Rarely occurring is complete deafnessthe result of a bilateral fracture perceiving sound cells of the cochlea and the auditory nerve sometimes. In such cases, to restore hearing requires electrical stimulation of the auditory nerve or the auditory centers of the brain. It uses a very sophisticated device - cochlear (replaced by the properties of the cochlea) or brainstem (in violation of the auditory nerve) implants. By operation into the skull bone is inserted into the thinnest wire - electrode and fed electrical impulses directly to the auditory nerve. This correction method requires a long and difficult rehabilitation.
Contributing factors: the presence in the family suffering from hearing loss or other hereditary diseases (eg, hypoplasia bones of the inner ear), transferred during pregnancy rubella, maternal syphilis, medications that are harmful to the ear, prolonged oxygen deficiency of the fetus during labor and congenital anomalies of the ear and nose.
The sudden deafness - a sudden loss of hearing person who previously had no reason to complain about the hearing. In such cases it is necessary to take urgent measures to restore hearing.
The causes and contributing factors are manifold:
- acute infections (especially mumps as well as measles, German measles, flu, shingles and infectious mononucleosis);
- diabetes, decreased thyroid function, high concentrations of fat and cholesterol;
- high blood pressure and hardening of the arteries;
- head trauma and brain tumor;
- medicines that are harmful to the ear;
- neurological diseases (eg, multiple sclerosis);
- blood disorders (eg, leukemia, and increased blood clotting).
Sudden hearing loss may produce symptomsconductive, sensorineural and mixed hearing loss, depending on the reasons that caused it. If the hearing has decreased as a result of exposure to noise, at first a person loses the ability to hear sounds of certain frequencies (around 4000 Hz), and then worse and worse distinguishes the sounds of all frequencies.
Hearing loss from noise
Hearing loss can occur as a result ofimpact noise, it may be temporary or permanent. Hearing impairment occur with prolonged exposure to noise (85-90 dB) and short-term exposure to very loud noise (90 dB). This form of hearing loss is common in workers exposed to constant influence of industrial noise, as well as the military, hunters, and rock musicians.
Senile deafness develops and progresseswith age. It is caused by the loss of hair cells in the cochlea - the receptor apparatus of the auditory analyzer. For senile hearing loss is characterized by ringing in the ears, and the inability to understand speech.