Hearing loss at any age can be caused by: measles, mumps and chickenpox, especially if accompanied by a high fever; bacterial meningitis; Lyme disease; aplastic anemia; multiple sclerosis; vascular disease.
Premature babies (weighing less than 1500 g / 3.3 lbs), especially those who have been on ventilation for five days or more, may be at increased risk.
Hyperbilirubinemia (excess bilirubin, the blood chemical which is normally broken down by the liver) requiring transfusion may also result in hearing loss.
Injury or noise
A blow to the head or exposure to excessive noise can damage the internal structure of the ear.
Aminoglycosides such as gentamycin (either in multiple courses or in combination with loop diuretics) as well as other antibiotics such as vancomycin and streptomycin.
Calcium channel blockers.
Oral contraceptives and HRT.
Anesthetics such as that used in epidurals.
Chemotherapy such as Cisplatin or Carboplatin (platinum).
Labyrinthotomy (surgery to correct vertigo).
Hearing can be damaged as the result of disease toxoplasmosis, rubella, syphilis, cytomegalovirus or herpes contracted by the mother before birth.
Inherited characteristics can make one susceptible to disease and defects to the ear and hearing system.
Hearing may occasionally diminish as a natural part of ageing.