The deep very low frequency song of the blue whale is difficult for us to hear. Depending on what device you're listening on, it might be too low for your speakers. 

我们人耳很难听到蓝鲸发出的低沉、低频的叫声。你在这段音频中能不能听到它们的叫声取决于你使用的音频播放设备，因为蓝鲸叫声的频率可能低于一些扬声器可播放的频率范围。 

But it's the tell-tale loud pulsing call of the world's largest animal, and it's what scientists managed to capture with an underwater "sound trap" – a microphone and recording rig planted on the sea floor near the Seychelles for a whole year. 

作为世界上最大的动物，蓝鲸发出的叫声颇具辨识度，响亮而富有节奏感。帮助科学家们记录到这种叫声的设备是一种水下 “声音陷阱”，它由一个麦克风和录音装置组成，被放置在塞舌尔附近水域的海床上一整年。

Painstaking analysis of all those hours of sound revealed that blue whales spend months in the tropical waters around the tiny island nation. 

科学家们对录制的大量音频进行了细致的分析，发现蓝鲸在小面积岛国塞舌尔周围的热带水域生活了几个月的时间。 

The researchers have described this as a conservation win – evidence that the population has recovered decades after a ban on commercial whaling. 

研究人员称蓝鲸的回归是一个动物保护的成功案例 —— 在禁止商业捕鲸几十年后，蓝鲸的数量已经恢复。 

词汇表

frequency 频率
tell-tale 泄露秘密的，足以辨识的
pulsing 脉冲的，节奏强烈的
recording rig 录音装置
painstaking 精心的，仔细的
whaling 捕鲸（活动）