By Joan McKechnie
Hearing loss caused by the progression of age is known as age-related hearing loss or "presbycusis." Hearing loss with age is permanent and takes effect as the body matures at a gradual rate. It is reported that over 35 million Americans display the tell-tale symptoms of hearing loss, particularly people over the age of 65, according to a MarkeTrak VIII survey.
As the population continues to live longer due to ever more sophisticated healthcare solutions and breakthroughs in medicine, the numbers of Americans with hearing loss will increase to 40 million by 2025 and 53 million by 2050, according to the survey.
How hearing works
Like other sensory organs, the ear is a complex structure of bones, nerves and soft tissue. To hear sounds (vibrations in the ear), all of the ear's various parts must work in harmony. When one part no longer works, hearing is impaired. Sensory awareness – be it sound, sights, smell, touch or hearing – relies on capture triggers, which are translated by the brain, to work properly and give our senses context.
What we perceive as sound is actually vibrations in the air or sound waves. These sound waves are directed to the middle ear by the funneling effect of the outer ear (the pinna). This process pushes sound to the end of the ear canal causing the eardrum to vibrate and in turn passes these vibrations through three tiny bones of the ossicular chain in the middle ear.
These three bones (malleus, incus and stapes) form a bridge to transfer the energy of the sound waves from the outer section of the ear through to the fluid section of the inner ear, the cochlea. A critical part of this journey culminates in the inner ear where thousands of tiny "hair cells" fire signals via the hearing nerve fibers to the brain for interpretation.
As we mature and due to the detrimental effect of the free radicals in the human body, the quantity and quality of these pivotal hair cells is reduced, and our ability to pick up certain frequencies of sound is hampered. In the case of age related hearing loss, the process occurs over many years, thereby making it difficult to notice until a certain threshold is crossed and symptoms begin to impact quality of life. When and if a person will suffer from age-related hearing loss will depend on a number of factors, including:
- Exposure to harmful noise over years leading to loss of ‘hair cells' due to noise trauma (working in loud environments without hearing protection, exposure to loud music and other lifestyle choice we make)
- Family history of age-related hearing loss
- Smokers are more likely to suffer from hearing loss than non-smokers
The level of hearing loss will vary from person to person. The number of decibels required above the normal level to hear defines the severity of the loss. The categories below reflect the dBHL loss (decibels Hearing Level), which determines the severity of hearing loss:
- Mild hearing loss: Loss of 20-39 dBHL
- Moderate hearing loss: Loss of 40-69 dBHL
- Severe hearing loss: Loss of 70-90 dBHL
- Profound hearing loss: Loss of greater than 90 dBHL
Symptoms of hearing loss with age
Symptoms include difficulty in hearing the people within noisy environments. The background noise may seem far too loud compared to the actual speech. Other signs and symptoms of hearing loss with age include:
- Sounds seem less clear
- Not being able to hear the telephone or doorbell ring when others can
- Other people may sound mumbled or slurred
- Inability to hear high-pitched sounds such as "s" and "th"
- Frequently asking people to repeat themselves
- Having to have the television or radio turned up much higher than other family members
- Feeling tired after participating in a conversation held within background noise
Treatment options for hearing loss as we age
As with any other medical condition, the first step is to determine the cause of the hearing impairment by having hearing checked. Your family doctor can perform a basic check and refer you to an audiologist for further checks if he or she deems appropriate. It is important to distinguish the reason between age related, noise induced, infection led (e.g., mumps, measles, influenza, meningitis) and other less common reasons.
In the case of age-related hearing loss, treatment involves managing the hearing loss so that it affects day-by-day activities as little as possible. Because the hair cells cannot regrow, there is no cure. However, there are medical ways to minimize its effects. Your healthcare provider will be able to suggest various hearing devices from hearing aids to amplified alerting devices.
The future of age-related hearing loss
While in human beings the pivotal hair cells cannot regrow or regenerate, they do in birds. It leads scientists to suspect that using stem cell therapy, it will one day be possible for humans to regrow hair cells meaning that age-related hearing loss could be treated instead of managed.