Hearing and Deafness - Prevention and Treatment 

Age-related hearing  loss and many other causes  of hearing loss are not preventable. However, many measures  can be taken to help prevent noise-induced hearing loss, such as limiting exposure to loud noise, reducing noise levels whenever possible,  and staying away from the source  of the noise. The volume of music played through headphones should always be kept at a reasonable  level. The louder the noise, the less time a person should spend near it. For occupational  or firearm exposure, the use  of hearing protectors, such as  plastic or foam rubber plugs in the ear canals or glycerin-filled muffs over the ears, is essential. Plastic plugs can  also be used in other loud environments. 

Treatment of hearing loss depends on the cause. When the cause is obstruction of the canal from debris or wax, a doctor  can vacuum (wash) the canal or recommend over-the-counter drops that dissolve ear wax. When the cause is fluid in the middle ear, children and adults may need to have a small tube placed in the eardrum (tympanostomy (see Ear, Nose, and Throat Disorders:Middle Ear Infections ). The tube helps prevent fluid  from accumulating. Some children also need to have their adenoids removed (adenoidectomy), which helps keep the eustachian tubes open. Hearing loss caused by autoimmune disorders and sudden hearing loss are treated with corticosteroids, such as prednisone. 

Damage to the eardrums or the bones in the middle ear may require reconstructive surgery. For some people with otosclerosis, hearing may be restored by removing the stirrup surgically and replacing it with an artificial one. Brain tumors causing hearing loss may, in some cases, be removed and the hearing preserved. 

Most other causes of  hearing loss have no cure. In these cases, treatment involves compensating for the hearing loss as much as possible. Most people with moderate to severe loss use hearing aids. Those with severe to profound loss are greatly helped by a cochlear implant. 

Hearing Aids: Sound amplification with a  hearing aid helps people who have either conductive or sensorineural hearing loss. Unfortunately,  a hearing aid does not restore hearing to normal. A hearing aid should, however, significantly improve a person's ability to communicate and enjoy sounds. 

Many people are reluctant to wear hearing aids because  of social stigma. Doctors should discuss such issues and encourage people to meet with an audiologist to evaluate the array  of different hearing aid designs available. Some older people and those with arthritis or neurologic problems find it difficult to manipulate the smallest  hearing aids and should consider slightly larger devices. 

All hearing aids have a microphone to pick up sounds, a battery-powered amplifier to increase their volume, and a  means of transmitting the sound to the person. Most hearing aids transmit the sounds through a small speaker placed  in the ear canal. Other hearing aids, which require surgical implantation, transmit sounds directly to the bones of the middle ear (ossicles) or the skull instead of through  a speaker. Hearing aids differ in how big the components are and where they are located. As a general rule, larger hearing aids are more noticeable and less attractive but are easier  to adjust. Larger hearing aids can often accommodate features that are not available in small ones. 

Hearing aids have different electronic characteristics that are chosen  to suit the person's particular type of  hearing loss. For example, people whose hearing loss affects mainly higher frequencies do not benefit from simple amplification, which merely makes the mumbled speech they hear sound louder. Hearing aids that selectively amplify the high frequencies markedly improve speech recognition. Other hearing aids contain vents in the ear mold, which facilitate the passage of high-frequency sound waves into the ear. Many hearing aids use digital sound processing with multiple frequency channels so that the amplification can even more precisely match the person's hearing loss. People who cannot tolerate loud sounds may need hearing aids with special electronic circuitry, which keeps the maximum volume of sound at a tolerable level. 

Telephone use can be difficult for people with hearing aids. With typical hearing aids, placing the ear next to the phone handle causes squealing. Some hearing aids have a phone coil: With the flip of a switch the microphone is turned off, and the phone coil links electromagnetically to the magnet in the phone handle. As long as the hearing aid has the proper features, this setup can be arranged by the phone company with simple changes to the phone. Hearing aids with complex features tend to be the most expensive but are often essential to meet hearing needs. 

Cochlear Implants: Most profoundly deaf people who cannot hear sounds even with a hearing aid benefit from a cochlear implant. Cochlear implants provide electrical signals directly into the auditory nerve by means of multiple electrodes inserted into the cochlea, which is the inner ear structure containing the auditory nerve. An external microphone and processor pick up sound signals and convert them to electrical impulses. The impulses are transmitted electromagnetically by an external coil through the skin to an internal coil, which connects to the electrodes. The electrodes stimulate the auditory nerve. 

A cochlear implant does not transmit sounds  as well as  a normal cochlea but does provide substantial benefit to the hearing impaired. It helps people read lips. Most implantees can distinguish words without reading lips  and also use the telephone. 

A cochlear implant also helps deaf people hear and distinguish environmental and warning signals, such as doorbells, telephones, and alarms. It helps them modulate their own voices  to make their speech easier  for others to understand. A cochlear implant is more effective in a person whose hearing loss is recent or who has successfully used a hearing aid before the implant. 

Other Means  of Coping With Hearing Loss: Several types of assistive devices are available for people who have significant  hearing loss. Light alerting systems enable people to know when the doorbell is ringing  or a baby is crying. Special sound systems help people hear in theaters, churches, or other places where there is competing noise. Many television programs carry closed captioning, with  the dialog shown as visible text. Telephone communication devices are also available. 

Lip reading (speech reading) is an important skill for people who have decreased hearing. It is particularly important for people who  can hear but have trouble discriminating sounds, typically those with age-related hearing loss. Observing  the position of a speaker's lips allows people to recognize which consonant is being spoken. Because people whose hearing loss affects high frequencies are unable to understand consonant sounds, lip reading can significantly improve the comprehension of speech. 

Lip reading and other strategies for coping with hearing loss are sometimes taught by hearing professionals in a program called aural rehabilitation. In addition to training in lip reading, people are taught to gain control over their  listening environment by learning  to anticipate difficult communication situations and modifying or avoiding them. For example, people  can visit a restaurant during off-peak hours, when it is quieter. They can ask for a booth, which blocks out some extraneous sounds. They can request that "specials of the day" be written rather than spoken. In direct conversations, people may ask the speaker  to face them. At the beginning of a telephone conversation, people can identify themselves as being hearing-impaired. 

People with profound hearing loss often communicate using sign language. American Sign Language (ASL) is the version most widely used in the United States. Other forms include Signed English, Signing Exact English, and Cued Speech.