Anatomy of the Ear and Hearing Loss

Uploaded by MiracleEarExperience on 21.02.2011

Understanding the anatomy of your ear and how it works can help you better understand
hearing. Our ears are comprised of three parts: the outer ear, the middle ear, and the inner
ear. Each part plays a very important role in how we hear sound.
Think of sound as a series of vibrations. These vibrations are similar to the ripples
or waves that are made when you throw a stone into the water, but unlike the water waves,
they are invisible and travel in all directions around you. These waves are captured by the
pinna. It is similar to a catcher's mitt. The sound vibrates down the ear canal to the
ear drum, which begins to vibrate. The sound then passes through the three bones in the
middle ear cavity, which are the malleus, incus, and stapes. These are the smallest
bones in the human body. You may remember them in school as the hammer, anvil, and stirrup.
Now the sound goes through yet another window, and enters the cochlea. The cochlea is a snail-shaped
organ about the size of an aspirin. If you could unwind the cochlea, you would see approximately
20,000 sensory cells commonly referred to as "hair cells." As the sound goes through
the cochlea, it moves the fluid which moves the hair cells, sending thousands of elecrical
impulses up the auditory nerve to the opposing side of the brain. What you hear on your left
ear is primarily processed through the right brain hemisphere. What you hear on your right
ear is processed through the left brain hemisphere.
Hearing Loss can occur anywhere along this path. There are two kinds of hearing loss.
A Conductive loss is when the sound can't get to the cochlea for the nerves to do their
job. Common types of Conductive loss include excessive cerumen, or wax buildup, foreign
object in the outer ear, perforation or tear of the ear drum, or excessive fluid buildup
in the middle ear. Most of these hearing losses have medical or surgical treatments.
The second and most common type of adult hearing loss is Sensorineural Hearing Loss, which
can be caused by noise damage, the aging process, or other environmental factors. This type
of hearing loss is a result to damage to the inner ear. In a damaged cochlea, hair cells
are broken or gone, and can therefore no longer pick up sound or transmit it to the brain.
Typically, the hair cells tuned to high pitches become damaged first, because they are the
first to encounter sound waves.
Think of it this way: You have a ten-story building with steps between the floors. What
steps will get worn out first? Probably the first few floors. Hearing Aids are the only
course of action to help you with this type of hearing problem. Hearing aids will not
slow the progression, and will not cure you of the loss, but will help serve you to better
hear and understand, and with long term use, are proven to help maintain critical speech
recognition skills. A thorough hearing evaluation will help us to assess your hearing needs.