Now after I play back these humpback calls, I'll play blue whale calls, but they have to be sped up because they're so low in frequency that you wouldn't be able to hear it otherwise.
在我播放了这些座头鲸的叫声之后， 我要播放一些蓝鲸的叫声，但我不得不加快这些声音， 因为它们的频率太低了， 否则大家就听不到它们了。