Adopted in the early 1920s for radio communication, the distress call 'Mayday' is an English spelling of French 'm'aider', short for 'venez m'aider!', 'come and help me!'. The 1927 International Radiotelegraph Convention made it official. The lower-level urgency call, 'pan-pan', is also thought to come from French 'panne', breakdown. Pilots and sailors call for help in French, often without realising it.
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.