deafness

Definition deafness

deafnesschol: deafness n. a partial or total loss of hearing in one or both ears. Conductive deafness is due to a defect in the conduction of sound from the external ear to the internal ear, most commonly an infection affecting the small bones in the middle ear (*otitis media) but also caused by an abnormal condition of the inner ear (see otosclerosis) that affects the conduction of sound. Perceptive deafness is due to a lesion of the *cochlea in the inner ear, the auditory nerve, or the auditory centres in the brain. It may be present from birth (for example if the mother was affected with German measles during pregnancy). In adults it may be brought on by injury, disease (e.g. *Ménière's disease), or prolonged exposure to loud noises; progressive perceptive deafness (presbyacusis) is common with advancing age. The type of deafness can be diagnosed by various hearing tests (see Rinne's test, Weber's test), and the treatment depends on the cause. See also bearing aid.