电动汽车引起城市交通噪声变化初探

Preliminary Study on Changes of Urban Road Traffic Noise caused by Electric Vehicles

燃油汽车尤其是公交车等大型车辆的加速噪声较高,而电动汽车的电动机运行时辐射噪声相对较小、频率较高。电动汽车替代燃油汽车对降低城市交通噪声具有一定效果,同时,人对交通噪声的主观感受也将产生变化。因此,尝试从主、客观方面对电动汽车所引起的城市交通噪声变化进行探索。首先,采集电动和燃油汽车包括公交车和小汽车的通过噪声样本,对样本进行分析,根据声能量叠加原理和1小时等效A声级的概念,计算电动车替代燃油车后1小时等效A声级的降低量,该降低量取决于车流量以及电动汽车的替代比例。此外,利用汽车通过噪声样本进行主观评价实验。结果显示,评价人员一致认为电动汽车的通过噪声听觉感受较好,电动公交车和小汽车的评价结果都处于满意的范畴,燃油汽车的结果则相反,燃油公交车通过噪声的满意度极低。因此,相对于燃油汽车,电动汽车在声环境改善和提升人的听觉体验方面具有优势。

Accelerating noises of conventional vehicles are usually very loud,especially those of heavy vehicles like buses etc.While the noise of electric vehicles is relatively light but its frequencies are higher.Replacing the conventional vehicles by electric ones would help to reduce the urban road traffic noise.Meanwhile,people’s subjective experiences to the traffic noise would also change.Thus,in this paper the changes of the urban traffic noise were explored from both physical and subjective aspects.Firstly,the pass-by accelerating noises of vehicles,including conventional and electric buses and cars,were recorded.According to the principle of sound energy superposition and the concept of equivalent continuous A-weighted sound pressure level per hour(LAeq,1h),the reduction amount of the LAeq,1h produced by replacing conventional vehicles with electric ones was calculated.This reduction amount depends on the traffic flow and the proportion of electric vehicles.In addition,subjective experiments were performed using the samples of pass-by accelerating noises of vehicles.Results showed that the auditory experiences of electric vehicles’noises were better,and their satisfaction was high,while that of conventional vehicles was low,especially for buses.In a summary,compared with conventional vehicles,electric ones have the superiority in the aspects of improving the urban sound environment and raising people’s auditory experiences.