The sounds of nature, the voices of loved ones, the information from radio and television - these all affect the way people connect to their world. Deafness, a silent disability, can affect every aspect of a person's life. It is both frightening and saddening to live in a world that is becoming garbled and silent. Hearing loss can threaten a person's independence and enjoyment of life.
Sounds are moving waves of air. Sound waves come in many sizes and lengths. These differences are what we hear as different sounds. First, the outer ear collect the sound waves - so the larger the ears, the better the hearing. This principle works well for the rabbit.
The waves then beat against the ear drum with their particular rhythm and strength and cause vibration within the middle ear. These vibrations move along a chain of three small bones to reach the inner ear. In the inner ear, the vibrations are changed into nerve signals that are sent to the brain for interpretation.
Things can wrong at any point in this process. Sound waves may not reach the ear drum if there has been a disease or accident in the outer ear or when ear wax plugs the outer ear. The ear drum may be damaged by infection or injury. The chain of bones may be damaged or inefficient due to infections, accidents or even an inherited condition where they become rigid. In the inner ear, damage can occur that affects the transmission to the brain of high frequency sounds (treble), low frequency sounds (bass), or both.
The interpretation of signals in the brain can be damaged after accidents, inflammations or strokes. Rarely, a growth on the hearing nerve (the transmission cable) can affect the sending of the signals.
Loud noise can damage hearing sooner or later. This hearing loss may be linked to the amount of loud noise that a person is exposed to over a lifetime. In fact, the level and strength of sounds to which a person is exposed are more important in causing deafness than any aspect of aging itself.
Typically, the high frequency sounds are the most affected by loud noise but this may progress until all sounds are difficult to hear. Unfortunately, the human voice is in these higher frequencies. Deafness is usually called 'conductive' if its cause is in the outer or middle ear apparatus itself. It is called 'sensori-neural' if the problem is along the nerve pathways from the inner ear to the brain.
Deafness doesn't just mean that sounds are not loud enough to hear; it often involves problems with recognizing individual sounds. People are bombarded with sound waves all the time. Those with normal hearing can tell the difference between a baby crying, a tap dripping, and a car starting - even if they occur at the same time. There may be four or five people talking at a party but it is possible to "tune in" on specific conversations.
This is discrimination - the ability for the hearing system to separate sounds even if they all arrive at the ear at the same time. A deaf person is not able to discriminate sounds so clearly. This is why a deaf person has more difficulty hearing in crowds than speaking one on one in a quiet place.
The first step toward help is an adequate assessment by the family doctor. If the problem is conductive, it can often be cured. If there is no obvious problem when the ear is examined, the next step is usually an audiogram.
An audiogram tests each ear for its ability to hear different types of sound at different strengths. Speech discrimination is tested separately from the standard audiogram and must be performed at the same time to measure the overall hearing loss.
The main need of a deaf person is to be able to communicate and to remain connected with the world. There are several ways of improving communication.
A hearing aid can be helpful but it has to be correct for that person. The type and complexity of the aid will depend on the underlying reason for the deafness and its severity. For the most part, hearing aids make sounds louder but may not improve discrimination. Miniaturization and computerization make it possible to conceal hearing aids in eyeglass frames or even inside the ear itself.
Anyone with a hearing loss has a right to ask people for help. This may mean asking people to change the way they speak to the hearing-impaired person; to speak up, speak slowly, or speak while looking directly at the person.
There are items for use in the home to improve communications. An amplified telephone is a good example. Another is the option of 'closed captions' on television. This allows a person to be part of a common activity along with family or friends who are not hearing-impaired.
Most older people with deafness can be helped. If you are having trouble hearing the normal sounds around you, talk to your doctor. You owe it to yourself to hear, communicate and remain connected to the richness of life.