Hearing loss can be categorized by many different types. Two types of hearing loss are sensorineural and conductive. Both types of hearing loss can be congenital (present at birth) or acquired.
Sensorineural. A loss of function within the inner ear or with the connection to the brain. Causes of this type of hearing loss include:
Congenital factors (conditions present at birth) such as:
Infection by the mother with toxoplasmosis, rubella, cytomegalovirus, herpes, or syphilis
Maternal diabetes
Complications associated with Rh factor in the blood
Genetic factors and syndromes the child has at birth
Low birthweight or prematurity
Hereditary (in the family)
Acquired
Loud noise exposure
Trauma
Infections
Damage from certain medications that can be harmful to the ears
Conductive hearing loss. A problem in the outer or middle ear where sound waves are not sent to the inner ear correctly. Conductive hearing loss is the most common type of hearing loss in children and is usually acquired. Factors that may cause this type of hearing loss are:
Congenital factors (conditions present at birth) such as:
Anomalies of the pinna (the outside of the ear)
Anomalies of the tympanic membrane (eardrum)
Anomalies of the external ear canal
Anomalies of the ossicles (the three tiny bones that deliver the sound waves to the middle ear)
Acquired
Excessive wax
Foreign bodies in the ear canal, such as beads or popcorn kernels
Tumors of the middle ear
Problems with the eustachian tube
Ear infections such as otitis media
Chronic ear infections with fluid in the middle ear
Perforation of the eardrum
