Classical Latin called the head 'caput'. But in late Latin, 'testa', a clay pot or shell, came to mean 'skull', probably through a familiar image, rather like calling your head your 'noggin' in English. That word became the French 'tête'. The horse met the same fate: French 'cheval' comes from 'caballus', a nag, while the noble 'equus' survives only in learned words such as 'equestrian'.
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.