HEARING CHANGES IN AGING PEOPLE WITH MENTAL RETARDATION
Author's note: This information is pertinent to many people with other developmental disabilities.
People who have mental retardation and other developmental disabilities are not only living productive lives within communities across the country, but they are also living longer. Like others who reach their later years, older people with developmental disabilities are at risk for acquiring a number of age-related chronic conditions. One of the more common conditions among older adults is hearing loss. Regular hearing evaluations are important to identify losses in hearing that make it difficult for older adults to communicate in work, social and interpersonal situations.
This fact sheet provides answers to frequently asked questions about age-related hearing loss, especially for people with developmental disabilities. It contains the information that families and service providers need to identify possible hearing loss and to support older adults who have this condition.
How does Hearing Typically Change With Age?
As people get older their hearing may change. The extent of these changes depends on factors like heredity, illness, accidents, and exposure to environmental noise.
Many older people lose sensitivity to sound meaning that if the sound were just louder everything would be fine. A more serious problem experienced by older people is losing the ability to hear certain pitches. Usually high-pitched sounds are lost first. This condition when it happens to older adults is called presbycusis. Speech may not sound clear and may be difficult to understand. For example, similar words may be confused, like "pat" and "bat" and "dinner" and "thinner." Speaking louder or turning up the volume on the TV will not necessarily help make speech easier to understand. That action may actually distort the sound. Also, some older people have problems processing auditory information particularly when there is noise in the background. It is not uncommon for a person to experience more than one of these problems at the same time.
Some older adults experience tinnitus, which often occurs with hearing loss. People may hear a ringing, buzzing, swishing or a clicking sound even though there is no such sound in the environment. Tinnitus has many possible causes, some of which are medically serious and some are not, including: damage to the inner ear, earwax, or high (or low) blood pressure. Tinnitus is hard to treat, and it can be hard to diagnose in individuals with developmental disabilities who may have difficulty in expressing themselves.
What Causes Hearing Loss?
Age-related hearing loss can be caused by a number of factors. Impacted earwax, infections, head trauma, and damage to the eardrum can cause conductive hearing loss, which reduces sensitivity to sound. Head trauma, drugs, diabetes, hypertension, noise, heredity, kidney failure, and coronary artery disease can cause sensorineural (nerve deafness) hearing loss, which results in the inability to hear certain sounds due to damage in the inner ear or cochlea. Problems with the auditory nerve and damage to the portion of the brain that processes auditory information can also make it difficult for people to understand what they hear. Older adults may have any one or a combination of these conditions.
Do People with Mental Retardation Experience Hearing Losses That are Different from Other Older Adults?
Research indicates that most people with developmental disabilities are as likely to develop age-related hearing loss as are other people. However, people with Down syndrome may experience hearing losses while in their early twenties or younger. Many people with Down syndrome have conductive hearing loss resulting from frequent middle ear infections in childhood. People born with malformations of the outer ear typically have very small ear canals that can be blocked by small amounts of earwax. Many people with Down syndrome, as well as people with other developmental disabilities, may have narrow ear canals.
How Can a Hearing Loss be Identified?
Changes in behavior should always be investigated. Observing changes in behavior and asking the right questions often help. Turning up the TV or radio volume very loud, speaking loudly, responding to questions inappropriately, or becoming confused in very noisy situations may indicate a possible hearing loss. People often blame their hearing problem on others (whispering or mumbling) or on the environment (loud music or traffic), but some people do realize that they don't hear as well as before.
For example, does a usually outgoing person slowly begin to isolate himself? When the world becomes too confusing some people will withdraw. Some behaviors may seem disruptive and inappropriate. Self-abusive behavior (e.g., head banging) could indicate frustration at not being able to hear or could be a response to an earache. A complete hearing evaluation performed in an office setting by a qualified professional, such as an audiologist certified by the American Speech-Language-Hearing Association (ASHA) is required to determine the extent of a hearing loss and to plan an appropriate course of action.
How Important is a Hearing Test for Adults who Have Mental Retardation?
Good hearing is important for everyone. A hearing loss can cause serious problems with communication and can lead to interpersonal problems at home and on the job. Because some hearing can be lost without our ever realizing that it is gone, a hearing test is the only real way to know if a person has a hearing problem. A hearing test is especially important for people with mental retardation to ensure they will have maximum use of their communication skills. Because some people with mental retardation have communication limitations, a mild to moderate hearing loss may affect them as much as a severe or profound hearing loss affects people without a cognitive disability.
A hearing test is also an important tool in determining a person's overall health. A hearing test can indicate the presence of other medical conditions, and this can be critical if the person is unable to report other symptoms. For example, a sudden hearing loss might indicate a transient ischemic attack (mini stroke), a head injury, or even low blood sugar.
Where Can a Hearing Test be Obtained?
Although hearing screenings are often available free of charge in the community, they are not a substitute for a complete hearing evaluation. An individual should have a comprehensive hearing evaluation conducted by an ASHA-certified audiologist. When indicated, a referral for appropriate medical evaluation will be made. It is a good idea to consult with physicians, audiologists, other families and consumer organizations for recommendations of a good hearing care specialist.
University or hospital hearing clinics are most likely to have the special equipment necessary to evaluate someone who may be difficult to test. Universities and medical schools with speech and hearing programs often have clinics open to the public. The American Speech-Language-Hearing Association (1-800-638-8255) will provide a listing of certified audiologists in your area. Be sure to check with your health plan before obtaining a hearing test to find out if it requires an initial referral from a general practitioner and if it specifies a certain provider.
What Information Does the Audiologist Need?
The audiologist will ask questions to find out the individual's overall health and functioning and the reasons for suspecting a hearing loss. This case history is a very important part of the audiological evaluation, especially for a person with a developmental disability. Information on the person's general health, vision, and typical activities will help the audiologist recommend devices and adaptive strategies if a hearing loss is found. Typical questions may include:
Because vision and hearing are both used to learn about people and the world, usable vision is especially important for anyone with hearing loss.
What Happens During a Hearing Test?
Hearing tests are usually conducted in sound-proof rooms. Testing will consist of listening to different pitched tones, as well as testing for speech understanding. Headphones are used to test each ear separately, or testing can be done through loudspeakers if wearing headphones is uncomfortable or unacceptable. A method called conditioned play audiometry can be used with individuals who are unable to respond to sounds in the usual way (e.g., raising a hand or pressing a button). The person responds to sounds by performing a "preferred activity" (e.g., making a move in a board game or inserting a piece in a puzzle). The audiologist can also use lights and age-appropriate objects to reinforce correct responses.
If this approach is unsuccessful, behavioral observation audiometry is another option. The person is observed for behavioral responses (e.g., eyes widening, vocalization, looking around to sounds). When conducting behavioral observation audiometry, it is important to have someone present who knows the person being tested quite well (e.g., family member, friend, staff person) to help the audiologist distinguish behaviors that are responses to the sounds from those that are part of his or her usual pattern.
Evaluation of hearing is only part of the audiologist's responsibility. He or she will also determine if there is blockage in the outer ear (ear canal, eardrum) and the middle ear. A test that does not need active cooperation is called impedance or tympanometry. With this test, varying degrees of sound and pressure are sent to the ear through a small plug placed in the ear canal. This measures how much sound goes through to the middle ear and how much sound bounces back off the eardrum. This is important to find ear conditions that may need medical attention. This test is better suited for the person with limited communication skills.
There are other tests for people who do not give consistent responses to those tests described above. While these tests can not indicate how much sound a person is processing, they can help determine how well or poorly the auditory system is working. However, no one test should stand alone in determining the level and type of hearing loss in people with developmental disabilities. A comprehensive audiological evaluation for someone with severe developmental disabilities will use a group of tests to determine the nature and extent of hearing loss.
What is a Hearing Evaluation?
A hearing evaluation is a good opportunity to obtain important information about an individual's hearing. This information will be easier to remember if you take notes. You can obtain the information that is needed to support an older adult with a hearing loss by asking the hearing care specialist the following questions:
How Often Should Hearing be Tested?
The National Institutes of Health recommend that hearing is screened every year after the age of 65, but do not wait this long. Any time you suspect the possibility of a hearing loss, a test should be performed by an audiologist. People with Down syndrome, who may experience hearing losses earlier in life, should have periodic hearing tests throughout their life.
What Can be Done to Cope With a Hearing Loss?
The best way to cope with a hearing loss is to: a) admit to a hearing problem; b) explain the problem to other people; and, c) suggest ways to improve the communication environment with others. Some people who have developmental disabilities may not be able to explain their hearing problem or suggest ways to improve communication with other people. These people may need to rely on others to help them arrange their environment and use good communication strategies. Effective communication strategies include:
Individuals using hearing aids and people with developmental disabilities typically require training to learn how to recognize different sounds and signals (e.g., fire alarm, car horn) and to know what they mean.
How Do Hearing Aids Help?
In some ways, having a hearing loss is similar to having a visual impairment. For many individuals who wear glasses, their poor eyesight is corrected. However, for others the nerves in the eye or the brain may be damaged; for them wearing glasses does not eliminate the problem but may help somewhat to lessen its severity. Similarly, some people with hearing loss may find that a well-fit hearing aid seems to correct their hearing problem. Others may receive help from a hearing aid although normal hearing is not restored. Most hearing aid users are in this latter group. As the name implies, a hearing aid should be considered an aid and not a cure for a hearing loss. Speech that is amplified by a hearing aid may sound very different from that which the person with a hearing impairment may be accustomed. Given time and audiologic rehabilitation training, the person with a new hearing aid should find that communicative situations become easier with the aid than without it. Practice is a key element for successful hearing aid use.
More modifications are possible with hearing aids than ever before. If problems arise, consult a hearing care specialist for additional assistance. This professional support, along with motivation of the user and encouragement from family and friends will be critical for attaining improved listening with the device.
Are Hearing Aids the Only Option for a Person With a Hearing Loss?
In addition to hearing aids, assistive listening devices can also be used to overcome the negative effects of noise or distance from speakers. These devices can be used with or without hearing aids to improve telephone, TV, and radio listening, as well as general communication. Most people will find that they get greater benefit from devices used with a hearing aid set to compensate for their hearing loss. These devices include personal FM systems, hardwire systems, induction loop systems and infrared systems.
What if the Person Also Has a Vision Loss?
A vision loss can make the functional effects of any hearing loss more severe. Because vision and hearing work together, much of what we see helps us understand what we hear. It is important to test both vision and hearing at least annually. People who have both hearing and vision losses may lose the ability to interact with the environment. People may be frightened by a sudden touch because they did not know another person was nearby. Hearing aids may be useful for increasing awareness of the environment. In this situation, amplifying the sound of footsteps so they can be heard will indicate the presence of someone who cannot be seen.