And we placed infrasonic microphones around the elephants as we did these experiments.

在进实验时，我们把次声传声器放置在大象周围。

But it travels even further through the earth as infrasonic rumbles.

但随着次声波的隆隆声，它在球传播得更远。

The system, the firm claims, produces frequencies from infrasonic to ultrasonic that are " essentially capable of effectively simulating any ship" .

该公司声称，该系统产生从次声波到超声波的频率，“基够有效模拟任何船只”。

And it turns out they're communicating to each other in infrasonic rumbles to warn each other of the threat of bees and to stay away from the area.

后来发现它们在次声波段隆隆低语交流来警告彼此蜜蜂的威胁并且远离蜜蜂所在区域。