In 2009, researchers analysed the cries of 60 newborns aged three to five days. French babies tended to cry with a rising melody, German babies with a falling one, mirroring the typical intonation of each language. They are echoing the music of speech they heard in the womb during the last weeks of pregnancy.
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.