Hearing impairment is also known as hearing loss. The hearing loss which is happening gradually as we age (presbycusis) is a common condition. In the United States of America about 25% of people between the ages of 55 and 64 have some degree of hearing loss [1]. For people who are older than 65, the number of people who have some hearing loss is almost one in two. Chronic exposure to loud noises and aging are significant factors which can lead to hearing loss. [2] There are other factors, such as excessive earwax which can temporarily prevent your ears from conducting sounds as well as they should. [3] The most types of hearing impairment cannot be reversed. But you do not have to live in a world of muted and less distinct sounds. Your doctor or the hearing specialist can help you to take steps to improve what you hear.
Signs and symptoms of hearing impairment
- Avoidance of some social settings
- Withdrawal from conversations
- Needing to turn up the volume of the television or radio
- Frequently asking others to speak more slowly, clearly and loudly
- Trouble hearing consonants
- There are some people who can have difficulties with understanding words, especially against background noise or in a crowd of people
- Muffing of speech and other sounds
Causes: Some causes of hearing loss are including damage to the inner ear, a buildup of earwax and a ruptured eardrum. [2,3] It is very important to understand how you hear because this can help you to understand how the hearing loss occurs.
Hearing impairment
How we hear: Hearing is happening when the sound waves reach the structures inside your ear where the sound wave vibrations are converted into nerve signals that our brain recognizes as sound. Our ear consists of 3 major areas: inner ear, middle ear and outer ear. Sound waves pass through the outer ear and cause vibrations at the eardrum. The eardrum and 3 small bones of the middle ear amplify the vibrations as they travel to the inner ear. There, the vibrations are passing through fluid in a snail – shaped structure in the cochlea (inner ear). It is attached to the nerve cells in the inner ear and there are thousands of tiny hairs that help translate sound vibrations into electrical signals that are transmitted to the brain. The vibrations of different sounds affect these tiny hairs in different ways which is causing the nerve cells to send different signals to our brain. This is the way how we distinguish one sound from another.
How hearing loss can occur: Here are the causes of hearing loss:
- Ruptured eardrum (tympanic membrane perforation): Infection, poking your eardrum with an object, sudden changes in pressure and loud blasts of noises can cause your eardrum to rupture and affect your hearing. [4]
- Ear infection and abnormal bone growths or tumors: In your outer or the middle ear, any of these can lead to hearing loss. [5]
- A gradual buildup of earwax: Earwax can block the ear canal and it can prevent conduction of sound waves. This can be restored with earwax removal. [3]
- Damage to the inner ear: It is known fact that the aging and exposure to loud noise may cause wear and tear on the hairs or nerve cells in the inner ear that send sound signals to the brain. When these nerve cells or hairs are missing or damaged, electrical signals are not transmitted as efficiently and hearing loss happens. For some people it can become difficult for them to pick out words against the background noise. Heredity can make you more prone to these changes. This type of hearing loss is known as sensorineural hearing loss which is permanent. [4]
Risk factors: Here are the factors which can damage or lead to loss of the hairs and nerve cells in your inner ear:
- Some illnesses
- Some medications
- Recreational noises
- Occupational noises
- Heredity [6]
- Loud noise
- Age
Complications: Hearing loss can cause side effects in the quality of our lives. Anxiety, depression and an often false sense that others are angry with you are common reported complications from older adults. Many people live with the hearing loss before they seek for treatment of it. This can also cause lasting problems for people that love them, if you try to cope by denying your hearing loss or withdrawing from social interactions.
References:
[1] National Institutes on Deafness and Other Communication Disorders (NIDCD). Quick statistics about hearing. Retrieved from www.nidcd.nih.gov/health/statistics/quick-statistics-hearing
[2] Centers for Disease Control and Prevention. How does loud noise cause hearing loss? Retrieved from cdc.gov/nceh/hearing_loss/how_does_loud_noise_cause_hearing_loss
[3] Aleccia J. The dangers of excessive earwax. Scientific American. 2018. Retrieved from www.scientificamerican.com/article/the-dangers-of-excessive-earwax/
[4] Holmes D. Eardrum regeneration: membrane repair. Nature. 2017;546.
[5] Yiengprugsawan V, Hogan A, Strazdins L. Longitudinal analysis of ear infection and hearing impairment: findings from 6-year prospective cohorts of Australian children. BMC Pediatrics. 2013.
[6] Kochhar A, Hildebrand MS, Smith RJH. Clinical aspects of hereditary hearing loss. Genetics in Medicine. 2007;9:393–408.
