How You Hear
Hearing begins when the outer ear, the visible portion of the ear that is on the outside of the head, channels sound waves down the auditory canal. This tube-like passageway is lined with tiny hairs and small glands that produce wax.
The middle ear lies at the end of the auditory canal. It is composed of the ear drum and three small bones, known by the layman as the hammer, anvil and stirrup. When sound waves hit the ear drum, it vibrates and, in turn moves the hammer. The hammer moves the anvil, which moves the stirrup, transmitting the vibrations into the inner ear. The middle ear functions to amplify sound, which is why significant hearing loss can result from any disruption in any of the parts.
The inner ear consists of the cochlea and the nerve of hearing. It converts sound waves into nerve impulses that travel to the brain via the movement of tiny cells. The brain, in turn, allows us to hear…as long as the message it is receiving is not distorted due to problems in the process just described.
Hearing Loss Facts & Statistics:
According to the National Institute on Deafness and Other Communication Disorders (NIDCD):
- Hearing loss is greater in men.
- Approximately 28 million Americans have a hearing impairment.
- Hearing loss affects approximately 17 in 1,000 children under age 18. Incidence increases with age: Approximately 314 in 1,000 people over age 65 have hearing loss and 40 to 50 percent of people 75 and older have a hearing loss.
- About 2 to 3 out of every 1,000 children in the United States are born deaf or hard-of-hearing. 9 out of every 10 children who are born deaf are born to parents who can hear.
- Ten million Americans have suffered irreversible noise induced hearing loss, and 30 million more are exposed to dangerous noise levels each day.
- Only 1 out of 5 people who could benefit from a hearing aid actually wears one.
- Three out of 4 children experience ear infection (otitis media) by the time they are 3 years old.
- At least 12 million Americans have tinnitus. Of these, at least 1 million experience it so severely that it interferes with their daily activities.
- Approximately 59,000 people worldwide have received cochlear implants. About 250,000 people would be good candidates for a cochlear implant. In the United States, about 13,000 adults and nearly 10,000 children have cochlear implants.
- Approximately 4,000 new cases of sudden deafness occur each year in the United States. Hearing loss affects only 1 ear in 9 out of 10 people who experience sudden deafness. Only 10 to 15 percent of patients with sudden deafness know what caused their loss.
- Approximately 615,000 individuals have been diagnosed with Ménière’s disease in the United States. Another 45,500 are newly diagnosed each year.
Cause of Hearing Loss
The truth is that there are several causes of hearing loss with “exposure to noise” ranking high among the reasons. The primary causes of hearing loss are:
- Exposure to noise
- Hereditary hearing loss
- Aging process
- Chronic ear disease
- Acute infections