More than 48 million people in the U.S. experience hearing loss, and the Center for Disease Control and Prevention estimates that, of this population, approximately 26 million suffer from permanent damage caused by excessive exposure to noise. So how does sound lead to hearing loss?
How the Ear Works
The ear is broken down into three parts: the outer, middle and inner ear. Soundwaves from your environment are captured by the outer ear and funneled into the ear canal, where they hit the eardrum. This creates a vibration, which travels through the three tiny bones in the middle ear.
The inner ear contains a structure called the cochlea. Shaped like a snail, the cochlea is lined with tiny hair cells and filled with fluid. The average person is born with about 16,000 of these hair cells. Unlike other hair on your body, once damaged these cells cannot be repaired or regrown.
When the sound vibration reaches the inner ear, it causes the liquid in the cochlea to move, bending the tiny hair cells. As they bend, the hair cells create electrical signals.
The auditory nerve then carries the electric signal from the inner ear to the brain, where it is interpreted as sound.
Damage to the Inner Ear
Loud noises, such as one extremely loud sound or continuous loud sounds over a long period of time, can damage the cells and membranes of the inner ear. Over time, loud noises overwork the hair cells within the cochlea, causing them to die.
After leaving a concert, temporary hearing loss is common. This includes:
- Not being able to hear whispers
- Sounds seeming muffled
- Hearing a ringing in the ear (tinnitus)
Your hearing will return to normal after a few hours or days. While the loud noise can bend the hair cells, they are often able to straighten again after a short recovery period.
Repeated exposure will eventually destroy too many hair cells. You can damage up to 30 to 50 percent of your hair cells before you notice a change in your hearing. Unfortunately, by the time your hearing loss can be measured on an auditory test, the damage is permanent.
Damage to the Auditory Nerve
Loud noises can also damage the nerve responsible for carrying electrical signals from the inner ear to the brain.
Damage to the auditory nerve creates a condition known as hidden hearing loss, which makes it difficult to understand speech in noisy environments, but does not show up on a traditional hearing test.
Protecting Your Hearing
Avoiding loud noises and events can help prevent ear damage. If loud noises cannot be prevented, wearing proper hearing protection is the next best thing.
To learn more about protecting your hearing or to schedule an appointment for a hearing test, contact the experts at Torrance Audiology today.