Ear Nose | Otorhinolaryngology | Hearing Loss (Symptom)
Deafness, or hearing impairment, is a partial or total inability to hear where the ability would usually be expected. Hearing loss or deafness may be present at birth (congenital) or may become apparent later in life (acquired).
To understand how hearing loss occurs, it can be helpful to understand how a person hears. Aging and prolonged exposure to loud noise may cause wear and tear on the hairs or nerve cells in the cochlea that send sound signals to the brain. When these hairs or nerve cells are damaged or missing, electrical signals are not transmitted as efficiently, and hearing loss occurs. Higher pitched tones may become muffled. It may become difficult for a person to pick out words against background noise. Heredity may make an individual more prone to these changes. This type of hearing loss is known as sensorineural hearing loss, which is permanent.
Doctors believe that heredity and chronic exposure to loud noises are the main factors that contribute to hearing loss over time. Other factors, such as earwax blockage, can prevent ears from conducting sounds as well as they should.
A gradual buildup of earwax can block the ear canal and prevent conduction of sound waves. Earwax blockage is a cause of hearing loss among people of all ages. This causes conductive hearing loss, which usually can be restored with earwax removal.
Ear infection and abnormal bone growths or tumours may be another cause of hearing loss. In the outer or middle ear, any of these can cause hearing loss: ruptured eardrum (tympanic membrane perforation), loud blasts of noise, sudden changes in pressure, poking eardrum with an object and infection causing eardrum to rupture.
Signs and symptoms of hearing loss may include: muffling of speech and other sounds, difficulty understanding words, especially against background noise or in a crowd of people, frequently asking others to speak more slowly, clearly and loudly, needing to turn up the volume of the television or radio, withdrawal from conversations, avoidance of some social settings.