人们把各种不同频率和强度的声波无规律的紊乱组合,波形呈无规则变化的声音,是人们不需要的,起干扰作用的统称为噪声。而与职业有关的,在生产环境中由于生产而产生的噪声叫生产性噪声。当声音的持续时间小于0.5秒,间隔时间大于1秒,声压变化大于40分贝(dB)者称脉冲噪音;声压波动小于5dB者,间隔时间小于1秒的噪声称稳态噪声。无论脉冲或者稳态噪声对机体都有不良的作用,对听觉产生危害,造成听力下降,长期接触可导致病理性改变,造成永久性听力损伤。这种引起听觉器官的损 People have a variety of different frequency and intensity of the irregular wave combination of sound waves were irregular changes in the voice, people do not need to interfere with the role of collectively referred to as noise. Occupational-related noise that is produced as a result of production in a production environment is called productive noise. When the sound duration is less than 0.5 seconds, the interval time is greater than 1 second, the sound pressure changes greater than 40 dB (dB), said impulsive noise; sound pressure fluctuations of less than 5 dB, less than 1 second interval noise is called steady-state noise. Whether impulsive or steady-state noise has an adverse effect on the body, it causes harm to the hearing and causes hearing loss. Long-term exposure can cause pathological changes and cause permanent hearing loss. This causes damage to auditory organs