Sensorineural hearing loss is defined as a loss of hearing caused by problems occurring in the inner ear and auditory (hearing) nerve. Causes may include aging, genetic-associated loss (hereditary), noise exposure or noise trauma, infections, congenital syndromes, inflammatory or auto-immune diseases, among others. Sudden sensorineural hearing loss describes hearing loss occurring over a less than three day period. Chronic sensorineural hearing loss may be observed with periodic hearing tests if mild, hearing aids for those with more significant loss, and cochlear implantation for those with profound loss (deafness). Sudden hearing loss may be treated with steroids, either given orally or injected into the middle ear.
Conductive hearing loss of the middle ear is a type of hearing loss caused by a problem preventing sound waves from conducting from the eardrum to the inner ear. This may be caused by fluid in the middle ear, scarring of the middle ear, or problems with the ossicles (hearing bones of the middle ear), such as a dislocation of an ossicle, congenital malformation of one or more ossicles, or, most commonly otosclerosis. Otosclerosis is a disorder of the bone around the stapes, the third of the ossicles - the hearing bones of the middle ear. The bone around the base of the stapes becomes hardened and fixed, preventing the normal motion of the stapes in response to sound waves, resulting in a conductive hearing loss. Treatment options include fluoride treatment to slow the change in the bone, hearing aids, or surgery to loosen the bone or place a prosthetic bone. Dislocation of an ossicle, or other problems with the other ossicles may be treated with repositioning of the bones or with placement of a prosthetic bone. Middle ear fluid may either resolve on its own with time, or be treated surgically with a myringotomy (drainage of the fluid through the eardrum).
