Pathophysiology - Hearing Impairment

HEARING IMPAIRMENT

Hearing Impairment – described as mild, moderate, severe, or profound depending on the intensity of sound required for a person to hear it

Results from

• Conducting hearing loss – mechanical problem in the external ear canal or middle ear that blocks the conduction of sound
• Sensorineural hearing loss – damage to the sensory structures (hair cells) of the inner ear, auditory nerve pathways in the brain

Causes

• Sensorineural hearing loss
• aging- prebycusis
• Conductive hearing loss
• Choleastoma – non cancerous tumor caused by ear infection
• Chronic middle ear fluid – otitis media with effusion
• Middle ear infection – otitis media
• Obstruction of External ear canal – obstruction is caused either by a wax, tumor or pus from an infection
• Otosclerosis – bony growth of the ossicles

Prevention

• Age related hearing loss and most other causes of hearing loss are not preventable
• Noised induced hearing loss – can be prevented by
• Limiting exposure to loud noise
• The volume through headphones should always be kept at a reasonable level
• Use of glycerin filled muffs or ear plugs – for occupational and firearm exposure

Treatment

• Depends on the cause
• Fluid in the middle ear - tympanostomy (tube placed in the eardrum to prevent fluid from accumulating
• Hearing loss caused by autoimmune disorders – treated with corticosteroids
• Damage to the eardrums or the bones in the middle ear – may require reconstructive surgery
• Brain tumors causing hearing loss may, in some cases, be removed and the hearing preserved
• Most other causes of hearing loss have no cure
• Those with severe to profound hearing loss are greatly helped by a cochlear implant
• Hearing aids
• helps people who have either conductive or sensorineural hearing loss through amplification
• does not restore hearing to normal
• significantly improve a person’s ability to communicate and enjoy sounds