Explosive deafness refers to a sudden hearing impairment caused by intense shock and short-term strong impulse noise to the auditory system, often resulting from explosions in both peacetime and wartime. The primary injury occurs in the inner ear, but the eardrum or ossicular chain is also frequently damaged to varying degrees. The severity of deafness is usually related to factors such as the distance from the explosion source, the magnitude of the shockwave pressure, the duration of exposure, head position, the presence of obstacles, and individual susceptibility.

bubble_chart Pathogen

1. The inner ear

is generally injured from the base of the cochlea to the middle of the second turn. Initially, there is degeneration, displacement, or partial detachment of the outer hair cells and supporting cells of the spiral organ from the basement membrane. In severe cases, all cells undergo significant degeneration, leading to the disappearance of the spiral organ, degeneration of the cochlear ganglion, and hemorrhage in the endolymphatic space. Changes in the vestibular portion are generally milder.

2. The middle ear

may exhibit symptoms ranging from grade I congestion of the tympanic membrane to rupture, fracture or dislocation of the auditory ossicles, rupture of the chorda tympani nerve, and rupture of the round window membrane causing perilymphatic fistula.

bubble_chart Clinical Manifestations

Blast-induced deafness differs from noise-induced deafness in that the degree of injury to both ears is often asymmetrical, and unilateral damage is not uncommon.

1.deafness

Mild cases are temporary, while severe cases are permanent. Generally, if recovery does not occur within six months after the injury, it is unlikely to be restored. The deafness is sensorineural or mixed, resulting in diverse audiometric curves, with the typical 4000Hz dip being relatively rare. Sometimes, intense blast sounds can trigger psychological factors, leading to functional inhibition of the auditory center and resulting in functional deafness, often accompanied by symptoms like aphasia. Functional deafness may coexist with blast-induced deafness.

The incidence rate is approximately 50–100%, with persistent cases being more common than intermittent ones, primarily sensorineural in nature. Some patients perceive their deafness as mild, with severe high-pitched tinnitus being their main complaint.

3.Ear pain

The incidence rate is about 20%, mostly caused by tympanic membrane rupture, and is thus short-lived.

4.vertigo

Cases involving labyrinthine concussion or hemorrhage may present with vertigo, spontaneous nystagmus, and balance disorders. Those with cerebral concussion may experience unconsciousness, often followed by persistent vertigo, headache, and dizziness.

5.Tympanic membrane injury or rupture

Manifestations include tympanic membrane congestion, ecchymosis, hemorrhage, or even rupture.

bubble_chart Treatment Measures

Grade I explosive deafness can partially recover, and treatment should begin no later than 2 months after injury. Medications that improve inner ear microcirculation and benefit cell metabolism should be administered, such as nicotinic acid, 654-2, vitamins, steroids, coenzyme A, and adenosine triphosphate. Treatment for tympanic membrane trauma is as mentioned earlier. If there is interruption of the ossicular chain or rupture of the round window membrane, surgical repair can be performed.

bubble_chart Prevention

1. Simple Protection

In anticipated situations, utilize favorable terrain and cover to avoid the overpressure of blast waves; lie prone or turn your back to the blast center; open your mouth and perform chewing or swallowing motions; wear ear-protective hats or headscarves; cover your ears with hands or arms, or use oiled cotton to plug the ears.

2. Structural Protection

3. Equipment Protection

Such as various earplugs, earmuffs, and soundproof helmets.

4. Health Monitoring

Individuals with existing sensorineural deafness should not participate in firearms or artillery training; choose open areas without echoes for artillery practice; minimize clustered firing when it does not affect training requirements; conduct regular hearing tests for artillery units, and those found with hearing injuries should suspend training and receive prompt treatment.

5. Early Treatment