Hearing loss is a persistent hearing loss that causes speech perception difficulties (ICD code 10: H90). Hearing loss, with rare exceptions, is the result of a disease or abnormality of the external, middle or inner ear. A serious hearing impairment at birth is almost always the result of dysfunction of the auditory nerve and cannot be improved by medical or surgical treatment. In early and late childhood, the most common cause of hearing impairment is poor functioning of the Eustachian tubes with an accumulation of transparent pale yellow fluid in the middle ear cavity, a disorder called serous or secretory otitis media. In early and middle adulthood, otosclerosis is a common cause of progressive hearing loss. A common cause of hearing loss after 60 years is presbyacusis , a disorder caused by the aging process.
The normal lower limit of the hearing range is 0–20 dB (dB), where 0 dB is the threshold for hearing at a given frequency for people with normal hearing. Deafness is a partial or complete hearing loss, also known as hearing loss. Hearing loss is measured in decibels (dB). Her degree can be classified as follows:
|20-40 dB||light, no whisper|
|41-70 dB||moderate, can not hear colloquial speech|
|71-95 dB||strong, no screams|
|> 95 dB||deep, cannot hear sounds that it would be painful to listen to a person with normal hearing|
Hearing loss is of two types conductive and neurosensory (or sensorineural) .Go
Conductive hearing loss (ICD code 10: H90.0 — H90.2) occurs when sound cannot normally pass through the external ear canal to the eardrum and the bones of the middle ear. Conductive hearing loss is usually associated with a decrease in sound level or a decrease in the ability to hear faint sounds. This type of hearing loss can often be corrected from a medical or surgical point of view.
Epidemiology . Age-related damage to the cochlea is the most important cause of hearing loss. The number of people with hearing loss will increase dramatically from the age of 50. 71.1% of people over 70 and 41.7% of people over 50 have some form of hearing loss.
Hearing loss occurs in men somewhat more often than women.
Hearing loss can be more common in immigrants from regions with higher levels of poverty, poor medical care and low immunization against diseases such as rubella.
The main risk factors for hearing impairment in adults are age and excessive noise exposure.
There are certain risk factors that contribute to the development of specific types of hearing loss (see etiology below), such as previous ear infections, injuries, viral diseases, etc. There are many causes of congenital or childhood deafness that can persist in adulthood. The following are the acquired reasons.
Causes of conductive hearing loss . Accumulation of earwax in the outer ear; infection or inflammation in the outer ear (otitis externa) or in the middle ear (otitis media); rupture or damage to the eardrum caused by injury; otitis media with effusion (inflammation in the middle ear with a concomitant fluid that fills the middle ear space around the bones. The liquid stops the movement of the bones and eardrum and prevents sound from passing through the inner ear.); heredity and other genetic causes; otosclerosis (when mobility of the auditory ossicles is disturbed). Changes in pressure in the environment can lead to temporary conductive hearing loss due to pressure drop in the outer and middle ear. This can happen when you change the height, when you are on a plane or when a train enters a tunnel.
Conductive hearing loss can almost always be partially or fully restored with medication or surgery.Go
In children, hearing loss occurs most often as a consequence of acute and chronic otitis media . The decrease in hearing is caused in these cases by persistent changes in the middle ear - perforations of the eardrum, scars, adhesions, resulting in impaired mobility of the eardrum and the chain of auditory ossicles. The most severe hearing loss develops as a result of pathological processes in the inner ear and the auditory nerve ; most often this is observed in infectious diseases ( scarlet fever , measles, flu). Sometimes hearing loss is congenital, i.e. it occurs as a result of a developmental disorder of the organ of hearing in the embryonic period. The reasons for such a violation are the same as for deafness (see). Congenital hearing loss, as well as hearing loss arising in early childhood, can lead to a violation of the child's speech development. The degree and nature of speech deficiency in hearing-impaired children varies from a slight disturbance in the pronunciation of individual speech sounds to a deep general underdevelopment of speech - and depends on the degree of hearing impairment, the time of hearing loss and the developmental conditions of the child.
In the occurrence of hearing loss in adults, a significant role is played by otosclerosis (see), prolonged exposure to industrial noise and vibrations, intoxication with household and industrial poisons (carbon monoxide, mercury , lead ), impaired blood supply to the inner ear in atherosclerosis, age-related degenerative-atrophic changes in the inner ear , auditory nerve and auditory centers of the cerebral cortex (senile hearing loss, or presbyacus). There are cases of persistent hearing loss in both adults and children after the use of certain drugs ( quinine , streptomycin , neomycin, kanamycin).
Hearing loss can be expressed in varying degrees. For practical purposes, there are three degrees of hearing loss - mild, moderate and severe. To mild hearing loss include such a decrease in hearing, in which whisper speech varies at a distance of 1-3 m, and conversational - at a distance of more than 4 liters. With an average hearing loss, whispers are perceived at a distance of less than 1 m, and conversational - at a distance of 2-4 m. With severe hearing loss, whisper speech does not differ even near the ear, while conversational speech is perceived at a distance less than 2 m.
Treatment . Although there are, as a rule, persistent changes in hearing loss in the auditory organ, in some cases it is possible to obtain an improvement in hearing by conservative ( ear blowing , air massage of the eardrum, physiotherapy , strychnine preparations, nicotinic acid, vitamin B1 , aloe extract) and surgical treatment . From surgical methods, the most widely used are operations on the stapes (see Otosclerosis). Hearing aids (see. Hearing aids ) and training in visual perception of speech (reading from the lips) have a significant help with hearing loss. Children suffering from hearing loss and having abnormalities in speech development are enrolled in special schools for hearing impaired (deaf) children.
Preventive measures are the same as for the prevention of deafness (see).
Features of speech development in children with hearing loss . Hearing impaired children distinguish all vowel sounds, a part of consonants and familiar words pronounced in a voice of normal volume. Depending on the degree of hearing loss, there is a greater or lesser limitation of vocabulary, accompanied by incorrect pronunciation of words. A hearing-impaired child replaces some words with others that are similar in meaning (instead of “cutting” says “knife”, etc.), mixes voiced sounds with deaf sounds, hissing with whistles, hard with soft ones. With severe hearing loss, the words are distorted beyond recognition. They are built from syllables standing in the word under the stress, for example, “notes” - scissors, etc. In the letter, the hearing impaired schoolchildren replace one letter with another, skip letters that do not stand under the stress, make generic and case errors.
Timely recognition of hearing loss, special events that allow the child to more fully perceive the speech of others, create favorable conditions for the development of speech. Special children's institutions - kindergartens and schools (boarding schools) - have two departments: in the first school, children who speak only with minor defects in pronunciation study; in the second - children with a deep underdevelopment of speech. With a decrease in hearing, accompanied by small defects in pronunciation and writing, the child can be enrolled in a public school, subject to additional classes in speech development.