Humans can recognize emotions across all vocalizing land animals, researchers have found.
研究人员近日发现，人类可以识别所有可发声陆地动物的情感。
The research supports naturalist Charles Darwin's views from over a century ago, when he observed that humans and other animals express their emotions in similar ways.
这项研究支持了一个多世纪以前博物学家达尔文的观点，当时他观察到人类和其他动物用相似的方式来表达自己的情感。
Previous research on the topic of animal vocalizations has suggested that animals understand human emotional sounds.
之前对于动物发声课题的研究已经表明，动物能理解人类情感的声音。
For example, pet owners are usually attuned to this and their pets recognize their emotional outbursts.
举例来说，宠物的主人通常会适应这种情况，而他们的宠物往往能够感受到主人的情绪爆发。
Previous studies have also suggested that acoustic attributes of emotional (aroused) vocalizations are shared across many mammal species, and that humans can use these attributes to determine an animal's emotional state.
之前的研究还表明，哺乳动物的情绪性叫声有许多共性，人类能够通过这些特性去判断动物的情绪状态。

But researchers weren't sure if this also extended to land animals that aren't mammals.
但是研究人员不确定这一现象是否也适用于非哺乳类的陆地动物。
To find out, an international team of researchers gathered the voice recordings of a diverse group of nine different species: The black-capped chickadee, hourglass treefrog, American alligator, common raven, giant panda, barbary macaque and the African bush elephant.
为弄清事实到底如何，一个国际研究小组收集了不同群体共9种不同动物的声音：包括黑顶山雀、沙漏树蛙、美洲短吻鳄、乌鸦、大熊猫、巴巴利猕猴和非洲丛林象。
Then, research participants were asked to listen to the recordings and try to identify the emotional state of the animal who made it.
随后，研究参与者被要求听这些录音，然后辨别出发出这些声音动物的情感状态。
To rule out the possibility that certain sounds may be more recognizable by people who speak certain language, the researchers recruited volunteers who spoke German, English or Mandarin.
为了排除某些声音可以被说某种语言的人识别的这一可能性，研究人员们分别招募了说德语、英语和汉语普通话的志愿者。
The researchers also carried out an acoustic analysis of the sounds on the recordings, comparing the sounds with people's reactions to them and found that humans use many acoustic clues to understand emotional noises made by other animals.
研究人员还对录音中的声音进行了声学分析，通过对比人类对这些声音的反应发现，人类可以使用许多声学线索来理解其他动物发出的富含情感的声音。