Deafness is a condition that is characterized by the total or partial loss of hearing. There is talk of hearing loss when hearing is diminished but still possible and deafness when no sound is heard. There are several types of hearing loss: conductive hearing loss due to a factor affecting the outer ear or the middle ear, and sensorineural hearing loss, the cause of which is located at the inner ear or the path of the nerve providing information to the brain (known in this case as central deafness). Some conditions, such as Meniere's disease
, infections of the ear, a neuroma affecting the auditory nerve or even medications can cause deafness. It can also be congenital, present at birth
or due to major trauma or repeated loud sound. Sometimes the causes are trivial and easily treatable, such as when a foreign body is located in the ear canal, or when there is an excessive build-up of earwax. With age, a decrease in hearing is gradual. Deafness can occur suddenly or gradually.
Symptoms suggestive of early hearing loss are:
- difficulty hearing sounds that surround the subject;
- difficulty following conversations.
In the case of sudden deafness, the patient notices a significant decrease in regards to his previous hearing.
In children, signs that point to congenital deafness are:
- a lack of reaction to noise;
- a delay in learning to talk;
- behavioral problems;
- learning difficulties.
The diagnosis of deafness requires a physical examination, performed using an otoscope, a small instrument equipped with a light that allows the doctor to observe the ear canal and the eardrum. The doctor will examine the inside of the ear to be sure that there is no obstacle or infection. A test using the vibration of a tuning fork is used to distinguish whether the hearing loss is of conductive or sensorineural nature and thus guide the complementary tests. Audiometry is another test to measure the degree of hearing loss. Following the results of these examinations, other specialized tests or an MRI may be performed depending on the origin of suspected deafness.
In children, the use of early childhood screening allows early identification of congenital deafness in the event of discovery of a lack of response to sounds, unexplained by an organic cause: an ABR may be used.
Treatments vary depending on the type of hearing loss and especially the identified cause. Earwax should be removed and any infections treated. Some anatomical problems are sometimes accessible to surgery. If symptoms persist in adults, a hearing aid is sometimes proposed. In congenital deafness, learning sign language, combined with a suitable education, can limit the exclusion generated by this disability.
It is possible to prevent hearing loss by reducing one's exposure to excessive sound, with the use of hearing protection at concerts for example, or during the use of certain noisy machines. It is also recommended to avoid listening to loud music with headphones. Immunization of children, particularly against mumps
is also recommended to avoid the risk of infectious diseases that cause deafness.