Avon comes from a Brittonic word that simply meant 'river', so 'River Avon' amounts to 'River River'. This kind of redundancy is common when a name passes from one language to another. 'Sahara' comes from the Arabic ṣaḥrāʾ, 'desert', making the Sahara Desert the 'Desert Desert'. And in Los Angeles, the La Brea Tar Pits are, word for word, 'the the tar tar pits'.
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.