All sounds that hinder people's normal rest, study and work, as well as sounds that interfere with the sounds people want to hear, are all noise. In this sense, there are many sources of noise, such as the sound of cars on the street, the sound of talking in a quiet library, the sound of machinery on construction sites, and the excessively loud sound of neighboring TV sets.

Noise is a kind of physical pollution. It refers to the unwanted and annoying sound of people. It is considered to be the third largest public hazard after air pollution and water pollution, and causes great harm to human health.

Test items:

1. Environmental noise (regional environmental noise, road traffic noise)

2. Noise at the boundary of industrial enterprises

3. Noise of social living environment

4. Noise at the boundary of construction site

5. Noise and vibration in the workplace