2. The energy of noise
2.1. The energy generated noise
The propagation of sound that is in the air given the pressure that pressure into energy for the medium
volatility.
2.2. Energy of the city noise
For now the city transportation, and the crowd noise at the data-intensive surveys, traffic density, the
higher the traffic speed, noise is also greater.
So the more noise in the unit times to the surrounding air the greater the energy the moment of release.
Vehicle noise is between 80-100 decibels, a bus generally issued 90 dB noises.
3. City noise of electric vehicles
With the acceleration of the process of modernization and development of automobile industry, urban
vehicle radiated noise; energy represents about 75% of ambient noise, the urban environment, the main
noise source. Electric Vehicle noise comes mainly from vehicle dynamic systems and non-power system
noise. Power system includes a vehicle and vehicle speed, turning on the engine intake and exhaust noise
produced when, and when the drive engine noise, body vibration and noise. Non-power system is mainly
car horns, brake noise. Electric vehicle is a vehicle power supply as the power, in whole or in part by the
motor drive the wheels driving, the advantage is the ability to reduce oil usage, so as to achieve energy
conservation, energy conservation purposes.