Normal Ear Function
- Sound is transmitted through the air as sound waves from the environment. The sound waves are gathered by the outer ear and sent down the ear canal to the eardrum.
- The sound waves cause the eardrum to vibrate, which sets the three tiny bones in the middle ear into motion.
- The motion of the three bones causes the fluid in the inner ear, or cochlea, to move.
- The movement of the fluid in the inner ear causes the hair cells in the cochlea to bend. The hair cells change the movement into electrical impulses.
- These electrical impulses are transmitted to the hearing (auditory) nerve and up to the brain, where they are interpreted as sound.
The Outer Ear
The part of the outer ear that we see is called the pinna, or auricle. The pinna, with its grooves and ridges, provides a natural volume boost for sounds in the 2000 to 3000 Hz frequency range, where we perceive many consonant sounds of speech.
The ear canal, also called the external auditory meatus, is the other important outer ear landmark. The ear canal is lined with only a few layers of skin and fine hair, and is a highly vascularized area. This means that there is an abundant flow of blood to the ear canal. Wax (cerumen) accumulates in the ear canal and serves as a protective barrier to the skin from bacteria and moisture. Ear wax is normal, unless it completely blocks the ear canal.
The Middle Ear
The eardrum, or tympanic membrane (TM), is the dividing structure between the outer and middle ear. Although it is an extremely thin membrane, the eardrum is made up of three layers to increase its strength.
The ossicles are the three tiny bones of the middle ear located directly behind the tympanic membrane. These three bones form a connected chain in the middle ear. One of the bones is embedded in the innermost layer of the tympanic membrane, and the third bone is connected to a membranous window of the inner ear. The ossicles take mechanical vibrations received at the tympanic membrane into the inner ear.
The Eustachian tube is the middle ear’s air pressure equalizing system. The middle ear is encased in bone and does not associate with outside air except through the Eustachian tube. This tubular structure is normally closed, but it can be involuntarily opened by swallowing, yawning, or chewing. It can also be intentionally opened to equalize pressure in the ears, such as when flying in an airplane. When this happens, you might hear a soft popping sound.
The Inner Ear
The inner ear is an organ located deep within the temporal bone, which is the bone of the skull on both sides of the head above the outer ear. The inner ear has two main structures: the semicircular canals and the cochlea.
- Semicircular canals – These structures do not contribute to hearing, but assist in maintaining balance as we move.
- Cochlea – This is the hearing organ of the inner ear, which is a fluid-filled structure that looks like a snail. The cochlea changes the mechanical vibrations from the tympanic membrane and the ossicles into a sequence of electrical impulses. Sensory cells, called hair cells, bend in the cochlea as the fluid is disrupted by the mechanical vibrations. This bending of the hair cells causes electrical signals to be sent to the brain by way of the auditory nerve. The cochlea is arranged by frequency, much like a piano, and encodes sounds from 20Hz (low pitch) to 20,000Hz (high pitch) in humans.
Hearing Loss
Why not value your hearing as much as you value your vision? It’s a precious resource that needs to be monitored along the way. Your hearing keeps you connected to the world. If you are asking loved ones to repeat themselves, you may have lost some hearing. Or, if people tell you that you need a hearing test, believe them, and please do it. Often, others note that your hearing has declined before you do. They end up having to repeat what they say or endure very high volume on your TV. That’s unfortunate when there are so many great choices for solving hearing issues today. Also, we’ve learned that hearing loss is associated with mental decline, so if you treat the hearing loss, you’re keeping your brain exercised!
Hearing loss is an AGE-OLD problem, not just an old-age problem. Some people are born with hearing loss, others develop hearing loss along the way. There’s a big increase in hearing loss in our forties. Loud music, noise in the workplace and high volume sounds such as gunfire, leaf blowers and power tools can damage your hearing. Certain medications, although necessary, may have hearing loss as a side effect. Some families share a tendency for hearing loss as they mature.
Dr. Leslie Lesner and Dr. Abby Holauchock, Doctors of Audiology at Lesner Hearing Center, will give you a complete hearing test and will discuss the results with you in plain language. They will recommend hearing instruments that are appropriate for your hearing issues, your lifestyle, your dexterity and your budget.
Improving a hearing loss is more than just turning up the volume across the board. Fitting hearing aids requires sophisticated measures of your hearing, an inventory of the demands you put on your ears, proper strategies for meeting those demands, an adjustment period and fine-tuning. Dr. Lesner and Dr. Mott specialize in the hearing problems of children, adults and senior citizens. They educate their clients so that they can take full advantage of today’s hearing technology whether that means simple devices with no adjustments or devices with wireless capabilities to integrate with cell phone, iPad, TV, etc. The result is improved hearing in all environments. And that means a better quality of life!
Let Lesner Hearing Center at 5232 Dawes Avenue in Alexandria help you pinpoint and manage your hearing issues. Call 703-820-3800 today or fill out our contact form to schedule your FREE HEARING EVALUATION. And see the video on our home page to learn a bit more about our practice.