Patients with hearing loss should be investigated. The common causes of hearing loss are:

• Ear wax impaction
• Foreign body in the ear
• Ear canal narrowing (developmental abnormality or a result of repeated ear canal trauma)

• Ear drum hole
• Middle ear infection
• Fluid in the middle ear, usually caused by nasal infection
• Abnormal middle ear bone (ossicles)
• Barotrauma (middle ear pressure induced hearing loss)

• Age-related hearing nerve degeneration
• Hearing nerve degeneration from exposure to excessive loud noise
• Drug-induced hearing nerve degeneration
• Hearing loss from viral infection
• Birth related hearing loss
• Hearing nerve damage from previous head injury