Hearing loss in the elderly

• Causes
• Symptoms and signs
• Exams and Tests
• Treatment
• Outlook (Prognosis)
• Possible Complications

Compiled by Dr Bulantrisna Djelantik, Indonesia

"Presbycusis", or age-related hearing loss, is the slow loss of hearing that occurs as people get older. The hearing loss can affect life in many ways. The hearing impaired person may miss out on talks with friends and family. On the telephone, the person may find it hard to hear what the caller is saying.

Sometimes hearing problems can make someone feel embarrassed, upset, and lonely. It's easy to withdraw when they can't follow a conversation at the dinner table or in a restaurant. It's also easy for friends and family to think that someone is confused, uncaring, or difficult, when the problem may be that the person just can't hear well.

If someone has trouble hearing, there is help. The person has to see a doctor or health care provider. Depending on the type and extent of the hearing loss, there are many treatment choices that may help. Hearing loss does not have to get in the way of the ability to enjoy life.

Causes

Inside the inner ear is a small structure called Cochlea, containing rows of hair cells with tiny hairs that help us hear. They pick up sound waves and change them into the nerve signals that the brain interprets as sound. Sensori-neural hearing loss occurs when the tiny hairs inside the ear are damaged or die. The hair cells do not re-grow, so most sensori-neural hearing loss is permanent.

Most commonly, presbycusis is caused by damage to the hair cells that occur as result of aging. Beside the damaged hair cells, there could also be damage in the auditory nerve cells as well as the central auditory processing nerve cells in the brain. However, usually it is a combination with other causes, such as genes and loud noises. Listening to loud music through headphones, or working in very noisy conditions, may play a large role.

The following factors contribute to age-related hearing loss:

• Family history (age-related hearing loss tends to run in families)
• Repeated exposure to loud noises
• Heart and kidney conditions, or stroke
• Smoking (smokers are more likely to have such hearing loss than nonsmokers)

Certain medical conditions and medications also contribute to age-related hearing loss. About half of all people over age 75 have some amount of age-related hearing loss.

Symptoms and signs

Hearing loss may affect the hearing threshold, the volume at which a patient can hear sound, expressed in decibels (dB), discrimination (the ability to differentiate among various speech sounds), or both. The high frequencies of sound, expressed in hertz (Hz) may be affected first.

The loss of hearing affect both ears symmetrically occurs slowly over time. It is most difficult to hear high-frequency sounds, as someone talking. As hearing gets worse, it may become difficult to hear sounds at lower pitches.

Symptoms include:

• Difficulty hearing in noisy areas (also called the "cocktail party syndrome")
• High-pitched sounds such as "s" or "th" are hard to distinguish from one another
• Men's voices are easier to hear than women's.
• Other people's voices sound mumbled or slurred
• Family members may complain that the television is turned n too loud
• Often asks for words to be repeated
• The person avoids social situations, religious services, and movie theaters
• Music lovers may complain that music does not sound as bright
• Certain sounds seem overly loud
• Ringing in the ears

Exams and Tests

A complete physical exam is performed to rule out medical conditions that can cause hearing loss. The health care provider will use an instrument called an "otoscope" to look into the ears. Sometimes, wax can block the ear canals and cause hearing loss.

The patient may be sent to an ear, nose, and throat doctor and a hearing specialist (audiologist). Hearing tests (audiometry, tuning forks test and speech audiometry), can help determine the extent of hearing loss. The typical audiometric test result is a bilateral mild-to-moderate hearing loss. Hearing is usually best in low frequencies and poorest in high.

Patients with central or auditory processing problems, may have a low word recognition score, because their nerve system does not faithfully reproduce the clarity of speech, regardless of loudness. These patients will have difficulty understanding conversational speech without visual cues, despite being able to hear sound with a hearing aid.

Treatment

There is no known cure for age-related hearing loss. Treatment is focused on improving everyday function. The following may be helpful:

1. Hearing aids
   • The types available are body-worn/pocket, behind the ear (BTE), in the ear (ITE), or, in the canal (ITC) types , depending on severity of the hearing loss.
   • However, less than half of elderly people with hearing loss who might benefit from hearing aids actually wear them. Patience and motivation by the hearing aid fitter and family is crucial.
   • Patients should choose a style that they will wear without embarrassment. Cosmetic concerns cannot be ignored in the fitting of hearing aids. The "open fit" BTE for the mild to moderate hearing loss is usually liked because it is convenient to wear and cosmetically almost invisible
   • Patients with symmetric hearing loss usually need binaural hearing aids (in both ears). If patients wear only one hearing aid, they cannot tell where a sound is coming from, and in difficult situations (eg, noisy ones), they cannot hear speech clearly.
   • Of course a monaural hearing aid is used if patient has financial constraints. Sometimes there is binaural interference, thought to result from prolonged deprivation or age-related changes in the central auditory system, which causes marked differences between ears in sound processing and awareness. For people with this relatively rare situation, one hearing aid may actually be better than two hearing aids.
   • Realistic expectations are key to successful treatment with hearing aids. Even the best hearing aids do not enable a patient to hear clearly in adverse listening situations, such as poor acoustics (for instance in rooms with a lot of echoing of sounds), excessive background noise, or poor visual contact between speaker and listener (eg, in poor lighting). Even with well-fitted hearing aids, patients usually need plentiful visual communication cues to maximize speech understanding.
   • A cochlear implant may be recommended for certain people with very severe hearing loss. Surgery is done to place the implant. The implant makes sounds seem louder, but does not restore normal hearing and moreover, it is very expensive.

2. Telephone amplifiers and other assistive devices
   • Hearing aids with a telecoil can be set on "T" to receive (through magnetic induction) the signal from the magnetic coil inside the telephone. While the telecoil is activated, the microphone is usually inactivated; therefore, the background sounds from the room in which the person is speaking is not amplified.
   • Some behind-the-ear hearing aids have direct audio input, allowing the hearing aid to be directly coupled to the telephone (or television, radio, or other media source) with special audio boots and cords.
   • Closed caption provides a written transcription of dialogue and sound effects for many television shows.
   • Infrared systems have a transmitter that sends signals from the sound source (eg, television, radio) to an infrared receiver in a headset worn by people with a hearing loss, who can adjust the loudness of the headset to their comfort level. Infrared receivers are portable and can be used in any public arena that has an infrared transmitter. However, infrared systems are ineffective in direct sunlight (some outdoor arenas), and they do not work if light transmission to the receiver is physically blocked.
   • FM systems have a microphone at the sound source that sends signals to a transmitter, which broadcasts the signal via FM radio waves to a receiver worn by people with a hearing loss. FM systems are portable, can be used indoors and outdoors, and can be used by people with a wide range of hearing losses. FM systems with attenuated headsets are being increasingly used by people with normal hearing and central auditory processing disorders.
   • Alerting systems may be used to replace sounds in the home and community (eg, telephone, doorbell, door knock, alarm clock, smoke and carbon monoxide detectors, home security systems, sirens). Most devices use a visual signal (eg, light) to represent the sound. For example, a device hooked up to the doorbell can set off a flashing light in the kitchen.
   • Ordinary means of communication such as mobile phones, portable pagers and e-mail enable people with a hearing loss to easily, accurately, and instantly communicate with others.
3. Speech reading (such as lip reading and using visual cues to aid communication)
   • Other people can help the person with presbycusis a lot by simply speaking clearly: the speaker should pronounce each syllable carefully and clearly but without undue exaggeration.
4. Sign language (for those with severe hearing loss)

Outlook (Prognosis)

Age-related hearing loss is progressive, which means it slowly gets worse. The hearing loss is permanent.

Possible Complications

Hearing loss can result in both physical (not hearing a fire alarm) and psychological (social isolation) problems. In the long term, the hearing loss may lead to deafness (profound hearing loss).