Sequoyah, a Cherokee man who could not read any language, had noticed the power of the settlers' 'talking leaves'. After years of trial and error, he completed a syllabary of 85 symbols for Cherokee syllables in 1821. It was so easy to learn that within a few years much of the Cherokee Nation could read, and a bilingual newspaper appeared in 1828.
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.