Understanding Hearing Loss

Hearing Facts

By Elizabeth Brassine, Au.D.H

Let’s start with some facts (NIDCD, 2013): one in five Americans 12 and older experiences hearing loss severe enough to hinder communication. Nearly 50% of adults ages 75 and older have hearing impairments. Hearing loss is the third most prevalent chronic condition in older Americans after hypertension and arthritis. About 26 million Americans between the ages of 20 and 69 have high frequency hearing loss due to exposure to loud noises at work or in leisure activities. Tinnitus (“ringing in the ears”) affects up to 50 million Americans. Tinnitus is currently the number one service-connected disability for veterans from all service. If you have hearing loss, you’re not alone. In fact, the World Health Organization estimates that 360 million people worldwide have “disabling hearing loss.”

How Hearing Works

When we become aware of a sound in our environment, it is the result of a sequence of events. The outer ear-sound travels through the pinna, what we see on the side of our head, which collects and funnels sound into and down the ear canal, striking the eardrum and causing it to vibrate. The middle ear-vibrations from the eardrum cause the ossicles (the three smallest bones in the body) to vibrate which, in turn, send the information onto the inner ear. In the inner ear, the movement of the hair cells sends electrical impulses through the auditory nerve to the hearing center of the brain, which translates them to sounds the brain can recognize.

Causes of Hearing Loss

Something can go wrong along that whole auditory pathway, therefore many things can cause our hearing system to stop functioning properly. The main causes are the aging process, noise exposure, infections, a variety of diseases such as Meningitis, injuries to the head or ear, birth defects, genetics, and ototoxic reaction to drugs or cancer treatment (i.e. certain antibiotics, chemotherapy, etc.).

How Hearing Loss Occurs

To understand why hearing loss is pervasive, it’s important to understand how hearing loss happens. Hearing loss happens when any part of our delicate hearing system stops working properly, whether it’s due to damage or deterioration. The most susceptible and common parts to break down are the microscopic stereocilia, the thousands of tiny hair cells that detect and send sound impulses to the brain. When these tiny hair cells become injured, diseased or die naturally, the result is sensory hearing loss. This is by far the most common type of hearing loss. When the microscopic stereocilia (hair cells) in your cochlear (inner ear) are damaged, they will not send complete signals to your brain, causing you to be unable to understand the consonants (more typical than vowels) within words. For example, the word “TOOTHBRUSH” may sound like “OO-BRU.” Healthy hair cells stand erect and are able to accurately detect sound waves and send impulses to the brain to correctly identify the word spoken. Damaged hair cells are limp and will no longer stand erect. They are therefore unable to properly detect sounds waves or send the correct information to the brain to identify.

How Hearing Loss Can Impact Your Life

If you think you hearing loss is inconsequential, you should know that studies have linked untreated hearing loss to significant issues such as: diminished psychological and overall health, impaired memory and ability to learn new tasks, reduced alertness and increased risk to personal safety, avoidance or withdrawal from social situations, social rejection and loneliness, fatigue, tension, stress and depression, irritability, negativism and anger, reduced job performance and earning power (from Better Hearing Institute, 2013).

What Hearing Loss is Like

You can’t recreate a hearing loss simply by plugging your ears. A person with normal hearing can hear quiet, medium and loud sounds that vary from low pitch (bass) to high pitch (treble). But when you have hearing loss, you often lose the ability to hear higher pitched sounds first, such as certain consonants like T, K, S, F, SH and TH. Even though you still may be able to hear the stronger, lower pitch vowel sounds, this is why “I hear, but cannot understand” is a common complaint.

Help is Available

If you think you or someone you know has hearing loss, the next step is an easy one––confirm it by seeing an Audiologist. Just as every person is unique, every hearing loss and hearing need is unique too. Consult an Audiologist who is trained to inspect your ear canal, accurately measure your hearing loss, assess your unique needs and make a recommendation that takes all this personal information into account.

Elizabeth Brassine is a Doctor of audiology and owner of Hearing Services of McKinney.