Researchers observed lip smacking at an average of 4.15 hertz.

研究人员观察到咂嘴的平均频率为4.15赫兹。

That's right. All other monkeys and apes can do is called lip smacking – rapidly moving their jaws, lips and their tongues.

猴子和猿都会吧嗒嘴——迅速移动颚、 嘴唇和舌头。

(lips smacking) - Is there lipstick on me?

（咂嘴）——我身上有口红吗？

(lips smacking) (crunching) - Do you like it, Theo?

（咂嘴）（嘎吱嘎吱） - 你喜欢它吗，西奥？

(lips smacking) I don't know how I feel about just eating that.

（咂嘴）我不知道吃这个感觉如何。

That's it! So – lip smacking and vocalisations – together are maybe a possible step between the sounds of other monkeys – and human speech.

就是这样！因此边吧嗒嘴边发声或许是其他猴子所发出的声音与人类语言之间的一步之差。