There are 2 basic types of hearing loss, which are called conductive and sensorineural.
Conductive causes: Conductive hearing losses result from physical problems with the movement of the sound wave through the ear. A simple example is blockage of the ear canal.
Obstructed external ear canal - Cerumen (wax) build-up, hematoma(blood collection), or foreign body in the ear canal. This is one of the most common causes of hearing loss and the easiest to fix.
Perforated tympanic membrane - Caused by direct trauma such as a finger or cotton swab, middle-ear infections (otitis media), or explosions (blast injury)
Dislocated ossicle (malleus, incus, or stapes) - Usually from trauma to the ear
Otitis externa - Infection of the ear canal that causes it to swell
Sensorineural causes: Sensorineural causes are from damage to the hair cells or nerves that sense sound waves.
Acoustic trauma - Prolonged exposure to loud noises causes the hair cells on the cochlea to become less sensitive.
Barotrauma (pressure trauma) or ear squeeze - Usually in divers
Head trauma - A fracture of the temporal bone can disrupt the nerves of the auditory system
Ototoxic drugs - Certain drugs can affect hearing by damaging the nerves involved in hearing. Usually this occurs when large or toxic doses are used but may also occur with lower doses.
Antibiotics including aminoglycosides (gentamicin, vancomycin), erythromycins, and minocycline
