Etiologic causes of hearing loss can be categorized into three groups: (1) Sensorineural, (2) Conductive, and (3) Sensorineural and Conducitve.
Sensorineural hearing loss results from problems with the vestibulocochlear nerve (cranial nerve VIII), inner ear, or central processing centers of the brain.
When performing the Weber Test on patients with sensorineural hearing loss (tuning fork touched to midline of skull), sound localizes to the normal ear (i.e. sound conducts normally through bone, which measures sensorineural function, on the side without the abnormality).
Examples of conditions that cause sensorineural hearing loss include: Acoustic neuroma and other cerebellopontine angle tumors, perilymph fistula, noise trauma, and ototoxic medications.
