Imagine 2 newborn babies in a room. One is French. One is German. And they look pretty much the same as most newborns do. So you don't know which one is which. How then, without meeting the parents, can you know which one is the French one, and which one is the German one?
According to a team of researchers led by Kathleen Wermke of the University of Wurzburg in Germany, you listen to their cries!
This group of scientists recorded and analyzed the cries of 60 healthy newborns ranging in age from three to five days. Half the babies were born into French-speaking families, and the other half were in German-speaking families as they grew in the womb.
And when they were born, their cry melodies were distinctive and different! The French newborns tended to cry with a rising melody contour, while the German tots wailed with a "falling" tone, a signature feature in each language.
This new research, published in the upcoming issue of Current Biology, debunks the assumption that tiny tots cannot vocalize distinctions and differences in language, even if they can perceive those differences.
This also reinforced the idea that limitations to acquiring language at the youngest ages may be more physical than cognitive. To see the full article on this study, go here.
Fascinating, isn't it? 
I was fascinated with this, coming from a German background, though I realise that there will be all kinds of variations across different nationalities. I wonder how a German baby would fare adopted into a French household or vice versa. Would they have difficulties with the very different kind of pronunciation required with the other language.