Incidence of Hearing Loss – Cause, Risk Factor and Treatment

It is important to listen up and not take your hearing for granted. Hearing loss remains the 3rd most prevalent health problem in the United States. About 48 million Americans have lost some of their hearing, as per the research. So, how does hearing loss lead to an impact on the quality of your life and relationships?

Certain conditions like genetics, age and illness are the key factors playing a role in hearing loss. Modern life has added many more factors to the list. Prime among them is the ensuing noise pollution and loud noises which are a common part of urban life. Even certain medications are associated with hearing loss. With so many different untreated causes, how do you protect yourself from this problem? In many ways, prevention remains easier than cure. So, let’s start with the causes that can impact your hearing:

Causes of Hearing Loss

#1 Advanced Age

Advanced age is the most common hearing loss cause. In fact, 1 in 3 individuals aged 65 to 74 has some degree of hearing loss. Post the age of 75, the hearing loss goes up in 1 out of every 2 people. Researchers don’t completely comprehend why hearing falls with age. It could be the result of lifelong experience with noise as well as other factors damaging the delicate mechanisms of the ear.

#2 Noise-Induced Hearing

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Noise also wears down the hearing when it is continuous and loud. The Center for Disease Control/CDC reports that close to 22 million US workers are exposed to lethal noise levels while working.

This includes carpenters, soldiers, miners, construction workers, farmers, and factory workers. Even musicians suffer from noise-induced hearing problems. Special earplugs could be worn to protect the ears while performing.

Noise-induced hearing loss results from chronic exposure to loud, excessive noise, resulting in a temporary increase in thresholds or shifts.

The threshold is the quietest, lowest sound heard and may or may not impact permanent hearing, based on the length of exposure and the level of noise. Acoustic trauma can also result from explosive, impulse noise blasting at massive intensity levels of more than 180 dB sound pressure levels. This can cause hemorrhages and eardrum perforation or cochlear impact.

Military services also cause noise exposure. Most study of noise-induced hearing, however, is in the case of occupational cohorts. Deployment to combat zones, proximity to IED and combat based head injuries are associated with early onset hearing loss. Occupational exposure to the noise is regulated by the Occupational Safety & Health Administration. Further, NIOSH has recommended occupational exposure limits of 85 dB SPL for a weighted average time of 8 hours. It is recommended that the use of hearing protection measures at extended sound levels be used as a precautionary measure. Along with ear muffs, other hearing protection such as earplugs offers protection in workplaces with higher noise levels. Administrative controls can also be used to reduce exposure, as per OSHA in 2016.

NIOSH estimated that anywhere from 5 to 30 million workers in the United States are exposed to occupational noise, placing them at the likelihood of developing hearing loss, with close to nine million at risk due to exposure to chemicals like solvents which are ototoxic. Further, a 30-year review of hearing loss data discovered that hearing loss risk may be on the decline. The link between age-related hearing loss incidence and noise exposure is tough to determine, as most age-associated hearing losses impact hearing capabilities at higher frequencies.

Numerous studies have found noise exposure history was not associated with the rate of later hearing acuity declines or hearing loss incidence, even in analyses limited to those presently employed. In recreational, non-occupational and home settings, the noise levels and exposure lengths vary widely. Distance from the source of sound is a factor, as is the length of continuous exposure and volume of the sound. Hunting and target shooting are linked to acute-onset hearing loss.

Other activities associated with high and sustained noise levels increase hearing loss risk including listening to sounds and music at higher volumes, such as earbuds and headphones that serve to increase sound proximity. This also includes being part of a music band, attending loud musical concerns and using high-noise tools like lawnmowers and leaf blowers. Ongoing and present research efforts by institutes and government departments have examined noise-induced hearing loss and its treatment and etiology.

Reducing time spent in noisy environments and wearing hearing protection to reduce noise exposure in the ear, preventing noise-induced hearing loss. Background noise can be alleviated. The most common form of acquired hearing losses and previously reviewed research is age-linked hearing loss. Numerous cardiovascular risk factors, lifestyle factors, neurotoxins and other factors linked to hearing problems. There have also been studies measuring longitudinal differences in hearing thresholds.

#3 Medicine Intake

Specific medicines also impair hearing and balance. Close to 2 hundred drugs and chemicals trigger side effects in hearing and problems in balance. This includes certain antibiotics, chemo drugs, loop diuretics, and aspirin as well as malaria drugs. Medicines for sexual disorders can also cause this problem. Sudden hearing loss can happen over a couple of hours or days. This means rapid loss of 30 dB or more of hearing capabilities. A normal conversation is around 60 dB. Sudden hearing problems generally impact only a single ear.

There are now 3 new cases per 10K individuals each year. Doctors are not able to discover the causes in most cases. However, many medicines have ototoxic effects and the most well known of these are chemotherapy agents and specific antibiotics. Some reports from research conducted longitudinally have found links between medicine usage and hearing loss risk.

No associations were found between the use of nonsteroidal anti-inflammatory medication or medicines that lower lipids like statins specifically for hearing loss over 15 years. However, some studies reported hearing loss associated with aspirin, NSAIDs, and acetaminophen. While it is difficult to study the impact of medication while accounting for reasons individuals use them for polypharmacy and prescription bias. Further, studies are vital to understanding the impact of medication use on auditory function changes.

#4 Illness and Trauma

Illnesses such as heart diseases, diabetes, high BP also endanger the ears by lessening the blood flow to these organs. Bone diseases of the middle ear and inner ear, such as Otosclerosis and Meniere’s disease impact the hearing as well. Trauma caused by ruptured eardrums or skull fractures also put the ears at serious risk for hearing issues. Infection or earwax can also lessen hearing and block the ear canals.

The complexity of physiologic or neural mechanisms that underlie hearing and communication in combination with environmental and genetic factors can be associated with or the reason for hearing loss makes it challenging for research and one that remains to be learned. The major causes and risk factors for hearing loss include congenital and acquired, though there is a complex overlap between the two, including potential susceptibilities to certain risks.

#5 Congenital and Hearing Loss

Estimated 2 to 3 of every 1000 newborn babies in the US suffer from hearing issues; of this, an estimated 50 to 60 percent are associated with genetic causes. More than a hundred genes have been identified as impacting hearing capabilities like non-syndromic genes. There are also more than 400 genetic syndromes resulting in other clinical pathologies that impact hearing. In fact, newborn hearing is screened and in 2013 alone, CDC estimates more than 97 percent of newborns in the US were screened for hearing loss.

The degree and type of hearing loss appearing in newborns varies. Autosomal recessive loss of hearing results from mutations of the gene GJB2 estimated at 20 percent of all congenital hearing loss. Variations in the severity of hearing loss are there, but severe hearing loss that occurs early in life is usually prelingual.

Research has found three genes associated with autosomal hearing loss are WFS1, COCH, and MYO7A. WFS1 mutations affect hearing at higher frequencies, Hearing remains normal in lower frequencies. For those facing mutations in the MYO7A gene, hearing loss is progressive and gradual, manifesting in the first ten years of life. For those facing mutations in the COCH gen-three, hearing loss commences in the 20s and while progression is variable, complete deafness takes place 20-30 years after this.

#6 Acquired Hearing Loss

Acquired hearing loss is sudden, gradual in onset and is caused by a variety of health conditions, exposures or diseases, including mumps, measles, meningitis, and otosclerosis. Otosclerosis or the progressive fusion and melding of ossicles of the middle ear, chronic ear infections, inflammatory or autoimmune disorders, infection or fluid in the ear or otitis media are some other conditions impacting hearing. Also, perforation or thick tympanic membranes or rupture of this eardrum and the use of antibiotics, chemotherapeutic or antimalarial medicines. Head injuries or other trauma and exposure to long-term noise are also reasons for hearing loss. Cerumen or earwax or even foreign obstructions in the ear canal and aging or presbycusis are also causes of acquired hearing loss.

#7 Lifestyle and Social Factors

Indicators of high SES status such as levels of education or professional occupational categories are linked to lower chances of hearing loss or rate of decline in many studies. Generational differences in educational attainment have explained birth cohort effects on the prevalence of hearing loss; the impact of the birth year was attenuated in the research.

No cohort studies have reported an association between alcohol intake and hearing loss. However, current smokers have a 31 percent raised risk of developing hearing loss in 15 years of follow up. The risk of hearing the loss in those who stopped smoking is the same as those who never smoked. Cigarette smoking is not linked with 5 or 10-year risks of developing hearing loss in this cohort, indicating efforts accrue gradually.

#8 Health Conditions

Population-based cohort studies found no link between hypertension and BP and the risk of hearing loss. Higher systolic BP was found associated with hearing the loss in healthier cohorts. Hypertension was also linked with a faster gall in hearing acuity. Further, obesity and central adiposity are also linked to hearing loss. Numerous longitudinal studies have found waist circumference or obesity, a marker of central adiposity, as well as insulin resistance and cardiovascular risks, are linked with increased chances of hearing losses. Larger waist circumference in younger individuals and obesity in older adults showed faster deterioration in hearing. One study even found 8% increased the risk of hearing loss for every additional waist circumference of 10 cms. BMI was associated with a higher 5-year risk of hearing loss. More research has found body mass index and larger waist circumference was linked with self-reported hearing deficits.

A lot of cross-sectional studies have reported a higher prevalence of hearing problems among individuals with diabetes. Highly elevated levels of glycosylated hemoglobin levels are linked with 2-fold increased chances of developing hearing loss during the fifteen years follow up. Cardiovascular disease risk factors and processes are involved in hearing loss linked to aging. One study even found that the intima-media thickness of the carotid artery is associated with hearing loss and linked to arteriosclerosis or thickening and blockage of the arteries. Developing hearing loss rose by 28 percent for 0.2mm increase in thickness of the intima-media. The plaque was also associated with an increased risk of hearing loss.

Higher levels of inflammation markers were associated with age-related disorders. The higher degree of high sensitive c-reactive protein was linked with a 2-fold increased risk of hearing loss over a ten year period among individuals under age 60. No association was found among individuals aged 60 or more at baseline. Cross-sectional cohort studies have shown links between genetic polymorphism linked with the tumor necrosis factor and tumor necrosis factor receptor or hearing thresholds but no link between inflammatory linked polymorphism and hearing loss. Chronic low-grade inflammation plays a vital role in age-related hearing loss.

How Hearing Loss Works

The hearing is the result of sound waves reaching structures inside the ear. Specifically, sound-wave vibrations are converted into nerve signals recognized by the brain as sound. Ears comprise three main areas — outer, middle and inner. Sound waves pass through the outer ear and cause eardrum vibrations. The eardrum and three small bones of the middle ear amplify vibrations as they travel to the inner ear. Vibrations pass through fluids in a snail-shaped structure in inner ears. Linked to the nerve cells in the cochlea are 1000s of tiny hairs that translate sound vibrations into electrical signals transmitted to the brain. Vibrations of different sounds impact tiny hairs in various ways, causing nerve cells to send different brain signals.

Aging and exposure to loud noises cause wear and tear on the hairs and nerve cells in the cochlea that send the brain sound signals. When the hairs or nerve cells are damaged or not there, electrical signals are not efficiently transmitted and hearing loss takes place. Higher pitched tones may also be muffled. Heredity makes one prone to these changes and this is known as sensorineural hearing deficits, which is permanent. Earwax blocks the ear canal and prevents soundwave conduction. This can be easily restored with the removal of earwax. Abnormal tumors and ear infections or ruptured tympanic membrane perforation ruptures and impacts hearing.

Risk Factors

Factors damaging or leading to loss of nerve cells and hairs in the inner ears include aging, heredity, occupational noises, recreational noises, medication, and illnesses.

Impact of Hearing Loss

Hearing deficits can impact the quality of life negatively, too. Among aged adults with hearing loss, common issues that occur include depression, anxiety, and misperceptions of emotions. Unfortunately, those with hearing loss do not seek treatment at all or delay before seeking treatment. This can cause serious problems. In a lot of cases, hearing fades so incrementally, that there is no clarity.

Hearing loss has been classified by degrees:

#1 Mild Loss

In this form of hearing loss, one-to-one conversations work fine, but it is hard to catch the words when there is background noise.

#2 Moderate Loss

In this form of the hearing deficit, asking people to repeat themselves in conversations on the phone or in person is common.

#3 Severe Loss

Following conversations is impossible without a hearing aid.

#4 Profound Hearing Loss

One cannot hear what other individuals are speaking unless one is extremely loud. The person suffering from this deficit cannot hear a word without a cochlear implant or a hearing aid. Early, high pitched sounds and ‘s’ and ‘f’ become harder to make out. There may soon be difficulty in following conversations when more than one individual speaks at once. Other people may appear to be mumbling and not speaking clearly. Often misunderstanding what others say and responding inappropriately or complaints with the TV volume, hearing, ringing or hissing sounds in the ears called tinnitus, are some of the signs of this type of hearing loss.

Treatment

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This depends on the source and type of hearing loss. Effective medical treatment for sudden hearing loss, for example, raises chances of recovery. Surgery can reverse the loss of hearing caused by infection, scar tissue or otosclerosis. Other diseases like Meniere’s associated with hearing loss require a different diet and medication. Hearing loss caused by infections can be cleared up with antibiotics.

In case hearing loss comes from the use of medicines, you need to check with your medical practitioner regarding the dosage. Most individuals with extensive and permanent hearing loss benefit from a hearing aid. These small hearing devices occur in or behind the ear to increase the loudness of the sound.

Other sound-enhancing technologies comprise personal listening systems for tuning in to what needs to be heard and muting other sounds. Listening systems on devices like television or radios make it easier to hear the sound without turning the volume up. Different types of phone amplification devices and captioned phones also let callers make conversation possible on mobile and home phones.

For young children or older adults with profound loss of hearing, cochlear implants are preferred.

When to See a Doctor

Signs and symptoms of hearing loss include muffling of sounds like speech, a problem understanding words especially when there is background noise or people talking and difficulty hearing consonants. You may also need to turn up the volume or ask individuals to speak slowly, loudly and clearly.

If you have sudden hearing loss, especially in a single ear, seek immediate medical care. You also need to talk to the doctor if problems in hearing are interfering with everyday life. The hearing is deteriorated if you show symptoms and signs of hearing loss.

Prevention

Preventing hearing loss involves taking on steps to prevent noise-induced hearing loss and avoiding age-related hearing loss.

#1 Protect Your Ears

In a noisy workplace, you need to protect your ears. Choose specially designed ear-muffs that protect the ears by bringing loud sounds to desired levels. Foam, custom-molded or pre-formed earplugs of plastic or rubber can also protect ears from noise and damage.

#2 Test Your Hearing

It is also important to have your hearing tested. Regular hearing tests are a must if one works in a noise-filled environment. Regular testing of hearing can prevent detection of hearing loss. Take steps to prevent further hearing loss.

#3 Avoid Risks in Recreation

Some activities like hunting, listening and riding a snowmobile for long periods can damage hearing. Hearing protectors or taking breaks from recreation that has a loud volume can protect your ears. Turning down the volume when listening to music can help in avoiding hearing damage.

Hearing Loss: Effect and Impact

Hearing loss can develop at any time during life. The onset can be gradual o sudden and one or both ears can be impacted. As hearing loss results from numerous causes like trauma, infection, excessive noise exposure or aging or even pathological manifestations in the auditory system. Hearing loss may be temporary or easy to treat if medical or surgical methods are used. Most hearing loss, however, is progressive or permanent. While evaluating the burden of hearing the loss in a population, it is essential to recognize heterogeneity in severity and nature of hearing loss. Individuals also differ in the extent to which auditory rehab, hearing aids and hearing assistive technologies improve communication functions.

Lowering the impact of hearing loss and improving function and health should be the focus.

Incidence and Extent of Hearing Loss

Studies have examined the prevalence and incidence linked to hearing loss. Some studies include the Blue Mountains Hearing Study and Epidemiology of Hearing Loss Study. Institute of Medicine reports have explored hearing loss in veterans and military personnel.

Along with estimates for risk of developing disorders, studies of incidence measure the risk associated with characteristics like race, gender and age, and potentially modifiable exposures and other factors adding further evidence for causal pathways.

Reported incidence rates, standardized to annual or yearly rates per 1000 persons vary from 12 per 1000 individuals in a year in Great Britain to 42.8 per 1000 persons per year in Wisconsin. The Blue Mountain Cohort Study and the Beaver Dam Cohort Study found rates to be 42.2 per 1000 individuals per year and 42.8 per 1000 individuals in a year.

Further, the risk of hearing loss was massive in older adults. The Framingham Heart Study, diabetes and cancer-related studies found the risk of hearing loss is two-fold higher in the event of cardiovascular diseases, five-fold higher than the risk of diabetes and ten-fold higher than cancer risks. The risk of bilateral hearing loss is 7x times higher than the risk of bilateral visual impairment.

Age and gender-specific 5-year incidence of hearing the loss in either ear for the study on Epidemiology of hearing loss and bilateral hearing loss in Blue Mountains Hearing study showed that hearing loss was higher at older ages, and higher among men than women. Further, the incidence is greater for men less than 70 years of age than for women of the same age. An epidemiological study of hearing loss found 18 percent of 60-69-year-old women and 35% of men in the same age range developed hearing loss in 5 years.

In around 15 more years, when participants fell in the age range of 75 to 84 years of age, 71 percent of women, as well as 84% of men, developed hearing loss. The risk of hearing loss doubled within 5 years of age and men were twice as likely than women to develop hearing loss.

Prevalence of Hearing Loss

Numerous cross-sectional research has further prescribed the prevalence of loss of hearing. Data from an NHANES study showed the prevalence of hearing loss rises steeply with the age, from 3 percent among 20 to 29-year-old adults to 49 percent among those aged 60 to 69 years. Bilateral hearing loss was found to be 45.6 percent among those aged between 70 and 74 and 80.6% in the age group which was 85+ or above.

It has been estimated using this data that 29 million adults aged 20 to 69 years in the US suffer from hearing loss. Around 30 million people aged 12 and older suffer from bilateral hearing loss and 48 million have poor hearing in a minimum of one ear. In another cohort study, conductive hearing losses were found in 8 percent of the respondents while 0.2 percent have a hereditary hearing loss called otosclerosis. Hearing loss can further be aggravated by conditions like disability and old age. Pregnancy can also hamper hearing in genetic cases. Most participants, according to research, suffer from bilateral symmetrical losses consistent with the predominant type among adults being sensorineural hearing loss acquired in adulthood.

Studies have examined hearing losses including mild, moderate, severe or profound losses. The severity of the hearing loss determines healthcare needs in important ways. Some studies have examined changes in hearing loss prevalence over time in the US. Evidence from examinations of temporal trends, birth cohort effects, and secular changes suggest hearing loss may be preventable since genetic changes are expected to slowly accrue. A strong birth cohort effect was found in data from the Epidemiology of Hearing Loss Study cohort and their offspring.

Many longitudinal studies have examined changes in hearing thresholds across time. Rates of change were faster at older ages.

Impact of Hearing Loss

The impact of hearing loss on individuals is dependent on the severity of the loss and the lifestyle, specific environment and communication needs. The same degree of hearing loss reports different hearing difficulties. Moreover, since humans vary in their reactions to challenges and abilities to find ways to adjust to changes in health, individual personality, resiliency, coping style and duration of hearing loss impacts how hearing abilities are perceived. So, a personalized approach to healthcare is a must. The burden of hearing losses may be hard to quantify and detect. Studies measuring the impact of hearing loss have often measured the only quality of life from the point of view of health. Other studies focus on differences in communication needs.

Quality of Living

In a population-based study, participants with hearing losses at the baseline visit had a lower quality of life, as opposed to those with normal hearing. Greater hearing loss severity was also linked with higher communication difficulties. Health-related quality of life was lower in older respondents.

Mental Health

A large study found no link between sensory impairments and mental health or depression levels in a follow-up. Hearing loss does not burden those individuals who attempt to communicate with someone who has hearing loss. Several studies have measured the impact on the mental health of spouses of those with hearing loss. In an Alameda County study, hearing difficulties with communicating were associated with weaker mental health and physical well being 5 years on. A link between hearing and cognitive function and dementia were long recognized as signals transmitted are processed and recognized by the human brain as words and sounds. Early reviews have also reported a link between dementia and hearing loss. The association may even go both ways, with one study finding impairment of cognitive faculties impacted hearing loss. In another study, hearing loss was associated with a six-year decline in the Visual Verbal Learning Test. Risk of dementia was also found 24 percent higher for 10 decibels of hearing loss after adjusting for factors like race, education, age, sex, hypertension, diabetes, and smoking.

The chances of cognitive impairment also rose 7 percent for every 10 decibels of hearing loss at the baseline. Baseline hearing loss was also associated with a decline in scores on digital symbol substitution and mental state examination tests. MRI studies further found whole brain atrophy and right temporal lobe atrophy rates were more among individuals with baseline hearing loss than normal hearing participants. Most respondents had mild hearing loss and baseline volumes were similar between those with and without hearing loss. The studies further found sensorineural hearing loss and cognitive functioning change as one grows older.

Functionality

Studies have also examined the complex link between the severity of loss measured via audiometry and everyday impact on function. Separating actual hearing acuity from other factors is important here. Older adults, for example, reported fewer disabilities due to hearing loss due to differences in coping styles across generations.

Other research has examined hearing loss and its impact on work and declines in physical functionalities. NHANES research found hearing loss was linked to increasing falls in the previous 12 months.

The Health ABC study further found participants with hearing loss were likely to have been hospitalized earlier. People in another study with moderate to severe hearing problems experienced a 2.7x times increase in needing help from others. People with severe hearing deficits may need more help.

Odds of reporting difficulties and delays in accessing healthcare were 1.85 times higher in groups. Adults with congenital hearing loss need treatment. While hearing healthcare aids and hearing aids may be provided in such individuals, coverage changes for insurance purposes as the transition to adult years is made. Long-term healthcare is needed to help this subset thrive as adults.

Conclusion

Thus, hearing loss or deficits in auditory capacities can dent the quality of life and even impact mental and physical health. The impact of auditory problems can be quite chronic, so care should be taken that those with hearing deficits are provided timely health care, hearing aids, and medical attention.