hearing protection properly, they will receive more protection than if they wear the protection improperly. but, it is the case that far too often soldiers are never made aware of the need for them to utilize hearing protection in motor pools, helicopters and other military transports such as un-pressurized cargo planes and ATV's.

The other real problem is that in battle field scenarios, hearing protection may be ill-advised and may even be the cause of some fatalities. With that said, there are obvious draw backs to utilizing hearing protection devices in some scenarios. "In noisy environments with sound levels less than or equal to 85 decibels (dB), both muffs and plugs diminish speech discrimination." (Tabachnick, 1994) Ear muffs interfere with one's ability to find the origins of sounds which on a battlefield could be hazardous to one's health. "Additionally, it is well documented that hearing protection devices (e.g., earmuffs and earplugs) designed to protect soldiers or employees from noise hazards and the possibility of noise-induced hearing loss result in significant localization difficulties." (Vause & Grantham, 1999)

In other words, in a battle field environment, because hearing can be severely diminished when wearing hearing protection, a person would be forced to rely on alternative methods in those critical situations which may or may not be practical. "Military helmets are designed to protect soldiers from possible head injury during training and combat operations. Unfortunately, this protective headgear may also hinder the ability of a soldier to localize sounds." (Vause & Grantham, 1999) Basically, in a battlefield scenario, hearing protection devices may not be the best solution because of their inconvenient side affects.

Off duty

Battle field scenarios aside, the United States Army must also be concerned with their soldier's off duty activities. "... today, a growing source of hearing impairment is the tools and toys of recreation. Americans are pounding their ears with gas-powered leaf blowers and high-amplified stereos, with NASCAR races and 1,875-watt hair dryers, even, remarkably, with children's playthings." (Couzin & Terrell, 1999)

Only dedicated educational programs that are specifically designed to drive home the potential problems associated with hearing loss both on and off duty that is a universal program for the entire Army population will suffice in solving these non-battlefield problems that still inadvertently jeopardize each soldier's health and career as well as their team members who depend on them in crucial situations.

As is often the case, the pressures of active duty may lead to a need for extreme relaxation when off duty. The younger generation has adopted the walkman CD player which is capable of producing very loud music through technologically advanced headphones that drowned out external noise; there are powerful music boom boxes and concerts and even individuals who participate in their own musical bands. When the off duty soldiers attend NASCAR events or the plethora of other scenarios and situations that could easily cause irreversible hearing loss, the armed forces and the nation as a whole suffer.

Illness related

Hearing loss in regard to non-toxic noise is also of concern for the United States military. Armed forces are often deployed in less than sanitary conditions as well as the fact that they are subjected to insect derived disease. A typical example of disease born illness which could inadvertently lead to hearing loss is Aseptic or Sterile meningitis. Aseptic meningitis is an illness that can be characterized by the side effects of headaches, fevers, and an inflammation of the meninges which is the lining of the brain not caused by bacteria, as well as hearing loss being a very common side affect. "With aseptic meningitis, a person has signs and symptoms of meningitis but bacteria do not grow in culture. Many different things can cause aseptic meningitis, including viruses, fungi, tuberculosis, some medications, and infections near the brain or spinal cord, such as epidural abscesses." (Levy, 2004)

What should be of particular concern for the United States Army therefore are the various manners that diseases such as sterile meningitis that may lead to hearing loss can be transmitted. For example, by getting the West Nile virus, soldiers have a very good incidence of also contracting aseptic meningitis as the West Nile has begun to spread across the United States. Even thought the West Nile virus causes a self-limited meningitis, there are the incidence of the virus causing more severe illness such as hearing loss, encephalitis or paralysis similar to that seen in polio. The incidence of Soldiers being exposed to virus carrying mosquitoes actually is greater than the relative minority who are exposed to battlefield situations.

Military personnel can be exposed inadvertently to the causes of these types of bacteria, diseases and viruses while on the battlefield, during humanitarian deployments or simply while at home during an off duty weekend. "Enteroviruses are spread by hand-to-mouth contact, coughing, and to a lesser extent by contact with fecal matter www.ehendrick.com/healthy/002290.htm." Mumps is spread by coughing or contact with secretions from the mouth and airway, with increased incidence in the spring. Herpesvirus, both type 1 herpes simplex or herpes labialis) and type 2 genital herpes) can cause meningitis in children and especially infants. Chicken pox can also cause aseptic meningitis.

Rabies virus causes both an inflammation of the brain and meninges or a meningoencephalitis. HIV can cause aseptic meningitis, especially soon after exposure (acute HIV syndrome). Some fungi and mycobacteria can cause aseptic meningitis, although this is much less common. Certain medications can also cause aseptic meningitis, including antibiotics and some over-the-counter anti-inflammatory medications." (Levy, 2004)

Risk factors related to aseptic meningitis for United States soldiers usually includes external exposure to a person already infected by the associated viruses. This problem is particularly hazardous in humanitarian settings and exposure in undeveloped nation's battlefield settings to children and healthcare workers and individuals with suppressed immune systems. The solution to prevent hearing loss in these situations can be as simple as sanitary practices as well as up-to-date immunizations.

These methods can retard a majority of the exposures Army personal would have. Educational programs should be incorporated so that soldiers understand that exposure to those carrying or having been recently infected with potentially harmful viruses coupled unsanitary practices can lead to problems. The military is responsible for promoting standard hand washing practices, immunization (against mumps, for example), and other general good health measures that reduce the risk of developing infections that could lead to meningitis or the associated loss of hearing and nerve damage.

Noise related

The Armed Forces must educate the soldier about the hazards of toxic noise. The fact that a noise reduction rating for the standard Hearing Protection Devices range from 12dB -- 33dB, which entails that a soldier exposed to external noise with hearing protection greatly reduces that external noise by many decibels. Soldiers must also be educated in regard to the a hearing protection devices real world performance rating which usually takes into account a products aging, fitting, and other unpredictable human factors. "It's important to be aware that seemingly minor differences in decibels are not minor at all. Ten times more sound energy enters the ear in an 85dB environment than in a 75dB environment. Therefore, 20dB of real protection is ten times greater than 10dB. (Tabachnick, 1994)

The army has many types of hearing protection devices already available that come in a wide variety of shapes, costs, and degrees of efficiency to meet the majority of needs from battle fields to air cargo transports. "Contrary to popular belief, the noise reduction ratings for muffs are usually less than those of foam plugs, from 23dB -- 29dB. Muffs shouldn't be worn over eyeglasses or if the wearer has very thick hair (noise reduction is significantly degraded if the earmuff cushion next to the head is lifted away)." (Tabachnick, 1994) the key is to enforce, educate and utilize the proper equipment for the proper situation. As is too often the case however, soldiers and their leadership only take into consideration the comfort level in temporary situations when deploying the necessary hearing protection devise.

Standard ear plugs and ear muffs come in a wide variety and vary significantly in durability, effectiveness, and cost. The most ideal for battle field scenarios for ground troops seems to be the formable plugs. "Formable ear plugs are inexpensive, well tolerated, and are the most effective Hearing Protection Devices available today, with noise reduction rating ranging from 21dB -- 33dB. Plugs can be purchased in drug stores, hardware stores, safety supply outlets, and gun shops, and range in price from 35[cts.] -- $1 per pair. Foam plugs can be worn, removed, washed, and reinserted for as long as they continue to re-expand. Silicone and wax plugs are intended to be discarded after only a few uses. Because ear canal irritation can be caused by repeated use in a short period of time, plugs are best for long-term wear." (Tabachnick, 1994)

Current standard issue for new recruits are most likely premolded plugs. "These are made from a flexible but more rigid material than foam plugs. They need no rolling and can be inserted into the ear quickly. They retain their shape, come in different sizes (some people need different sizes for each ear), provide noise protection nearly equivalent to foam plugs, and can have a life expectancy of months if they're regularly cleaned and checked for wear. Premolded plugs, however, are less comfortable than foam plugs and require a slow twisting action to break the seal carefully when being removed." (Tabachnick, 1994)

Tankers and other mobile troops utilize muffs to lower noise levels. Muffs are significantly more comfortable than plugs and reduce the need to insert anything into the ear. They also have the added benefit of being able to be worn over plugs to double the decibel reducing protection and are designed with a flexible headband. Muffs have a long shelf life and often last several years as long as regular maintenance is performed to stop weather related cracking and cushions are replaced.

For special scenarios, there are custom designed plugs that meet specific noise toxicity scenarios. Custom plugs are usually manufactured of a soft vinyl, plastic, or resin material. They are usually more rigid than the before mentioned foam plugs. There are gradual alterations constantly needed because the ear canal is subject to change shape so new custom plugs are needed often. In regard to individual use, this custom approach works well but would be far too costly for an entire force distribution.

As mentioned, the best use of hearing protection devices may be the combination method. "The greatest possible noise reduction available today results from combining muffs and plugs, according to Elliott Berger, acoustical engineering manager for Cabot Safety Corporation. The noise reduction rating of these products are not additive, though. That is, a 30dB plug plus a 25dB muff won't equal 55dB of protection." (Tabachnick, 1994)

It is important to understand that the air-conductive pathway through the ear canal can be entirely blocked and the cranial bones will still produce enough sound into the ear to hear. "This natural bone-conductive property of the head limits sound attenuation to a maximum total of about 45dB -- 50dB. Bone conduction is responsible for the perceived amplification of one's voice -- called the "occlusion" or "ear plug" effect -- heard when wearing plugs or muffs. Elliott Berger suggests wearing ear plugs more deeply inserted or ear muffs with a larger volume cup to help minimize the amplification." (Tabachnick, 1994)

New technology

The tried and true methods of using plugs and muffs has not been as effective as may be needed to meet the needs of reducing and even preventing hearing loss. Technology may be the future solution the military and civilian businesses may need to meet these needs. In June of 2002 a new medical breakthrough was announced that may be the desired alternative. "Technology developed by the Naval Medical Center in San Diego could one day lead to a pill that would not only prevent Hearing loss, but even restore Hearing, 10 News reported. The hope is not only to protect the military, but others -- like airport crews -- whose jobs require that they work with a high level of noise."(NewScientist.com news service, 2002) the Navy is just as conscious of noise toxicity because of flight decks on aircraft carrier and Marines in simulated and real air and ground combat. The common denominator for hearing loss prevention is noise.

But researchers at the Naval Medical Center believe they have a solution. "Mechanical Hearing protectors, like ear plugs, have limitations. This technology -- in the form of a pill -- prevents or can reverse acute Hearing loss," said Col. Richard Kope, a doctor. According the medical center's research, when the inner ear is exposed to excess noise it produces toxins which can impair Hearing." (NewScientist.com news service, 2002)

The premise behind this new technology is that by reducing toxins in the ear they in turn prevent hearing loss. The technology is only in its infancy, but the preliminary research has shown that once hearing loss from excessive noise occurs, the pill has demonstrated an ability to restore the hearing capabilities. "The Naval Medical Center turned over the research in return for royalties when the Hearing pill comes to market, perhaps as early as 2007. So far, there is no name for the prescription pill, which the Navy hopes will trim the $1.5 billion it says it spends on hearing loss treatments each year." (NewScientist.com news service, 2002)

The idea is that the new pill would be being taken before a person would enter into a noise toxic area and have no chance of hearing loss. The active ingredient is a substance called NAC. NAC is the active ingredient in a formulation known as Mucamist. Mucamist an oral agent that is used to counteract the possible liver damage when a person overdoses on acetaminophen. "Potential clinical uses include hearing loss prevention in high-noise work and training environments and in environments where people are exposed to a combination of noise and toxins, such as military flight lines and certain industrial settings; protection against recreational noise hazards such as shooting; and treatment for acute acoustic injury as well as hearing loss due to genetic predisposition, chemotherapy treatment, and aging." (PR Newswire, 2003)

The concept works on antioxidants in the pill being able to prevent the noise from damaging the previously described inner ear hair cells. "In the reported study, NAC, given in a basic science model before and after simulated M-16 rifle fire consisting of 150 shots over 75 seconds, reduced permanent hearing loss by over 70%. A similar reduction in damage to the cochlear hair cells was also noted. In other related research presented by the Naval Medical Center group at ARO, data were reported indicating that two key mechanisms of inner ear injury were depletion of inner ear glutathione and damage to mitochondria. Glutathione is a key inner ear antioxidant and NAC replenishes the inner ear glutathione depleted by loud noise." (PR Newswire, 2003)