If you’re like most parents, you’re no doubt already convinced that your baby is a genius, whatever his age. But did you know that he began learning language while still in your womb? Or that he’s using an innate statistical ability to do it? New research into why babies learn languages so easily compared with adults is shedding light on the infant brain and the critical role that parents play in language acquisition. 

It’s All About Syllables

Researchers have long known that newborns can tell the difference between languages and even syllables. To see if babies develop those abilities in the womb, scientists measured a dozen premature babies’ neural response to spoken language. They found that the babies could already distinguish between the syllables “ba” and “ga,” and they could tell male and female voices apart, even though their brains were not yet fully formed. The study, which was published in Proceedings of the National Academy of Sciences, suggests that babies’ brains are innately wired to process language. 

Telling different syllables apart is crucial to language acquisition, because babies need to learn which syllables have meaning in their native tongues and which don’t. Human beings produce a total of 800 consonant and vowel sounds, but most languages are built on only about 40 such sounds, which are then mixed and matched to form words. At first, your baby pays attention to all 800 sounds, allowing him to be open to learning any language on the planet, according to a review of the scientific literature in the journal Mind, Brain and Education

Your infant discerns which sounds matter in his native language, or languages, by automatically employing computational areas of his brain to track the statistics on all 800 sounds and to figure which ones are used most often. That’s a lot of math, so it will take your baby six months to a year to ferret out the right syllables. Researchers believe that “parent-ese,” the kind of exaggerated speech that parents all over the world naturally use with their children, helps babies figure out which sounds are relevant because it stresses the important syllables, making it easier for babies to pick up on their frequency, 

Homing in on Sounds

Once he’s found the right syllables, your baby will start to focus only on the sounds needed to understand his native language and will begin ignoring the sounds used in other languages. This self-editing helps him learn to speak, because it allows him to concentrate on the huge task of working with syllables to form words and attach meaning to them. But there’s a downside. As babies pay less attention to nonnative language syllables, they gradually lose the ability to pick up foreign languages, which is why adults have to work so much harder than young children to learn a new language. 

You might be able to keep the language-learning window open longer by exposing your baby to a foreign language, even if it’s not spoken in the home. Research published in the Proceedings of the National Academy of Sciences, found that 9-month-olds who’d participated in a dozen 25-minute sessions with native Mandarin speakers not only learned to distinguish Mandarin syllables but retained that ability for up to 12 days (though how long the results lasted is unknown). 

But don’t bother running out to buy a bunch of language tapes. The babies in the study who were exposed to DVDs of Mandarin speakers, as opposed to experiencing live interactions, didn’t pick up a thing. Researchers think that babies use visual and social cues, like following Mom’s gaze to the pictures in a book she’s reading, to figure out which sounds are important. So bear in mind that every time you chat up your baby, he’s soaking up all kinds of information he needs to decode his language—even if he doesn’t have much to say just yet.