According to Ethnologue, more than 3,000 languages are at risk, usually because children are no longer learning them in favour of a dominant language. When a language dies, unique knowledge goes with it: plant names, techniques, stories. The UN declared 2022–2032 the International Decade of Indigenous Languages, led by UNESCO.
In Kuşköy, a mountain village in northern Turkey, people talk across valleys by whistling Turkish. A 2015 study showed that whistled Turkish draws on both hemispheres fairly evenly, whereas spoken Turkish relies mostly on the left. The physical form of the signal, it turns out, matters to the brain.
Speech has no gaps between words. In 1996, researchers played 8-month-old babies a continuous stream of made-up syllables for just two minutes. The infants picked out the 'words' by tracking which syllables tend to follow one another. That's probability calculation, done without a calculator or any visible effort.