Hearing loss has a lot of different causes and manifestations. It can be sudden or gradual. It can occur in one ear or both ears. It can be temporary or permanent. It happens to people of all ages and is associated with the aging process. Before discussing causes and treatments for hearing loss, it is important to understand how hearing works.
How We Hear
There are three sections of the ear: the outer ear, middle ear and inner ear. Each section helps move sound through the process of hearing. When a sound occurs, the outer ear feeds it through the ear canal to the eardrum. The noise causes the eardrum to vibrate. This, in turn, causes three little bones inside the middle ear (malleus, incus, stapes) to move. That movement travels into the inner ear (cochlea), where it makes tiny little hairs move in a fluid. These hairs convert the movement to auditory signals, which are then transmitted to the brain to register the sound.
Types of Hearing Loss
Hearing loss is measured in four degrees: mild, moderate, severe or profound. The degree of hearing loss drives the selection of the best form of treatment on a case-by-case basis.
Sensorineural hearing loss (SNHL)
• The most common type of permanent hearing loss.
• Occurs when there is damage to the inner ear (cochlea), or to the nerve pathways between the inner ear and the brain.
• Often, SNHL cannot be medically or surgically corrected, but can usually be rehabilitated through hearing aids.
• Speech is usually distorted, quieter and incomplete.
Conductive hearing loss
• Occurs when the outer or middle ear structures fail to properly conduct sound waves to the inner ear.
• Conductive hearing loss is often medically or surgically treatable.
• Speech is still clear, but is much quieter since sound is being blocked.
Mixed hearing loss:
Mixed hearing loss refers to people who have both conductive and sensorineural hearing loss. Most people experience more than one type of hearing loss.
Central hearing loss:
This occurs when the central nervous system fails to send a readable signal to the brain, which is called a central auditory processing disorder. People with central hearing loss generally can hear all sounds, but can’t separate or process them.
Common Causes of Hearing Loss
Presbycusis – Age-Related
• Result of the aging process or extended exposure to environmental noise factors throughout a lifetime.
• Permanent change in inner ear.
Sociocusis – Noise-Induced
• Damage to hair cells and cochlea
• Occurs suddenly or gradually
• Approximately 16 million Americans between the ages of 20 and 69 have high-frequency hearing loss due to exposure to noise at work or in leisure activities. 1
Congenital – Genetic
• Results from a family history of hearing loss or predisposition.
Ototoxicity – Drug-Related
• There are 200+ known ototoxic (toxic to the ears) prescription and over-the-counter medications on the market today.2 This list includes:
o Certain antibiotics
o Some cancer treatments
o Some anesthetics
Common Signs of Hearing Loss
• Hear but not understand people
• Have difficulty understanding radio, television or public address systems
• Need to watch a person’s lips in order to understand
• Find yourself asking people to repeat what they have said
• Pretend to understand
• May avoid people and isolate yourself
• May find it emotionally and physically exhausting to communicate
• Think that you are the only one who has these difficulties
How Much Hearing Loss Warrants a Consultation?
Any noticeable change in hearing acuities:
• Should result in a hearing consult
• May represent a communication problem that interferes with one’s lifestyle
• May respond well to hearing aids and should be counseled about the benefits of amplification
• May be medically or surgically treatable
Hearing Loss Treatments:
The location, type and degree of hearing loss impact the choice of treatments for any hearing problem. The most common treatment options include:
• Antibiotics, decongestants and pain medication to overcome ear infections.
• Myringotomy, a piercing of the eardrum to allow for fluids to drain out of the outer ear.
• Insertion of a tube into the Eustachian tube (part of the anatomy that connects the middle ear to the back of the throat) to keep it open and allow for normal fluid drainage. This technique may be recommended for people who get frequent ear infections.
• Hearing aids.
• Surgery to remove benign or malignant tumors or correct bone- or nerve-related problems.
Hearing Loss Risk Factors:
Current smokers have a 70% higher risk, of having hearing loss than nonsmokers.3
the inner ear is extremely sensitive to blood flow. Studies have shown that a healthy cardiovascular system — a person’s heart, arteries and veins— has a positive effect on hearing. Conversely, inadequate blood flow and trauma to the blood vessels of the inner ear can contribute to hearing loss.4
there is a significant association between high blood pressure and hearing loss. Hypertension is an accelerating factor of degeneration in hearing ability due to aging. 5
hearing loss is about twice as common in people with diabetes compared to those without the disease. 6.
Adults with pre-diabetes, whose blood glucose is higher than normal but not at diabetes levels, have a 30 percent higher rate of hearing loss compared to those with normal blood sugar. 7
Effects of Untreated Hearing Loss
Many people put off getting help for their hearing loss because they think it’s insignificant – something they can deal with by simply turning the TV louder or asking friends to repeat themselves. But research has linked untreated hearing loss to significant issues such as:
• Adults with untreated hearing loss are more likely to develop problems thinking and remembering than adults with normal hearing.8
• Adults with hearing loss develop impairment in their cognitive abilities, earlier than their peers with normal hearing — an average of 3.2 years sooner.9
• People* with a hearing loss experience a 30-40% faster decline in cognitive abilities compared to peers without hearing loss.10
• Wearing hearing aids reduces the risk of cognitive decline associated with hearing loss.11
• Seniors with hearing loss are significantly more likely to develop dementia over time than those who retain their hearing.
• Adults with mild hearing loss are 2x more likely to develop dementia.
• Adults with moderate hearing
loss are 3x more likely to develop dementia.
• Adults with severe hearing loss are 5x more likely to develop dementia. 12
• Tinnitus is the #1 military-service disability 13
• Sensorineural hearing loss is by far the most common cause of tinnitus.14
• Tinnitus affects 45 million Americans.15
• Hearing loss results in social isolation. Adults with untreated hearing loss tend to withdraw from engaging with family and friends.16
• Adults with untreated hearing loss are more likely to report depression, anxiety, emotional instability and paranoia.17
• The degree of depression and other emotional or mental health issues also increases with the severity of hearing loss.18
• People with mild hearing loss (25 dB) are 3x more likely to have a history of falling. Every additional 10 decibels of hearing loss increases the chances of falling by 1.4 times the original risk.19
• Hearing loss negatively impacts the average household income up to $12,000 per year, depending on the severity of the loss.
• Hearing aids mitigate the impact of hearing loss on income by an average of 50 percent, which varies by severity of loss.20
• Adults who treat their hearing loss have higher employment rates than peers who don’t.21
• Though all human brains become smaller with age, shrinkage is accelerated in adults with hearing loss.
• Those with impaired hearing lose more than an additional cubic centimeter of gray matter each year.22
• Untreated hearing loss may result in serious long-term consequences to healthy brain functioning.23
1 National Institute on Deafness and Other Communication Disorders. (2014, March). Noise-Induced Hearing Loss.
Retrieved from: http://www.nidcd.nih.gov/health/hearing/pages/noise.aspx
2 Cone, B., Dorn, P., Konrad-Martin, D., Lister, J., Ortiz, C., & Schairer, K. (n.d.). Ototoxic Medications (Medication Effects).
Retrieved from: http://www.asha.org/public/hearing/Ototoxic-Medications/
3 Cruickshanks, K., Klien, R., Wiley, T., Nondahl, D. M., & Tweed T. S. (1998). Cigarette smoking and hearing loss: the epidemiology of hearing loss study. Retrieved from: http://www.ncbi.nlm.nih.gov/pubmed/9624024
4 Hull, R. H. & Kerschen, S. R. (2010). The Influence of Cardiovascular health on Peripheral and Central Auditory
Function in Adults: A Research Review. American Journal of Audiology, 19. 9-16. Doi:10.1044/1059-0889(2010/08-0040)
5 Agarwal, S., Mishra, A., Jagade, M., Kasbekar, V. & Nagle, S. K. (2013). Effects of Hypertension on Hearing. Indian J Otolaryngol Head Neck Surg. 2013 December; 65(Suppl 3): 614–618. Published online 2013 February 17. Retrieved from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3889339/
6 Diabetes and Hearing Loss (2013). Retrieved from: http://www.diabetes.org/living-with-diabetes/treatment-and-care/seniors/diabetes-and-hearing-loss.html
7 Hearing Loss Is Common in People with Diabetes (2008). Retrieved from: http://www.nih.gov/news/health/jun2008/niddk-16.htm
8 Lin, F. R., Yaffe, K., Xia, J., Xue, Q. L., Harris, T. B., Purchase-Helzner, E., … Simonsick, E. M. (2013). Hearing Loss and Cognitive Decline in Older Adults. For the Health ABC Study Group. Hearing Loss and Cognitive Decline in Older Adults JAMA Intern Med. 2013;173(4):293-299. doi:10.1001/jamainternmed.2013.1868
9 Lin, F. R., Yaffe, K., Xia, J., Xue, Q., Harris, T.B., Purchase-Helzner, E., … Simonsick, E.M. (2013). Hearing Loss and Cognitive Decline in Older Adults. JAMA Internal Medicine,173(4), 293-299. doi:10.1001/jamainternmed.2013.1868
10 Lin, F. R., Yaffe, K., Xia, J., Xue, Q., Harris, T.B., Purchase-Helzner, E., … Simonsick, E.M. (2013). Hearing Loss and Cognitive Decline in Older Adults. JAMA Internal Medicine,173(4), 293-299. doi:10.1001/jamainternmed.2013.1868
11 Amieva, H., Ouvrard, C., Giulioli, C., Meillon C., Rullier, L., & Dartigues, J. F. (2015). Self-reported hearing loss, hearing aids, and cognitive decline in elderly adults: A 25-year study. J Am Geriatr Soc. 2015 Oct;63 (10):2099-104. doi: 10.1111/ jgs.13649.
12 Lin, F. R., Metter, E. J., O’Brien, R. J., Resnick, S. M., Zonderman, A. B., & Ferrucci, L. (2011). Hearing loss and incident dementia. JAMA Neurology, 68(2), 214-220. doi:10.1001/archneurol.2010.362.
13 U.S. Department of Health & Human Services, National Institutes of Health, National Institute of Deafness and Other Communication Disorders (2015). Tinnitus. National Institute on Deafness and Other Communication Disorders. Retrieved from: http://www.nidcd.nih.gov/health/hearing/pages/tinnitus.aspx
14 American Tinnitus Association. (n. d.). Understanding the Facts. Retrieved from: https://www.ata.org/understanding- facts/causes
15 American Tinnitus Association. (n. d.). Understanding the Facts. Retrieved from: https://www.ata.org/understanding- facts
16 National Center for Health Statistics, Inter-university Consortium for Political and Social Research (1989). National Health Interview Survey. United States Department of Health and Human Services. Doi:http://doi.org/10.3886/ ICPSR09583.v1
17 Reinemer, M., & Hood, J. (1999). Untreated Hearing Loss Linked to Depression, Social Isolation in Seniors. Audiology Today, 11(4). Retrieved from: http://www.audiology.org/publications-resources/document-library/untreated-hearing- loss-linked-depression-social-isolation
18 Reinemer, M. & Hood, J. (1999). Untreated Hearing Loss Linked to Depression, Social Isolation in Seniors. Audiology Today, 11(4). Retrieved from: http://www.audiology.org/publications-resources/document-library/untreated-hearing- loss-linked-depression-social-isolation
19 Johns Hopkins Medicine. (2012). Hearing Loss Linked to Three-Fold Risk of Falling. Retrieved from: http://www. hopkinsmedicine.org/news/media/releases/hearing_loss_linked_to_three_fold_risk_of_falling
20 Kochkin, S. (2007). The Impact of Untreated Hearing Loss on Household Income. Retrieved from: http://www. betterhearing.org/sites/default/files/hearingpedia-resources/The%20Impact%20of%20Untreated%20Hearing%20
21 Kochkin, S. (2010). The efficacy of hearing aids in achieving compensation equity in the workplace. Retrieved from:http://old.betterhearing.org/pdfs/hearing_aids_and_employment.pdf
22 Johns Hopkins Medicine. (2014). Hearing Loss Linked to Accelerated Brain Tissue Loss [News Release]. Retrieved from: http://www.hopkinsmedicine.org/news/media/releases/hearing_loss_linked_to_accelerated_brain_tissue_loss_
23 Johns Hopkins Medicine (2013). Hearing Loss Accelerates Brain Function Decline in Older Adults [News Release]. Retrieved from: http://www.hopkinsmedicine.org/news/media/releases/hearing_loss_accelerates_brain_function_