hum reduction factor

例句：

1. 1.The hum reduction factor of the new airconditioner is significantly higher than that of theold one.
   新型空调的声波减少因子明显高于旧款。
2. 2. The team used aspecial device to reduce the hum in theroom.
   该团队使用了一种特殊设备来减少房间内的嗡嗡声。
3. 3. Theengineer calculated the hum reductionfactor for the new design.
   工程师为新设计计算了声波减少因子。