Hearing and Hearing Loss

What you need to know...

"I can hear just fine. My wife just mumbles. . ." "I just have wax in my ears. . ." "I hear but don't understand. . ." "When I turn up the volume, I don't hear any better. . ."

Do these comments sound familiar?

In this section, we hope to educate you on why these are common complaints heard in our office. In order accomplish this, we first must discuss how we hear.

How sound Travels Through the Ear:

The physical anatomy of the ear is precisely shaped to capture sounds and amplify them. Simply put, this is how it all works.

1. Sound waves are picked up by the outer ear, which is made up of the earlobe (pinna) & the ear canal.
2. Sound is funneled through the ear canal to the eardrum (tympanic membrane), which vibrates when the sound waves touch it.
3. The vibrations are picked up by the three tiny bones, commonly known as the hammer, anvil and stirrup. These bones transmit the sound vibrations to the inner ear.
4. The vibrations then reach the cochlea, a snail-shaped organ that is fluid-filled.
5. The vibrations cause waves in the fluid, setting thousands of tiny hair cells in motion.
6. The hair cell movements cause electrical impulses to travel along the auditory nerve to the auditory cortex of the brain.
7. The brain decodes and interprets the electronic impulses, allowing individual speech sounds to become recognizable words.

TRUELY AMAZING!!!

Disruptions in the above pathway cause hearing loss. Hearing loss comes in two main types, Conductive or Sensorineural. Here are brief explainations of each:

Conductive Hearing Loss
This type of hearing loss is a condition of the outer and/or middle ear (outer: pinna & ear canal. Inner: eardrum, middle ear cavity, ear bones). It occurs when sounds from the outside world cannot be transmitted normally through the ear canal and/or middle ear to the nerve cells of the inner ear. Conductive hearing loss can be temporary or long term. The most common causes of this hearing loss type are a build-up of wax in the ear canal, fluid in the middle ear space (common in children), perforated eardrums, or damaged or defective middle ear bones (ossicles).

Most conductive hearing losses can be medically or surgically treated. If the conductive hearing loss cannot be resolved for some reason, hearing aids can do a lot to compensate for the loss of loudness.

Sensorineural Hearing Loss
Sensorineural hearing loss is the most common form of hearing loss. It happens when some of the delicate hair cells inside the cochlea get damaged and are unable to transform the sound vibrations into electrical signals. Sensorineural hearing loss can be caused by long-term exposure to loud sounds, but the primary cause is the natural process of aging.

Once sensorineural hearing loss sets in, the condition may continue to worsen and will in most cases, be permanent. Typical symptoms are a loss of loudness and difficulties understanding (clarity) speech.

A person can have both conductive AND sensorineural hearing loss. When this occurs, the loss type is called "mixed."

"Why can I hear but not understand?"
Clarity of speech degrades when consonant sounds are not heard. Consonants provide clarity to speech, while vowels provide volume. When a person has hearing loss in the higher pitches, consonants are harder to hear. As a result, words "jumble" together and are no longer heard clearly.

To illustrate why consonants are more important than vowels, consider the following sentences. The first is missing vowels, and the second is missing consonants. Which one is easier to figure out?

1. CONSONANTS ONLY

Cnsnnts r mr mprtnt thn vwls.

2. VOWELS ONLY

Ooa ae oe ioa a oe.

Did you figure out the sentence?? It was "Consonants are more important than vowels." I'll say!