A B C D E F G H I J K L M N O P R S T U V W

DEAFNESS

What is Deafness ?

Deafness is the loss of ability to hear normally. There are two types of deafness conductive and sensori-neural. These may occur separately or together and one (unilateral) or both ears (bilateral) may be involved. All degrees of hearing loss, from slight to total, may occur. Conductive deafness is due to interference with the conduction of sound across the middle ear to the inner ear. Sensori-neural deafness is due to reduced function of the inner ear (cochlea) or the nerve fibres leading to the brain.

How does Deafness occur ?

Deafness caused during pregnancy or at birth is called congenital deafness. Defects as the foetus develops sometimes produce congenital conductive deafness. Most cases of deafness at birth are sensori-neural and are due to German measles (rubella) affecting the mother in early pregnancy. Rubella may also cause other defects in the baby apart from deafness. Less frequently, other infections or complications of pregnancy and birth may cause deafness. Acquired deafness in children is most often due to fluid forming in the middle ear. This condition can be successfully treated and is due to poor function of the Eustachian tube, a channel which connects the middle ear to the back of the nose. The commonest cause of deafness in adults is called presbycusis. It is due to degeneration of the cochlea (inner ear) as part of the ageing process. There are many other causes of acquired deafness and these include wax, injury, infections, rare tumours, some drugs and Meni re's disease.

Why does Deafness occur ?

Rubella deafness occurs either because the mother has not been immunized or has not previously had German measles. If the mother develops rubella in early pregnancy, there is a high risk of deafness occurring in the baby. Aging may contribute to the high frequency tone loss of presbycusis. Very loud noise in industry or from hobbies, such as pop music or shooting, may also cause a high tone loss (acoustic trauma). The ears should be protected by defenders when there is exposure to very loud noise over prolonged periods. The trauma of head injury often from accidents can cause both types of deafness.

Treatment Involved for Deafness

The doctor may want to remove wax from your ears to see if this benefits hearing. If there is no improvement, a referral to a specialist may be considered. The specialist will take a history and carry out an examination. A hearing test and other tests, including blood examination and x-ray or magnetic scans may be carried out. It may be necessary to have repeated hearing tests. Depending on the results and the type of deafness diagnosed, different treatments may be suggested. For most patients with sensori-neural deafness the main treatment is the provision of a hearing aid. Hearing levels are measured in decibels. If hearing level is say, 30 decibels (30 dB), then 30% of hearing may have been lost. At this level quiet conversation will be missed. If the hearing loss is at 30 decibels or greater, then the use of a hearing aid is usually considered. Modern hearing aids are much lighter and smaller and better than those of years ago. They can be worn behind your ear and easily covered by the hair. Even smaller aids can be purchased to wear in the ear. All hearing aids consist of a microphone, an amplifier and a receiver. The microphone picks up the sound, the amplifier makes it louder and the receiver is a small loudspeaker. Sometimes, making sounds louder does not help the patient understand better. This is because the ear has lost the ability to discriminate what the sounds mean. The latest digital aids may be better for some patients, but others may do well with a more traditional type of aid.

During Treatment for Deafness

Depending on the cause, some cases of deafness may respond to treatment with drugs, including antibiotics. The medicines must be taken as instructed and side-effects watched for. If a hearing aid has been prescribed, one should be aware how to use it and how to look after it. The hearing aid dispenser should be asked about other aids for the hard of hearing. Various devices are available, including loop systems and plug-in aids to the television. Amplifiers and warning lights may also be used in telephones. If deafness is progressive or severe, lip reading classes may prove essential.

If Deafness is Left Untreated

Deafness in children interferes with the social and educational development of the child. It may be mistaken for backwardness. All young children must be screened to avoid these problems. Delayed speech and problems with behaviour are common in deaf children. Adults who become deaf may not be able to do their jobs properly and they may have social problems. They may annoy their neighbours with radios, TV sets and hi-fi sets which are too loud. Many of these problems may be helped by using aids.