The causes of hearing loss and deafness can be divided into congenital causes and acquired causes.
- Congenital causes may lead to hearing loss being present at or acquired soon after birth. Hearing loss can be caused by hereditary and non-hereditary genetic factors or by certain complications during pregnancy and childbirth, including:
- Maternal rubella, syphilis or certain other infections during pregnancy;
- Low birth weight;
- Birth asphyxia (a lack of oxygen at the time of birth);
- Inappropriate use of particular drugs during pregnancy, such as aminoglycosides, cytotoxic drugs, antimalarial drugs, and diuretics;
- Severe jaundice in the neonatal period, which can damage the hearing nerve in a newborn infant.
- Acquired causes may lead to hearing loss at any age, such as:
- Infectious diseases including meningitis, measles and mumps;
- Chronic ear infections;
- Collection of fluid in the ear (otitis media);
- Use of certain medicines, such as those used in the treatment of neonatal infections, malaria, drug-resistant tuberculosis, and cancers;
- Injury to the head or ear;
- Excessive noise, including occupational noise such as that from machinery and explosions;
- Recreational exposure to loud sounds such as that from use of personal audio devices at high volumes and for prolonged periods of time and regular attendance at concerts, nightclubs, bars and sporting events;
- Ageing, in particular due to degeneration of sensory cells; and wax or foreign bodies blocking the ear canal.
Among children, chronic otitis media is a common cause of hearing loss.