Hearing Loss

Anatomy of the Ear

Before explaining how hearing aids help the different types of hearing losses, it’s first important to understand how hearing works. The best place to start is inside the ear. It is the place where many complex and delicate functions combine to create what we call hearing. Your ear is an amazing organ that can perceive sounds from barely audible to very loud at frequencies or pitches of 20 to 20,000 Hz. It can pinpoint the direction of a sound source to an amazing degree of accuracy.

The human ear consists of three parts: the outer ear, the middle ear, and the inner ear.

Hearing Loss

The outer ear includes the visible part of the ear (pinna) and the ear canal. Sound is collected and directed through the ear canal.
The middle ear is an air-filled space separated from the outer ear by the eardrum. The middle ear contains three small bones (ossicles), which make up the ossicular chain. These bones connect the eardrum to the inner ear.
The portion of the inner ear responsible for hearing is called the cochlea. It is full of fluid and has thousands of tiny nerve fibers.

Additional terms

External auditory canal - part of the outer ear, a one-inch long, one-quarter inch diameter tube that ends at the eardrum. Its shape helps to boost speech frequencies.
Eardrum or tympanic membrane - a membrane about 1/3 of an inch in diameter that stretches across the inner end of the external ear canal. It vibrates in response to sound waves and forms the boundary between the outer ear and middle ear.
Cochlea - converts sound waves to nerve impulses through movement of thousands of tiny hair cells.
Acoustic hair cells - located inside the cochlea, these convert mechanical sound waves into electrical signals.
Auditory nerve - transmits the electrical signals from the acoustic hair cells from the inner ear to the brain.
Brain - processes the electrical signals from the auditory nerve that we interpret to be "sound."

Symptoms of Hearing Loss

Hearing loss is gradual, therefore, it may be hard for a person to notice symptoms until it is brought to their attention. From this point, he or she may start to notice that higher pitches, such as children and women’s voices, start to disappear. Following this change, he or she may start to notice symptoms including:

• Hearing but not understanding
• Turning up the volume on the TV
• Reading lips in order to understand speech
• Difficulty hearing environmental sounds such as crickets or birds
• Difficulty understanding conversation in groups and crowds
• Strained personal relationships
• Social withdrawl
• Fatigue and stress

Hearing Loss: Diagnosis and Treatment Information

Hearing loss affects millions of Americans, though very few seek treatment. An estimated one-quarter of Americans between the ages of 65 and 75 and around three-quarters of those older than 75 have some degree of hearing loss. Most people do not understand exactly how or why it is that they are having a harder time understanding conversations or hearing the television.

Over time, the wear and tear on your ears from noise contributes to hearing loss by damaging your inner ear. Doctors believe that heredity and chronic exposure to loud noises are the main factors that contribute to hearing loss. Other factors, such as earwax blockage, can prevent your ears from conducting sounds as well as they should. There are many different types of hearing loss and many different treatments used to help these losses.

You can't reverse hearing loss. However, you don't have to live in a world of quieter, less distinct sounds. You and your doctor or hearing specialist can take steps to improve what you hear.

Types of Hearing Loss

• Conductive Hearing Loss
• Mixed Hearing Loss
• Sensorineural Hearing Loss

Conductive Hearing Loss

This type of hearing loss is the result of a disorder affecting the outer or middle ear, such as ear infections associated with fluid in the middle ear space. Middle ear infections are the second-most common reason children visit a doctor. Generally, when children have middle ear infections with fluid in their ears, they have an accompanying hearing loss. Other common causes of conductive hearing loss include excess wax, foreign bodies or problems with the three bones in the middle ear.

Other Causes- Other causes of conductive hearing loss can include the perforation of the ear drum, fractured bones in the middle ear, or tumors. Depending on the type and severity of the problem, different treatments will be proposed. Perforated ear drums, for example, will often heal by themselves.
In many cases, conductive hearing loss can be treated either medically or surgically, and may not be permanent.

Sensorineural Hearing Loss

This is hearing loss that is the result of a disorder of the inner ear called the cochlea, or the auditory nerve that transmits an auditory signal. There are many different causes of sensorineural hearing loss including congenital infections, medications, over-exposure to noise and genetic factors. In half of the cases of hearing loss present at birth, called congenital hearing loss, the cause is not determined. Sensorineural hearing loss is usually permanent.

Other Causes - Age-related hearing loss (presbyacusis). This is the natural decline in hearing that many people experience as they get older. It's partly due to the loss of hair cells in the cochlea;
Acoustic trauma (injury caused by loud noise) can damage hair cells; certain viral or bacterial infections such as mumps or meningitis can lead to loss of hair cells or other damage to the auditory nerve; Ménière's disease, which causes dizziness, tinnitus, and hearing loss; certain drugs, such as some powerful antibiotics, can cause permanent hearing loss. At high doses, aspirin is thought to cause temporary tinnitus - a persistent ringing in the ears. The antimalarial drug quinine can also cause tinnitus, but it's not thought to cause permanent damage; Acoustic neuroma. This is a benign (non-cancerous) tumour affecting the auditory nerve. It needs to be observed and is sometimes treated with surgery. Other neurological (affecting the brain or nervous system) conditions such as multiple sclerosis, stroke, or a brain tumour.

Mixed Hearing Loss

Sometimes a conductive hearing loss occurs in combination with a sensorineural hearing loss. In other words, there may be damage in the outer or middle ear and in the inner ear (cochlea) or auditory nerve. When this occurs, the hearing loss is referred to as a mixed hearing loss.

Children and Hearing Loss

Parent Involvement

As a parent, involvement in your child's overall development is very important. And this is especially true when your child has a hearing loss. The more time, patience, love and support you provide, the easier it will be for your child to realize his or her fullest potential. It will also assist other important developmental factors, such as verbal and social interaction. If your child is of school age, you should schedule time to talk with teachers and other school staff. Be sure they know what special care is needed for a child with hearing loss in a noisy environment, such as in a classroom or lunchroom. Teachers and other staff should be familiar with the value of speaking directly to your child, and helping him or her to use lip-reading to understand what's being said.

Right From the Start

From the moment of birth, hearing plays a critical role in child development. Through hearing, infants learn to interpret the world around them. They startle when hearing loud sounds, and quickly and naturally learn to recognize their parents’ voices.
As babies grow, hearing becomes essential to the development of their receptive and expressive spoken language skills. Approximately three in every 1,000 children in the U.S. are born with some type of hearing problem. With early detection and intervention programs, these children can get the help they need to hear – right from the start. Early diagnosis and treatment Professionals agree that the first few years of life are the most critical period for speech and language development. During this time, a child’s social, emotional, and cognitive skills are also being formed. An undetected or untreated hearing loss can have a negative impact in all developmental areas. Because of the plasticity of the developing brain, both audiology and child development experts endorse early identification and remediation of hearing loss in infants.
Thanks to advances in medical technology and the efforts of Hearing Care Professionals, hearing loss can now be detected even before a newborn leaves the hospital. A complete diagnosis and treatment program can then follow in the coming weeks and months, taking full advantage of this critical time in an infant’s development, and ensuring that his or her full potential is realized.

Quality of Life

Due to improvements in both hearing aid technology and patient counseling, the treatment plan for a child with hearing loss today does not necessarily present the challenges of the past. Better technology, education and a greater understanding of child development has provided more opportunities now than ever before.
As you progress along this path of discovery, remember that your situation is specific to your family and child. It would be a mistake to use other children and families as benchmarks for your child's progress. Find your own pace. Be pleased with the positive strides that occur. Some developmental steps will take more time, others will occur quickly.
Remember that your child looks to you for validation and reinforcement. Try not to apply additional pressure by setting him or her up to the same standards you may have experienced while growing up, or those experienced by other children. Once again, time, patience, love, and support are most important.

Encouraging Your Child

Counseling Issues

After the child is fitted with hearing aids, there may be a period of adjustment that follows. Part of this process may include counseling for both the child and family members. Informal counseling may also be helpful. Talk to parents of other children with hearing loss in the community. These parents are experienced. They understand and have encountered the same challenges and opportunities as you. They may have suggestions and additional resources to recommend. Forming a "support team" of parents and educators will go a long way in facilitating a child's social and scholastic progress.

Teachers, therapists and others who interact with school-age children with hearing loss should be kept informed about the child's progress and particular challenges. It's important to offer patience, attention, love, and support to help the child continue to develop along with his or her classmates.
The first time your child wears their hearing aids, he or she may need some time to adjust to all the sounds surrounding them. This process might be a bit longer than you expect, but keep a positive and relaxed attitude. Engage your child in exploring their new environment. With encouragement, the hearing aids should be accepted and successfully worn by your child.

When Your Child Says "I don't want to wear them today."

There will likely be times when your child, for whatever reason, simply won't want to wear his or her hearing aids. When this happens, it is best to remain calm and try to find out the reason. Try to get as many details as possible and report them to your Hearing Care Professional. Begin by exploring these questions:

• When or where does your child express that they do not wish to wear their hearing aids?
• Is their outer ear or ear canal itchy and irritated?
• Are they uncomfortable because the earmold doesn't fit properly?
• Are there certain situations - noisy environments for example - where your child doesn't like wearing them?
• Is your child uncomfortable wearing them for personal reasons?

Remember that for a child wearing hearing aids for the first time, there can be a normal period of adjustment before any issues of personal comfort and emotional security are resolved. It is important to be patient and explain the benefits of wearing the aids to a child who is old enough to understand. Once you discover the problem, you can work to solve it together. The most important thing is to get the hearing aid back on your child quickly.
For infants and very small children who try to remove the hearing aid, parents should be firm and place them back in the ear as soon as possible - do not allow the child to keep removing them.

Testing For Hearing Loss

In testing for hearing loss, a Hearing Care Professional will administer a painless, quick and safe test that checks your ability to recognize tones and everyday words at different volume levels. The data produces a unique hearing pattern that is recorded on a chart called an audiogram. The Hearing Health Care Professional uses the data from your audiogram to determine whether you might benefit from hearing aids or whether medical treatment is indicated.
Hearing loss is especially prevalent in older people. If you are over age 50, consider a yearly hearing test as an important part of your physical checkup.

Checklist

The following questions will help you determine if you, or a loved one, should have a hearing test performed by a Hearing Health Care Professional. There are two questionnaires to choose from. One is for you to answer about your own hearing. The other is about the hearing of a loved one. Remember, detection of a hearing problem is the first step to improving your hearing health.

Questionnaire: Do I have a hearing loss?

• Do people always comment that the volume on your TV or radio is too loud?
• Have you missed visits and calls from people because you didn't hear the doorbell or telephone ringing?
• Do you have trouble following conversation in crowded or noisy settings?
• Do people seem to mumble and not speak clearly during conversation?
• Do people tell you that you speak too loudly in conversation?
• Do you frequently ask people to repeat themselves?
• Do your friends and family suggest that you have a hearing problem?
• Do you have a difficult time understanding the words of popular songs when listening to the radio?

Questionnaire: Does someone I know have a hearing loss?

• When you come to visit does the person you know hear your knock on the door or the doorbell?
• Does the person you know complain about having a difficult time hearing on the telephone?
• Does the person you know always ask you and others to repeat yourselves?
• In crowded settings, does the person you know complain about not understanding what people are saying?
• Does the person you know always turn the volume on the TV or radio up to an uncomfortable level just to hear a program or music?
• Does the person you know often complain of ringing in the ears?

If you answered "YES" to any of these questions, you or your loved one may want to have a hearing test to determine if there's some degree of hearing loss. If you suspect a hearing loss, email or call ClearValue Hearing to activate your FREE account and to find a Hearing Healthcare Professional in your area.

References

BUPA. 1996-2007. Retrieved October 25, 2007 from: http://hcd2.bupa.co.uk/fact_sheets/Mosby_factsheets/Hearing_Loss.html

Mayo Foundation for Medical Education and Research. 1998-2007. Retrieved October 25, 2007 from: http://www.mayoclinic.com/health/hearing-loss/DS00172

Siemens Hearing Instruments. 2007. Retrieved October 25, 2007 from: http://www.siemens-hearing.com

UCSF Medical Center. 2002-2007. Retrieved October 25, 2007 from: http://www.ucsfhealth.org/childrens/medical_services/audio/hearingloss/conditions/hearingloss/signs.html