Sound Level Meter: The Impact of Environmental Noise on Various Industries and Daily Life
In general, we often refer to unwanted sounds as noise, such as environmental noise, traffic noise, etc. The sound of a piano is music, but for those who are studying or sleeping, it becomes a disturbing noise.
According to different sound sources, noise can be divided into mechanical noise, aerodynamic noise, and electromagnetic noise. Mechanical noise is mainly generated by solid vibration. During mechanical operation, due to mechanical impact, friction, alternating mechanical stress, and uneven power during operation, the metal plates, gears, bearings, etc. of the machinery vibrate, thereby radiating mechanical noise, such as noise generated by machine tools, looms, ball mills, etc. When gases move at high speed relative to each other or other objects (solid or liquid), gas disturbances are caused by viscous effects, resulting in aerodynamic noise such as the intake and exhaust noise of various fans, the roar of jet aircraft, the exhaust of internal combustion engines, and the exhaust of gas storage tanks. The rapid expansion of surrounding air caused by explosions is also an aerodynamic noise. Electromagnetic noise is the noise generated by the vibration of electromagnetic components caused by magnetic field pulsation and magnetostriction, such as the noise produced by transformers.
Urban environmental noise plays an important role in noise research, mainly coming from traffic noise, industrial noise, construction noise, and social life noise. Due to the increasing number of motor vehicles in cities and the widespread use of supersonic aircraft, the noise generated by transportation vehicles such as cars, tractors, trains, airplanes, etc. has become one of the main sources of urban environmental noise pollution. Industrial noise not only poses a direct threat to production workers, but also affects nearby residents. In industrial noise, the noise level in textile factories is between 90-106dB, while in the mechanical industry it is between 80-120dB. Large ball mills and blowers have noise levels above 130dB. Industrial noise is the main cause of noise induced hearing loss. Construction noise is caused by the use of various construction machinery such as pile drivers, mixers, and cutting machines on construction sites. Noise from social activities and family life is also common, for example, excessive use of loudspeakers for promotional activities can produce annoying noise. In social life, improper use of radios, recorders, and televisions can also become a source of noise that interferes with neighbors in many cases. Household appliances such as electric fans, refrigerators, washing machines, etc., if designed and manufactured improperly or used improperly, can also become sources of noise.
