How to prevent blast deafness

Zhou Ling, director of the Department of Otorhinolaryngology, the First Affiliated Hospital of Heilongjiang University of Traditional Chinese Medicine, introduced that decussive deafness, also known as acute acoustic deafness, is a hearing organ damage caused by a sudden strong knock or sound. Most of the fire drills or other sudden bangs occurred during military exercises and wars. They also occurred in blasting operations such as mountain collapse and road construction mining. They were also seen in some accidental explosions in life such as boilers, gas tanks, pressure cookers and household appliances. In the TV sets, refrigerators, etc., there are also people who are deaf due to firecrackers. During the war, due to the massive use of weapons such as blockbusters and large-calibre artillery, the incidence rate increased significantly.

When people are exposed to the original shock wave caused by explosion and firearms in the exposed space, the air pressure of the external auditory canal suddenly changes and reaches the highest value in an instant. At this time, the body does not have time to adjust the pressure inside and outside the tympanic membrane through the adjustment of the eustachian tube. Obvious pressure difference. When the latter exceeds a certain physiological limit, it can cause tympanic membrane rupture, middle ear damage such as ossicular fracture, dislocation and intratympanic hemorrhage. The powerful pressure wave can be perforated and directly applied to the snail window to the perilymph. If the tympanic membrane has not yet ruptured, the pressure wave acts on the tympanic membrane and is transmitted to the perilymph through the ossicular chain and the vestibular window. The above direct or indirect pressure can cause fluid pressure of the perilymph fluid and pass through the vestibular or basement membrane to the endolymph in the cochlear tube, causing the inner lymph fluid to fluctuate drastically, thereby causing the inner ear screw, the auditory nerve fiber and the blood vessel. Damage.

After the detonation, there were temporary severe deafness, and some could not hear any sound in the first few minutes, but soon heard the sound, and then felt various symptoms such as tinnitus, earache, dizziness, etc. Systemic injuries, such as during explosions and firearms, can be associated with lung damage such as alveolar rupture, pulmonary hemorrhage, and pulmonary edema. Can also cause gastrointestinal bleeding, perforation, hepatosplenoid hematoma, rupture, bladder rupture, myocardial contusion, eye contusion and concussion. Severe blast injury can cause craniocerebral trauma at the same time, and severe systemic symptoms such as shock and coma.

Director Zhou Ling said that the key to the violent deafness is prevention.

For those engaged in knocking, they should strengthen the prevention of knowledge, so that they should not be confused when an acute accident occurs; usually wear protective equipment such as earplugs, earmuffs, anti-sound caps, etc.; lack of protective materials and predict that when knocking is about to occur The simplest method of protection is to insert a cotton ball into the ear canal; in an emergency, two small fingers can be inserted into the external ear canal of each side, and when lying in an emergency, back to the source of the explosion, the mouth can be used to reduce the degree of injury. The sound insulation effect of earplugs is generally up to 20~35dB. The sound insulation effect of the earmuffs is higher than that of the earplugs, which can reach 30~45dB, but it is inconvenient to use. The cotton ball ear can be separated by 10~15dB.

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