次声振动 meaning in Chinese

infra-acoustic vibration

So they ' re vibrating sub sonically
所以它们在用次声振动
The wave length of infra - sound is quite long : typical infra - sound from the eye of a typhoon has a 4 to 8 second cycle 0 . 25 to 0 . 125 hz , meaning that its wavelength is a few kilo - metres long
次声波的波长很长，例如台台风眼所产生的次声振动周期约秒0 . 250 . 125赫兹，波长便可达数公里。