Cens shooting

Causes of Hearing Loss

Although age (presbyacusis) is considered to be one of the primary causes for hearing loss this is not necessarily always the case.  Hearing loss (temporary or permanent) can occur at any time and may be as a result of any of the following:

Acquired hearing loss:

Traumatic:
 Physical trauma – blow to the head
 Noise trauma – exposure to steady rate of noise
 Acoustic trauma – exposure to repeated loud sounds such as gun fire
 Blast injury – explosions
 Barotrauma – pressure changes due to flying or diving
 Miscellaneous – radiation exposure, electric shock

Iatrogenic:
 Surgical e.g. poor ear syringing techniques, post surgery operations such as a stapedectomy
 Pharmacological – certain drugs

Infective:
 Viral – measles, mumps, herpes zoster (shingles)
 Bacterial – upper respiratory infections e.g. colds & flu which can lead to middle ear infections
 Fungus – Otomycosis (fungus in the outer ear)
 Parasitic – meningitis

Neoplastic:
 Cancer of the middle ear, leukaemia, vestibulocochlea schwannoma (acoustic neuroma)

Metabolic:
 Hormonal – Myxodema (hypothyroidism), diabetes, acromegaly – can cause excessive growth in children or soft tissue growth in adults
 Others – Dyslipidaemia (too much fat in the blood), hyperuricaemia (gout-excessive uric acid in blood), renal failure where kidneys cannot cleanse body of impurities, causing toxicity

Vascular:
 Arteriosclerosis (hardening of the arteries), hyper-tension (high blood pressure), other circulatory disorders

Auto immune disorders:
 Wegenet’s granulomatosis (bone lesion), polyarteritis nodosa (disease of artery wall), Bechets Syndrome

Miscellaneous disorders:
 Ototoxic substances not iatrogenically introduced such as carbon monoxide, tobacco and alcohol
 Meniere’s disorder


Congenital hearing loss:

Pre-natal:
 Genetically (some 50-60% of all cases are hereditary) – Osteo genesis imperfecta (brittle bones), ushers syndrome, gargoylism (skull/facial deformities), Waardenburgs syndrome, Treacher Collins syndrome, Allports syndrome, Paget’s disease (softening of the bones with age), hereditary presbyacusis. The most common form of hereditary hearing loss is otosclerosis (restriction of middle ear bone movement)
 Pre-natal maternal rubella – Mother contracts German Measles during pregnancy
 Cyto megalovirus (CMV) – Mother contracts this herpes like virus with flu type symptoms
 Ototoxicity
 Congenital syphilis

Peri-natal:
 Premature birth
 Anoxia – oxygen deficiency at birth e.g. umbilical chord twisted around baby’s neck
 Birth Trauma – damage by forceps during delivery
 Rhesus incompatibilities – Rhesus factors in father’s & mother’s blood can cause jaundice