Adult humans laugh primarily on the exhale, but human babies laugh on the inhale and the exhale—as do chimps. Christopher Intagliata reports.

成年人主要靠呼气来笑，而婴儿则同时靠吸气和呼气来笑，黑猩猩也是这样。Christopher Intagliata报道。

撰文播音：克里斯托弗·因塔利亚塔（Christopher Intagliata）

翻译：邱燕宁

审校：张清越

A baby's laugh is unmistakable:  that sets a baby's laugh apart from ours: babies laugh on the exhale and on the inhale. Whereas adult humans "tend to laugh predominantly on the exhale. The classic kind of 'ha ha ha.'" Disa Sauter, a psychologist who studies emotions at the University of Amsterdam. 

婴儿的笑声是独一无二的：.<片段:婴儿笑>，但是除了它的尖叫和高音调的特性之外，还有另一个因素使婴儿的笑声与我们的不同：婴儿在呼气和吸气时都可以笑。而成年人类则主要是在呼气时发笑，是典型的“哈哈哈”笑声。阿姆斯特丹大学研究情绪问题的心理学家迪莎·索特（Disa Sauter）说。

Sauter and her colleagues collected 44 samples of babies laughing, from the ages of 3 months…

Sauter和她的同事收集了44个婴儿笑声的样本，从3个月大的.….<片段:3个月>到10个月.….<片段:10个月>一直到18个月.<片段:18个月>。

They played the samples for about 100 untrained volunteers, and asked them to deconstruct the laughs. Were the babies laughing on the inhale, the exhale, or both? "And there we find a nice relationship between the age of the baby and the amount of the laughter happening on the inhale." 

他们为大约100名未经训练的志愿者播放了样本，并要求他们解构笑声。婴儿是在吸气、呼气，还是在两者兼而有之的时候笑的？“我们从而发现婴儿的年龄和吸气时发生的笑声数量之间有很好的关系。”

The younger the baby, the more laughs on the inhale. Because remember, our laughs gravitate towards the exhale as we age. And Sauter thinks one reason for that could be that we gain more vocal control as we learn to talk: speaking also happens primarily on the exhale.

婴儿越小，越容易在吸气时笑。因为记住，我们的笑声随着年龄的增长而多受我们的呼气引导。索特认为其中一个原因可能是，当我们学会说话时，我们获得了更多的发声控制：说话也主要发生在呼气时。

She presented the preliminary findings at a meeting of the Acoustical Society of America, in Victoria, Canada. [Disa Sauter et al., How do babies laugh?] The researchers are in the process of checking the judgments of the volunteers against those of professional phoneticians. 

她在加拿大维多利亚举行的美国声学学会会议上介绍了初步发现。研究人员正在检查志愿者与专业语音学家的判断。

As it happens: human babies aren't the only primates who laugh both breathing our and breathing in.

碰巧：人类婴儿不是唯一呼气和吸气时都会笑的灵长类动物。<片段：黑猩猩>黑猩猩也会这么做。

"They laugh like 'hoo hoo hoo.' They laugh more continuously while inhaling and exhaling. It's totally difficult to do on purpose." 

“他们笑起来声音像‘呼呼呼’，吸气呼气时笑得更加连续。这是很难做到的。”

But Sauter, I thought, pulled off a pretty good impression. "I'll take that as a compliment! "

但我想，Sauter给我留下了很好的印象。“我会把它当作恭维话！<笑>”