Presbycusis (age-related hearing loss)
One of the most common causes of hearing loss is presbycusis, or age-related hearing loss. Diminished hearing is a common side effect of aging, usually coming on gradually and affecting high-pitched sounds most frequently. It occurs as a result of natural changes in the inner ear of individuals over time due to a variety of reasons including:
- Constant, cumulative daily noise exposure
- Hereditary factors
- Changes in the blood supply to the ear caused by heart disease, high blood pressure, vascular conditions and circulatory problems
- Side effects of some medications
An estimated one-third of adults aged 65 or older experience age-related hearing loss; that number jumps to nearly 50 percent by the age of 75. Presbycusis usually affects both ears equally. It may be mild, moderate or severe.
Noise Exposure
Noise induced hearing loss is the most common type of hearing loss experienced by younger individuals. It can be caused by exposure to a single loud sound, such as a gunshot or explosion, or by continuous exposure to loud noise over a period of time. When sounds exceed 85 decibels (dB), they are considered hazardous to your hearing health. Continuous exposure to volume levels that high cause permanent damage to the hair cells in your ears. Activities that put people at risk for noise-induced hearing loss include:
- Hunting
- Riding a motorcycle
- Listening to music at high volumes
- Playing in a band
- Attending rock concerts
An estimated 15 percent of Americans aged 20 to 69 have hearing loss that may have been caused by noise exposure. This type of hearing loss can be prevented by wearing earplugs and protective devices.
Genetics
Some hearing losses are hereditary and caused by gene mutations. These mutations can cause hearing loss in several ways. Inner ear sensory hair cells play a vital role in our hearing and mutations in these cells can prevent them from functioning properly, resulting in hearing loss.
Genetic factors also make some people more susceptible to hearing loss than others. Their genes make them more predisposed to hearing loss due to aging or induced by noise, drugs or infections. It is estimated that the causes of age-related hearing loss are 35 to 55 percent genetic. Gene mutations may cause several non-hearing related, hereditary conditions combined with a deformation of the inner ear, resulting in deafness at birth or later in life. Examples of hereditary hearing loss causing hearing impairment include:
- Otosclerosis
- Usher’s syndrome
- Pendred syndrome
Ototoxicity
Some medications or drugs can cause damage to the inner ear or hearing nerve. This is called ototoxicity and it can affect both hearing and balance. The exact way ototoxicity causes damage is not fully understood. Some types of medications may be more ototoxic than others. It is also dependent on the dosage and the duration of time that the medication is used.
Some chemotherapy drugs and strong antibiotics are ototoxic, such as gentamicin, streptomycin and neomycin. Hearing loss usually occurs in the very high pitches (frequencies) first, as they are not important for speech and language. If undetected, hearing loss can progress to affect the speech frequencies.
Call Hearing Health Centers at (712) 262-7774 for more information or to schedule an appointment.
