Chinese name: noise English name: noise Definition 1: sound that interferes with people's rest, study and work, and can cause psychological and physiological changes. Applied disciplines: geography (first level); environmental geography (second level) Definition 2: sounds of different frequencies and intensities irregularly combined together. E.g. electrical noise, mechanical noise, which can be extended to any unwanted disturbance. Applied disciplines: mechanical engineering (primary discipline); vibration and shock (secondary discipline); mechanical vibration (tertiary discipline)
A noise level of 30 to 40 decibels is a relatively quiet and normal environment; more than 50 decibels will affect sleep and rest. Due to insufficient rest, fatigue can not be eliminated, normal physiological functions will be affected to a certain extent; 70 decibels or more to interfere with the conversation, resulting in distraction, mental inattention, affecting the efficiency of the workplace, and even accidents; long-term work or live in a noise environment of more than 90 decibels, will seriously affect the hearing and lead to the occurrence of other diseases.