Many people associate hearing loss with old age but there are many other causes of hearing loss. These include: hereditary, pathological (result of disease) and those of unknown origin, also referred to as idiopathic.
Hearing loss is usually described as one of two categories: conductive or sensorineural, depending on where the hearing loss originates in the ear. It is also possible to have a mixed loss which is a combination of the two. Knowing the type of hearing loss is necessary to determining the proper course of treatment.
Conductive Hearing Loss
Conductive hearing loss occurs when sound is not conducted optimally through the outer or middle ear. Its origin may involve the outer ear, ear canal, eardrum, middle ear bones or space, or any combination of these. A conductive loss usually results in a mild to moderate hearing loss which may affect all frequencies relatively uniformly or be especially pronounced in the low-frequency range. Most conductive hearing losses can be treated medically or surgically. It is also possible for a conductive loss to be longstanding or permanent but these losses can often be helped with hearing aids.
There are a number of conditions that may cause conductive hearing loss:
- Middle ear infection
- Perforation of the eardrum
- Deformity of the outer ear
Children and Conductive Hearing Losses
Some of the most common causes of conductive hearing loss in children are accumulation of earwax (cerumen) or other debris in the ear canal; and, middle ear infection (otitis media). Either can lead to a considerable hearing loss.
Earwax or other debris should be removed by the medical or health professional. Without complication, hearing is typically fully restored.
Middle ear infection is very common in young children. An acute infection can be very painful and treatment should be sought immediately. Infection of the middle ear is an infection of the mucous membrane in the middle ear. The infection can be caused by bacteria or virus and is nearly always a consequence of an infection in the nose or throat, for example in connection with a cold, the flu, children's diseases or sinusitis. Young children are particularly vulnerable to infection of the middle ear because the pathway from the back of the throat to the middle ear (the Eustachian tube) is short and angled, allowing bacteria to easily reach the middle ear.
In some cases the infection can result in perforation of the eardrum because fluid build-up presses the eardrum outwards until it bursts. A healthy eardrum usually heals by itself by developing scar tissue that closes the perforation. After many episodes of middle ear infection so much scar tissue may have formed that it results in a conductive hearing loss. Chronic infection could lead to a considerable conductive hearing loss, and possibly result in severe complications such as dizziness and/or sensorineural hearing loss.
Today there is greater awareness about the detrimental effects that conductive hearing loss can have on a child's speech, language and learning. This has often resulted in more aggressive medical treatment as well as hearing habilitative measures including hearing aids in the case of chronic conductive problems
Sensorineural Hearing Loss
Sensorineural hearing loss occurs when the cochlea (inner ear), neural fibers or their connections to the cochlea are damaged or do not function optimally as related to either lack of normal development or disease. A sensorineural loss may range from a mild to a profound hearing loss which may affect all or some of the frequencies. Sensorineural hearing loss cannot be treated medically or surgically. However, those with sensorineural losses can benefit from hearing aid usage.
There are a number of conditions that result in sensorineural hearing loss:
Heredity and congenital conditions
- Acute illnesses
- Acoustic trauma
- Reactions to ototoxic medications
Children and Sensorineural Hearing Loss
The most common causes of sensorineural hearing loss in children are: congenital conditions, systemic infections due to acute illnesses, and acoustic trauma.
Congenital hearing loss implies that your child was born with the loss. It may be hereditary, stemming from a known or unknown family history. Congenital hearing losses may be a consequence of genetic syndromes, e.g. Down's syndrome. Furthermore, these types of hearing loss can arise from factors affecting pregnancy such as alcohol, drugs or medications taken during pregnancy, illnesses contracted by the mother before or during pregnancy or complications during labor.
Severe cases of certain infections such as measles, mumps, meningitis or whooping cough can lead to various degrees of sensorineural hearing loss. Continual exposure to excessive loud sounds or a brief exposure to sudden impact sounds can cause sensorineural hearing loss, e.g. fireworks and cap guns.
Adults who experience sensorineural hearing loss are unfortunately sometimes reluctant to pursue the necessary help from hearing aids they may need for better hearing and communication function. In the case of children, early identification and treatment is imperative to minimize the chance of delayed developmental milestones and possible academic difficulties. Children identified with hearing loss as early as infancy can be fit with hearing aids and develop appropriate skills with the proper support and learning environment..