As one of the five senses, hearing gives us information about our surroundings. Loss of hearing, even partial loss, can leave us disoriented and isolated. Here are five facts about hearing and hearing loss:

Causes of Hearing Loss

The ears have three sections – the outer ear, the middle ear, and the inner ear. The outer ear (the portion of the ear we see) funnels and directs sound waves into the ear canal.

The middle ear includes the eardrum, which vibrates as sound waves strike it. As the eardrum vibrates, it transmits vibrations to three interconnected bones, the hammer, the anvil, and the stirrup. These bones, in turn, vibrate the oval window, which covers the entrance to the cochlea. The middle ear functions to amplify the vibrations between the eardrum and the oval window by as much as 20 times.

The inner ear consists of the cochlea, a fluid-filled spiral tube with tiny, sensitive hairs inside. The vibrations on the oval window cause pressure changes in the cochlear fluid. The pressure changes cause movement of the hairs. The hairs convert the pressure changes caused by the sounds into electrical impulses that are transmitted along the auditory nerve to the brain. The brain decodes the electrical impulses as sound.

There are two primary causes of hearing loss:

  1. Age: Age-related hearing loss is also called presbycusis. Gradual hearing loss is common as we age, with nearly 50% of those over 75 years old suffering some loss of hearing. The most common cause of age-related hearing loss is loss of sensitivity of the hairs inside the cochlea.
  2. Loud Noises: Exposure to loud noises can cause hearing loss in people of any age. In fact, high-frequency hearing loss due to exposure to loud noises affects 26 million Americans between 20 and 69 years of age. Most frequently, hearing loss occurs because loud noises cause damage to the hairs inside the cochlea. Occasionally, hearing loss occurs because loud noises cause damage to the eardrum or the three bones of the middle ear.


Although not totally unexpected, nutrition has a surprising effect on hearing. Foods high in potassium can aid the inner ear to transmit sounds. Folic acid can help slow the onset of age-related hearing loss and zinc can aid the treatment of tinnitus.

Hearing Protection

Because loud noises can cause hearing loss, hearing protection is advisable for those who are exposed to loud noises such as gunfire, construction machinery, and power tools. Hearing protection can be passive, such as earplugs, or dynamic. Dynamic hearing protection devices sense incoming noises. At low levels, the hearing protection device allows or even amplifies the sounds. When the dynamic hearing protection device senses loud noises, it blocks the sound transmission, thereby protecting the ear.

Hearing Tests

An audiologist is a licensed professional who is trained to diagnose and treat hearing disorders. Audiologists can administer hearing tests. During a hearing test, the patient listens to sounds of varying frequencies and volumes through headphones and identifies which sounds the patient can hear and which he or she cannot hear. The results of a hearing test can not only identify loss of hearing, but it can identify the frequencies where the hearing loss has occurred. In the event that hearing aids are needed, tests help the audiologist assists you in selecting a hearing aid and programs it for your personal use.

Hearing Aids

For those who have suffered some amount of hearing loss, a hearing aid may be useful to amplify sounds. While some hearing loss sufferers may be concerned about the appearance of hearing aids, some models of small hearing aids are virtually invisible. Small hearing aids come in a variety of styles, including small hearing aids that fit into the ear canal and small hearing aids that rest partly in the canal and partly in the outer ear. Small hearing aids can also fit over the ear, with a small receiver that fits inside the ear canal.

Hearing aids serve a number of purposes to aid someone with hearing loss:

  • Filter out background noise by suppressing loud noises and noises at certain frequencies
  • Amplify sounds
  • Selectively amplify certain frequencies associated with the human voice

Your hearing is important for your safety and comfort. Important enough to protect with hearing protection and assist with hearing aids.