overall noise level meaning in English

总噪声电平

The contribution to the increase in the overall noise level from the new road must be at least 1 db
新建道路噪音导致整体噪音声级的升幅最少需达1分贝a 。
The predicted overall noise level from the new road together with other traffic noise in the vicinity must be above
新建道路加上附近其他道路的交通噪音的预测整体噪音声级，必须达
The exhaust noise is the most common sound source of engine noises , and is usually 10 to 15db higher than the overall noise level of the engine
排气噪声是发动机噪声中最主要的声源，其噪声一般要比发动机整机噪声高出10 ~ 15db （ a ）。
It has been proved that some structural adjustments may somehow cut down on the surface radiation noise of the engine , thus bringing down the overall noise level . basically it means to increase the structural rigidity and the damping so as to reduce the structural surface response under the same exciting force
实践表明，在结构上采取措施可以一定幅度地降低发动机的表面辐射噪声，从而降低整机噪声。控制的基本措施是增加结构刚度和阻尼，使得在同样的激振力作用下减少结构表面响应。