In the 19th century, Paris slang used 'largonji': replace a word's first consonant with an l, move that consonant to the end and sometimes add a suffix. Paris butchers made it their jargon, 'louchébem', with 'boucher', butcher, becoming 'loucherbem'. From 'fou', crazy, came 'louf', then 'loufoque', recorded by 1873 and now everyday French for zany. 'En loucedé', on the sly, is 'en douce' put through the same grinder.
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.