Can a language learn before a baby is born?
A growing body of evidence from neuropsychology suggests that the language brain may begin its remarkable wiring even before birth. In a study funded by NSERC (the Natural Sciences and Engineering Research Council of Canada) and conducted with researchers from the Université de Montréal, expectant mothers listened to stories in a foreign language during late pregnancy, and the researchers tracked how these early experiences shaped the newborns’ brain responses to language after birth.
How the study was designed
The team recruited sixty French-speaking pregnant women with normal pregnancies. Each participant was given an MP3 player containing a short story from a contemporary children’s series. Starting around the 35th week of gestation, the mothers listened to the story in French and in a foreign language—either German or Hebrew—using headphones placed on the belly. The choice of languages ensured distinct acoustic and phonological features outside of French while staying within the same individual who would later carry both languages in adulthood. Each mother repeated the listening sessions, on average, about 25 times during the final weeks of pregnancy.
After birth, the newborns were tested within the first hours of life. They heard the same story in three versions: in French, in the foreign language heard prenatally, and in another foreign language they had never heard before. To measure brain activity noninvasively, researchers used functional near-infrared spectroscopy (fNIRS), a technique that monitors changes in blood oxygenation in the cortex — a proxy for neural activation. As one researcher described, the apparatus resembles a soft cap with light sources that gently map brain activity without harming the infant.
What the results show about language networks
The results reveal striking patterns. When babies heard French, their left temporal cortex activated, along with other typical language areas in the left hemisphere, mirroring the adult pattern of language processing. Remarkably, a similar left-hemisphere activation appeared when the babies listened to the foreign language they had been exposed to prenatally, suggesting that prenatal exposure can shape the brain’s language networks in a way that resembles processing of a known language.
In contrast, the completely unfamiliar foreign language elicited much less brain activity and showed little lateralization, indicating that the newborns were already differentiating between familiar (prenatally heard) and unfamiliar linguistic input in a matter of hours after birth.
“We didn’t know whether such a brief exposure would yield measurable effects,” said one of the study’s lead investigators. “But the data clearly show that even a few minutes of daily listening over several weeks can modulate the organization of the language networks.”
Implications for early development and education
These findings underscore the remarkable plasticity of the human brain before birth, particularly for language systems. They suggest that a positive linguistic environment in utero could have measurable impacts on how a baby processes language shortly after birth. Conversely, the study also raises questions about how negative or less enriching environments might influence these neural trajectories.
While the results are compelling, they are not a verdict on long-term outcomes. The researchers emphasize that it is still unknown whether prenatal programming will persist as the child grows. The team is planning follow-up studies to track children over months and years to determine whether early prenatal exposure translates into lasting advantages—or whether effects diminish over time as the brain continues to develop.
What this means for families and researchers
For families, the study invites a broader discussion about how early auditory experiences might support bilingual development. For researchers, it highlights the prenatal period as a critical window of language network formation and a promising domain for exploring interventions that support healthy language outcomes from birth onward.
In sum, the research paints a nuanced picture: language learning may begin before birth, and the brain appears primed to organize and adapt its language networks in response to the linguistic environment experienced in utero. The next chapters will reveal whether these early traces endure and how they interact with subsequent language exposure in early childhood.
