What Harms the Ears?
Deafness due to cilia damage in the cochlea is not the only outcome of assaults on the ear. Each of the following insults—an appropriate medical term that reminds us hurtful language also assaults the ears and the nervous system—may affect more than one part of the ear. Parents, teachers, and childcare workers can teach children how to care for and protect their ears. Harm to the ears affects behavior because the ear, especially the right ear, controls the amount of sound energy reaching the left hemisphere of the brain.
LOUD SOUND—affects the stapedius muscle, the cilia, the vestibule, and the brain
Harmful sound includes (1) very loud sound, such as an airplane engine or a professional singer’s voice; (2) low-frequency sound like the “boom boxes” in some speaker systems and the amplifiers used at concerts; (3) sudden loud sound, such as fireworks or bombs or weapons firing nearby, can cause what today is called post-traumatic stress disorder (PTSD) and used to be called, perhaps more accurately, “shell shock”; (4) unusual loud sound affects the developing fetus. For example, the hearing of the fetus can be damaged if the mother moves to a house near an airport, or flies in an airplane, or uses power tools or other noisy machinery while pregnant. Young children are especially vulnerable to loud sound and many parents do not realize they must protect their unborn and newborn infants’ ears. Even the incubator’s hum in an intensive care nursery can harm newborns’ ears.
CHEMICALS—affect the stapedius and eardrum muscles, endolymph in the inner ear, and possibly other tissues
Certain chemicals affect the stapedius, including some medications (e.g., Aspirin, prednisone, some chemotherapy chemicals, antipsychotics, and antidepressants). However, Aspirin can help to protect the ears during chemotherapy. All of the drugs called “recreational” or “street” drugs harm the ears. Toxic gases are airborne chemicals that can harm the ears, too (e.g., smoke from cigarettes, smoke from a petroleum fire, diesel and gasoline vapours, the fumes from burning residues, etc.). Much more needs to be learned about how chemicals and the interaction of multiple chemicals affect the ears.
OXYGEN DEPRIVATION—affects the stapedius and eardrum muscles and inner ear
A lack of oxygen, such as infants may experience during a difficult birth; carbon monoxide poisoning that removes oxygen from the blood; near drowning or near suffocation; or even not getting enough exercise to pump oxygenated blood through the ear can weaken the muscles of the middle ear.
INFECTIONS—may affect all or any part of the middle and inner ear
One of the reasons the disease mumps is so serious is that it can destroy the acoustic nerve. But other infections carry a similar risk, whether they are bacterial, viral, or yeast. People who spend a lot of time under water, such as divers and swimmers, or those who swim in polluted water are at risk for infections of the outer ear that can migrate to the middle ear. People with throat infections may develop a secondary infection in the middle ear, which can spread to the mastoid cavity or to the inner ear.
OBJECTS IN THE EAR CANAL—may damage the eardrum; may cause infection
Sometimes children put small objects into an ear, such as a dried bean or a small toy part. People with growths of bone or tissue (tumors), depending on where these occur, may find their hearing affected by the growth or by treatment to restrict or remove it. Instruments used for cleaning the ear, such as Q-tips, can also cause damage and should be used with great caution or not at all. Never try to fix the problem at home; take your child to the doctor, to a clinic, or to the hospital.
TRAUMA—Surgery, such as putting in drainage tubes for children with frequent ear infections, may affect any or all parts of the ear; blows to the head can damage the outer ear, the middle ear including the stapedius muscle, and/or the inner ear. Physical trauma, such as surgery or blows to the head occurring through beating, fighting, a fall, a sporting accident, or an automobile accident, can harm the ear. Most doctors still are unaware of the effects on behaviour of damage to the ear, and will be looking primarily for skull, vision, and brain-related outcomes to head trauma. Violent motion, such as on some amusement park rides, and air pressure changes, such as during take-off and landing during air flights and that scuba divers experience, also can harm the ear.
HORMONAL CHANGES—Hormonal changes, such as those triggered by tumors in the brain, can affect hearing. Decreasing amounts of hormones in the body due to aging can affect hearing. This is an area for research as it appears that ear dysfunction can disrupt hormone production, creating a negative loop that further harms the ear.
ABNORMAL AND NORMAL AGING—The ears change with age and with over-stimulation. Too much sound can deafen the ears. Factory noise and urban noise have an effect of cumulative damage to the ears. Workplace noise is a hazard not only to hearing but to mental health. Many older people have enough cilia damage to require hearing aids. Hearing aids were invented much later than glasses, although “ear horns” that focus sound to the outer ear may have been used from ancient times. Like blindness, total deafness is very hard to correct.