Hearing Loss
Hearing loss may be conductive, where there is impairment of transmission of sound from the outside to the inner ear, or perceptive, or sensorineural, where there is impairment of transmission of the electrical impulses down the nerve from the ear to the brain. By far the commonest cause of mild hearing loss in children is middle ear disease due either to infection or the presence of fluid (see glue ear in this section). This produces a conductive deafness which is treatable. If it is chronic, it may interfere with the child’s development (if you can’t hear, you don’t learn) and any child who is failing to progress should have their hearing tested. More rarely the hearing loss is due to malfunction in the nerve from the ear, or in the central brain cells - a sensorineural deafness which is untreatable. It ranges in severity from mild to profound, when communication depends on sign language. There are rare genetic causes, but most result from congenital problems such as viral infections before birth (cytomegalovirus, German measles) or birth problems involving lack of oxygen during delivery. In the older child it can be a consequence of bacterial meningitis.
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