[Symptoms and Causes] In late October, a national defense project undertaken by a brigade of the Guangzhou Military Region entered a critical phase. Staff Sergeant Xiao Gao, an engineering machinery operator in the brigade, volunteered for the task and fought continuously, taking turns operating excavators, bulldozers and other heavy machinery. Within a few days, Xiao Gao began to feel dizzy and experienced tinnitus. To ensure project progress, he ignored his body's reactions and continued working on the front line. After a week, Xiao Gao developed headaches, insomnia and other symptoms. He went to the medical unit for examination, where a military doctor gave him a hearing test and diagnosed him with hearing impairment.

　　Hearing impairment refers to decreased hearing, distorted sound perception or repeated hearing, and is a relatively mild form of deafness. There are many causes of the condition, such as congenital inheritance, viral infection and improper medication, but Xiao Gao's cause was noise pollution in the work environment. During this mission, Xiao Gao often worked continuously in a high-noise environment above 90 decibels. Long-term exposure to such a working environment can easily damage auditory cells and the nervous system, and can also cause psychological discomfort such as anxiety and irritability.

　　[Preventive Measures] Officers and soldiers engaged in engineering machinery operation cannot avoid high-noise environments, so what measures should be taken to effectively reduce the harm of noise? First, arrange time reasonably. During construction operations, operators' endurance should be fully considered, and work should be divided into multiple periods, with a 10- to 20-minute rest between each period, to avoid prolonged continuous operation. Two to three people can also be arranged to drive and operate in shifts to reduce the harm noise causes to any one person. Second, wear noise-reduction earplugs. If the work period is long, it is best to wear special protective earplugs, which can achieve a good noise-reduction and protective effect. Third, undergo regular physical examinations. Engineering machinery operators are exposed to noise environments for long periods, so it is necessary to have regular hearing tests to detect symptoms in time and receive professional treatment.

　　[Treatment Recommendations] When engineering machinery operators feel abnormal hearing, they should go to a hospital for testing. If hearing impairment caused by noise is confirmed, two methods—recuperation and treatment—can be adopted according to the severity of the condition to restore hearing. When the condition is mild and hearing loss is not serious, medication is generally not used; it is only necessary to leave the noise environment and rest quietly to recover normal hearing. When the condition is more serious and hearing is severely reduced, accompanied by complications such as dizziness, indigestion and restlessness, medication is needed. Generally, Chinese herbal medicine for promoting blood circulation and dredging collaterals is decocted for oral administration, or drugs that dilate blood vessels can be injected intravenously. For patients with hearing impairment, if they need to enter a high-noise environment again after recovery, they should take self-protection measures to prevent recurrence.