And when he recorded the vibrations produced by worm grunters and moles digging, their frequencies overlapped substantially.

他记录并对比了蚯蚓召唤术和鼹鼠挖掘时所产生的震动，并发现它们的频率基本相同。

But due to the periodic nature of sinusoids, these waves of different frequencies overlap in a predictable way.

但由于正弦曲线的周期性，这些不同频率的波以可预测的方式重叠。