Hearing loss is categorized by what part of the auditory system is affected. The four basic types of hearing loss are conductive hearing loss, sensorineural hearing loss, mixed hearing loss and central auditory processing disorders.

Conductive Hearing Loss

Conductive hearing loss occurs when sound does not move efficiently through the outer or middle ear systems. The presence of a foreign bodies, impacted cerumen (ear wax) and fluid in the middle ear from colds, allergies or ear infections can all cause conductive hearing loss. In addition, disorders or malformation of the pinna, ear canal or ossicles (tiny bones in the middle ear) can cause this type of loss. Conductive hearing loss can often be corrected with medicine or surgery.

Sensorineural Hearing Loss

Sensorineural hearing loss results from damage to the cochlea (inner ear) or to the auditory nerve that runs from the cochlea to the brain. Certain diseases, injuries, ototoxic drugs and genetic syndromes can cause sensorineural hear loss. It can also occur as a result of noise exposure, viruses, head trauma, aging and tumors. Usually, sensorineural hearing loss is permanent and cannot be medically or surgically corrected.

Mixed Hearing Loss

Mixed hearing loss occurs when there is damage to both the outer/middle ear systems and the inner ear or auditory nerve resulting in a combination of sensorineural and conductive hearing loss.

Central Auditory Processing Disorders

Central auditory processing disorders (CAPD) occur when the parts of the brain that interpret sound are affected by injury, disease, tumor or other unknown causes. Central auditory processing disorders may result in a diminished ability to localize sound, discriminate and recognize auditory patterns, utilize temporal aspects of sound, or deal with degraded or competing acoustic signals.