An excellent TED Talk about how babies distinguish between speech sounds from different languages. The point is that, in this respect, a baby's brain develops before the age of one and then no longer gathers statistics to distinguish between sounds. There are other interesting details too—for example, learning requires a real person; TV and audio won't do.
https://www.ted.com/talks/lang/ru/patricia_kuhl_the_linguistic_genius_of_babies.html
At TEDxRainier, Patricia Kuhl shares astonishing findings about how babies learn one language over another -- by listening to the humans around them and "taking statistics" on the sounds they need to know. Clever lab experiments (and brain scans) show how 6-month-old babies use sophisticated reasoni...