交流声 meaning in English

hum; hum noise; ripple; back drop
◇交流声滤除器 hum filter; 交流声平衡器 hum balancer; 交流声调整 hum adjustment; 交流声消除线圈 hum cancel coil

It is sometimes mistaken for a power supply hum
有时候，亚音频会被错误的认为是电源交流声。
It flew with the speed of the wind and gave forth a melodious sound ( a humming noise
它以风速飞行，发出了音调优美的声音（交流声？）
The environment - preserved and high efficient power switch design not only saves energy but completely solve the problem of ac noise interference
绿色环保、高效的开关电源设计，既节能，又彻底解决交流声噪音干扰问题。