Deafness

Alternative names

Decreased hearing; Hearing loss; Loss of hearing

Definition

Hearing loss is the total or partial inability to hear sound in one or both ears.

Considerations

Preventing hearing loss is more effective than treating it after "the damage is done."

Minor decreases in hearing are normal after age 20. Some deafness related to nerve damage affects 1 out of 5 people by age 55. It usually comes on gradually, and it rarely ends in complete deafness. See hearing loss of aging. Alzheimer's disease or other neurological problems may sometimes be falsely suspected in older people because they have hearing problems.

There are many causes of hearing loss. They can be divided into 2 categories:

• Conductive loss occurs because of some mechanical problem, such as fluid in the ear. The three tiny bones of the ear (ossicles) may fail to conduct sound to the cochlea or the eardrum may fail to vibrate in response to sound.
  
• Nerve loss occurs when the nerve is injured by physical or other means.
  

Conductive loss is often reversible - nerve loss is not.

Screening for hearing loss is now recommended for all newborns. In children, hearing problems may cause speech to develop slowly.

Ear infections are the most common cause of temporary hearing loss in children. Fluid can linger in the ear following an ear infection. Although this fluid can go unnoticed, it can cause significant hearing problems in children. Any fluid that lasts longer than 8-12 weeks is cause for concern.

Common Causes

Genetic:

• Osteogenesis imperfecta
  
• Leopard syndrome (multiple lentigines)
  
• Otosclerosis
  
• Robinson type ectodermal dysplasia
  
• Cockayne syndrome
  
• Bjorn pili torti and deafness syndrome
  
• Multiple synostosis syndrome
  
• Hunter syndrome
  
• Taybi oto-palato-digital syndrome
  
• Hereditary nephritis
  
• Mohr syndrome
  
• Hurler syndrome
  
• Waardenburg syndrome
  
• Kartagener syndrome
  
• Fronto-metaphyseal dysplasia syndrome
  
• Morquio syndrome