noise-induced deafness
Introduction
Introduction to noise deafness Noise deafness is a slow and progressive sensorineural deafness due to long-term hearing loss of hearing. Early manifestation is auditory fatigue. It can be gradually recovered after leaving the noise environment. It is difficult to recover after a long time, and eventually it is a sensorineural hearing loss. In addition to hearing damage, noise can also cause headache, dizziness, insomnia, high blood pressure, etc., affecting the peristalsis and secretion of the stomach. The main symptoms of noise deafness are progressive hearing loss and tinnitus. The early hearing loss is at 4,000 Hz. Therefore, it has no obvious effect on ordinary speech. Only in the audiometer examination, the hearing damage gradually develops to the high and low frequencies. It is generally declining. At this time, hearing impairment is felt. In severe cases, it can be completely paralyzed. Tinnitus and deafness can occur at the same time. It can also occur alone. It is often high-pitched tinnitus and disturbs day and night. basic knowledge The proportion of illness: 0.005% Susceptible people: no special people Mode of infection: non-infectious Complications: tinnitus
Cause
Cause of noise deafness
When the noise exceeds 85~90dB intensity, it will cause damage to the cochlea. As for the degree of damage, it is related to the following factors:
Individual susceptibility (25%):
Those who are old and weak, who have suffered from sensorineural deafness, are susceptible to noise damage, and the influence of those with middle ear disease is still divided. Some people think that the tympanic membrane perforation is interrupted, and the noise damage is relatively high. light.
Noise intensity (20%):
The frequency of onset of noise deafness increases with increasing noise intensity. There may be headache, dizziness, insomnia, fatigue, memory loss, unresponsiveness, depression, palpitations, elevated blood pressure, nausea, loss of appetite, indigestion, etc.
Contact time (25%):
Continuous contact is greater than intermittent contact damage. The longer the contact noise period, the heavier the hearing damage. The closer the noise source is, the more susceptible the hearing will be.
Prevention
Noise deafness prevention
1. Control the source of noise
This is the most active and fundamental method. In the construction plant, when installing the machine, all kinds of soundproofing, shockproof and sound absorbing measures should be adopted. For example, the noise workshop is separated from other workshops, the trees are planted in the middle, and the wall and ceiling of the workshop are absorbing sound. Material, machine installation density should be dilute, between the machine and the foundation, between the metal surface and the surface with appropriate filling materials, pipe noise can be used to prevent sound, the airflow noise can be silencer or expand the vent, so that the noise is reduced To the national protection standards (85 ~ 90dB).
2. Reduce contact time
If you work in the soundproof room, or reduce the daily, weekly contact noise time, you can also reduce the incidence rate, and can also rotate the work according to the actual situation, but also reduce hearing damage.
3. Ear sound insulation
Wearing earplugs, earmuffs, soundproof caps and other soundproofing equipment, generally in the 80dB noise environment for long-term work should be equipped with simple earplugs, 90dB or more, you must use protective tools, simple cotton can be used to close the outer ear canal, and then apply Vaseline, Its sound insulation value can reach 30dB.
4. Health monitoring
Listening should be checked before employment. People with sensorineural deafness and noise sensitivity should avoid working in a strong noise environment. For those who are exposed to noise, they should check their hearing regularly, and find early hearing damage in time and give proper treatment.
5. Strive for early treatment
Complication
Noise deafness complications Complications, tinnitus
Prolonged periods will cause irreversible neuropathological damage and can be deaf for life.
Symptom
Noise deafness symptoms Common symptoms Hearing loss Deafness Tinnitus Lack of insomnia Nausea fatigue Responsive hearing bone deformity Loss of appetite
The main symptoms are progressive hearing loss and tinnitus. The early hearing loss is at 4,000 Hz. Therefore, it has no obvious effect on ordinary speech. Only in the audiometer examination, the hearing damage gradually develops to the high and low frequencies, and finally declines. Hearing disorder, severe cases can be full, tinnitus and deafness can occur at the same time, can also occur alone, often high-pitched tinnitus, day and night troubles.
Due to the influence of long-term noise stimulation, the inner ear hair cells are destroyed, the auger and spiral ganglion degenerative degeneration, and the lesions at the end of the basement of the cochlea and the second circle are most obvious. This part is subjected to 4000 Hz sound stimulation. The reason for being susceptible to noise damage may be due to the proximity to the tympanic cavity and the fact that the blood circulation is poor between the two windows. Another way of thinking is that the two vortexes, which are the bass wave and the high sound wave, meet at different points. The tension is especially increased, which is easy to cause local tissue deformation. Some people think that this is related to the resonance of the external auditory canal. Because the resonance frequency of the external auditory canal is about 3000~4000Hz, it can increase the harm of this frequency noise to the inner ear, and the noise stimulates the animal. Tests have shown that the inner ear damage is mainly in the cochlear tube and the balloon, while the elliptical sac is slight and the semicircular canal is not damaged.
Progressive hearing loss
When you start to contact the noise, the hearing is slightly dull. If you leave the noise, the hearing recovers after a few minutes. This phenomenon is called auditory adaptation. If it is sustained, strong noise, the hearing is obviously slow, and after a few hours, the hearing recovers. At this time, it is called auditory fatigue. If it is further subjected to noise stimulation, it will lead to hearing damage, and it is not easy to recover by itself. The hearing loss of 4000Hz is displayed in the early stage, and the hearing curve is valley-shaped. Afterwards, the valley shape is gradually deepened, and 2000Hz and 8000Hz are also affected. As a result, the hearing is down-slashed, and the curve is generally symmetrical. The asymmetry is mostly with other ear diseases or individual special cases.
2. Tinnitus
May appear earlier than deafness, or develop at the same time as deafness, high-pitched, often bothering day and night.
3. Systemic response
There may be headache, dizziness, insomnia, fatigue, memory loss, unresponsiveness, depression, palpitations, elevated blood pressure, nausea, loss of appetite, indigestion, etc.
Examine
Noise deafness check
There was no abnormality in the general examination of the ear, nose and throat. Pure audio and audiometry is inductive, and the development of imaging also contributes to the diagnosis of sensorineural deafness. In recent years, research hotspots on auditory and imaging have focused on functional imaging technology. Its characteristics reflecting vital signs are different from structural imaging, including functional magnetic resonance imaging and positron emission tomography.
Diagnosis
Diagnosis of noise deafness
(1) Infectious pathogenic sputum: various acute infectious diseases, bacterial or viral infections. Such as epidemic encephalitis, mumps, purulent meningitis, measles, scarlet fever, influenza, herpes zoster, typhoid, etc. can damage the inner ear and cause different light and weight of sensorineural hearing loss.
(2) drug toxicity : more common in aminoglycoside antibiotics, such as gentamicin, kanamycin, polymyxin, dihydrostreptomycin, neomycin, etc., other drugs such as quinine, water Salicylic acid, cisplatin, etc. can cause sensorineural hearing loss, and ear drug poisoning is closely related to the susceptibility of the body.
(3) senile sputum: mostly due to hardening of the arteries, bone hyperplasia, resulting in insufficient blood supply, degenerative lesions, leading to hearing loss.
(4) Traumatic sputum: craniocerebral trauma and humeral fracture damage to the inner ear structure, resulting in inner ear hemorrhage, or damage caused by strong shock in the inner ear, can lead to sensorineural hearing loss, sometimes accompanied by tinnitus, dizziness. Light can be recovered, and ear surgery can also cause deafness by accidentally injuring the structure of the inner ear.
(5) Sudden convulsions: It is a sensorineural hearing loss that occurs suddenly and whose cause is unknown. At present, it is believed that acute inner ear microcirculatory disorders and viral infections are common causes of this disease.
(6) Knocking sputum: Acute hearing loss caused by sudden strong pressure waves and strong impulse noise. The tympanic membrane and cochlea are the most vulnerable parts of the hearing device. When a person is exposed to noise above 90 dB (A), cochlear damage can occur, and if the intensity exceeds 120 dB, it can cause permanent paralysis.
