The cause of your hearing loss is individual to your situation. There are multiple issues that produce impaired hearing sensitivity. Sometimes those causes are easily determined, while others are based on presumption and may remain vague and indistinct. Predominantly, hearing impairment is caused by the following (in no particular order): aging, middle ear infections, excessive noise exposure, head trauma, ear injury, congenital defects, genetic disorders, or pharmaceutical means (ototoxic medications or treatments).
There are three main types of impairment: conductive, sensorineural, and mixed loss.
Each type of loss has multiple causes.
Conductive impairment is due to disorder, dysfunction, or malformation of the outer ear, middle ear, or combination of the two. Congenital malformations of the external ear causing a lack of full formation of the auricle/pinna and/or ear canal may cause this type of impairment. read more about this topic.
Perforations or holes in the ear drum from disease or trauma are also known causes. Very commonly, middle ear infections (otitis media) cause conductive impairments. Impaired or broken connections of the middle ear bones due to trauma will also cause a conductive loss of hearing. Most conductive impairments can be treated medically and improved upon.
Sensorineural impairment is due to disorder, dysfunction, lesion, or malformation of the inner ear or auditory nerve, or a combination of the two. Congenital and genetic disorders may cause a sensorineural hearing loss. Maternal infections during pregnancy (e.g., herpes, toxoplasmosis, bacterial infections) may result in sensorineural impairment for the child.
Sensory impairment is often the result of typical aging processes (presbycusis), excessive noise exposure, pharmaceutical intervention (ototoxic medications or treatments), vascular diseases and disorders, and head trauma. Other causes may include kidney disease and acquired infections (e.g., meningitis, labyrinthitis, influenza, and mumps).
Meniere’s disease is a disease of the inner ear, typically presenting dizziness, ringing in the ears (tinnitus), and progressive sensorineural hearing loss as its main symptoms. The loss may be centered only in the area of the auditory nerve. This impairment is often call neural loss or nerve deafness, and is typically due to tumors (e.g., acoustic neuroma) on or near the hearing and balance nerve.
Mixed hearing impairment is a combination of conductive and sensorineural components. Causes may be a mixture of any of the sources of loss from the outer/middle ear and inner ear/auditory (hearing) nerve. Rehabilitation for mixed losses may combine therapies used for both types of hearing loss.