“Your Weekly Checkup” is our online column by Dr. Douglas Zipes, an internationally acclaimed cardiologist, professor, author, inventor, and authority on pacing and electrophysiology. Dr. Zipes is also a contributor to The Saturday Evening Post print magazine. Subscribe to receive thoughtful articles, new fiction, health and wellness advice, and gems from our archive.
At a movie last night, my wife and I traded queries several times. “What did he say?” we’d ask each other. We’d heard the spoken words but they were uninterpretable sounds, failing to register meaningfully in our brains.
Hearing loss is a major cause of disability in the U.S., especially as the population ages. Approximately half of persons older than 60, and 80% of those older than 85, experience hearing loss severe enough to impact daily life. Impaired hearing is associated with increased rates of hospitalization, falls, dementia, depression, unemployment, lower income, and death. Annual health care costs for hearing impaired persons are considerably higher than for those with normal hearing. Hearing loss is the fourth leading cause of disability globally.
Hearing impairment can be of two types: conductive and sensorineural. Conductive hearing loss can result from simple wax build up in the ear canal or from more extreme conditions such as middle ear infection or fixation of bones in the middle ear (otosclerosis.) Medical or surgical treatment of conductive hearing loss often restores full hearing.
Sensorineural hearing loss results from cochlea (inner ear) dysfunction or damage to the cochlea’s nerves, caused by degenerative processes associated with aging, genetics, noise exposure, and drugs toxic to the ear, such as some antibiotics, chemotherapeutic or anti-inflammatory agents. Hearing loss can also be genetic, affecting about 1 in 1000 live births.
Hearing impairment in the adult (presbycusis) most often results from age and genetic related degenerative changes in the cochlea and the accumulated effects of exposure to noise and ototoxic drugs. It is usually bilateral, impacts higher frequencies, and reduces the ability to understand spoken words even if the sound is loud. My wife and I have this type.
Approximately 25% of U.S. adults have hearing loss from chronic exposure to loud noise. I often think of this when a car pulls alongside at a stop light with the radio blasting so loud I can hear it with the windows shut; or when people attend a concert with the sound amplifiers exploding; or ride for hours on a noise-shattering motorcycle. The blare damages delicate sensory hair cells of the inner ear that convert sound to neural signals for the brain to interpret. The damage can be temporary or permanent, depending on the extent of the noise exposure.
Hearing loss is also associated with smoking, diabetes, and obesity, suggesting that changes in blood vessels may play a role. Sudden sensorineural hearing loss, perhaps due to viral infection or a vascular or autoimmune event, is considered an emergency since steroids can be helpful in some instances.
For the hearing impaired, hearing aids can be useful, but often make spoken words louder, not necessarily more understandable. Cochlear implants can be used to bypass the impaired hair cells and electrically stimulate the auditory nerve.
Hearing is one of life’s critical functions. Protect yours by reducing contributing factors such as noise pollution and smoking. Consult an otolaryngologist for an evaluation if you have decreased hearing. Treatment can change your life.
My hearing was adversely affected after surgery. Does anesthesia sometimes cause hearing loss?
We contacted the American Society of Anesthesiologists (ASA) about your unfortunate experience. Dr. William Camann, an anesthesiologist at Brigham & Women’s Hospital and associate professor at Harvard Medical School, Boston, explains:
“Hearing loss is a very rare but known side effect of surgery and anesthesia. It may also develop after surgery in people taking certain drugs (for example, some antibiotics).
“The type of anesthesia and surgery being performed may influence the risk of developing hearing loss. Spinal (or epidural) anesthesia may change the circulation of fluid around the brain and spinal cord, causing some people to get a headache. It can also affect fluid within the ear, and may result in temporary or permanent hearing loss.
“Hearing loss has also been reported after cardiac surgery involving cardiopulmonary bypass [a heart-lung machine]. Although the cause is unknown, it is possible that ‘microemboli,’ or small particles, can move into the bloodstream during the bypass portion of the operation. These particles may travel to blood vessels of the ear, and have an effect on hearing in one or both ears. Blood pressure alterations during bypass surgery may be another factor.”
Dr. Camann adds that concerns about individual cases should be referred to the anesthesiologists and/or surgeons involved in the actual case.