Newborn brains recognize foreign languages heard in the womb before birth

Sounds heard in the womb activate the same brain areas used for the mother tongue: this is shown by a Canadian study

Even in the womb, fetuses begin to recognize the sounds of human language, distinguishing between familiar and unfamiliar tongues. This has been demonstrated by research conducted at the Université de Montréal, which directly measured the brain activity of newborns just days after birth. According to the researchers, as little as ten minutes a day of listening, for a few weeks, can influence the development of the brain’s language areas.

The study shows for the first time, using brain imaging techniques, that newborns “remember” the languages they heard in the womb. And they do so selectively: they respond with greater neural activation to languages they were exposed to during pregnancy, even if these differ from the language spoken at home.

The study

The Canadian researchers involved 60 French-speaking pregnant women. Starting from the 35th week, some of them had their fetuses listen to short stories in French and in a very different foreign language — either Hebrew or German — using headphones placed on the abdomen. The chosen languages had sound structures and rhythms different from French: an important variable for understanding how the brain distinguishes and memorizes sounds.

Each woman played the recordings about 25 times before delivery. Then, within three days after birth, the newborns were exposed to the same stories in three languages: French, the foreign language already heard, and a third new language, never heard before.

During listening, the newborns wore a device called fNIRS (functional near-infrared spectroscopy), which monitors brain activity through infrared light sensors. It’s a non-invasive technology, already used clinically to observe brain responses in the first days of life.

Result: the newborns activated the same brain area — the left temporal cortex — when they heard both French and the familiar foreign language. In contrast, when faced with the new language, the brain response was weaker and more dispersed, indicating that language had not been internalized.

The fetal brain is already sensitive to sounds

The study confirms what has long been suspected: fetuses are able to recognize sounds even before birth. Previous studies, based on behavioral signals such as head movement or sucking rhythm, had already suggested that newborns prefer their mother tongue. But this is the first time that the effect has been observed directly at the brain level.

According to neuropsychologist Anne Gallagher, who led the research, we cannot speak of true language learning during gestation. However, the brain begins to familiarize itself with the rhythmic and sound structures of language, and this early exposure shapes the organization of neural networks involved in language comprehension.

In the last trimester, the fetus’s auditory system is already developed. Although high-frequency sounds are attenuated by the mother’s body, low frequencies (below 400 Hz) pass through more easily. This is why fetuses respond better to low tones, such as those of the human voice or music.

“This tells us that the brain’s language networks are very flexible, but also vulnerable,” Gallagher explained. “A positive sound environment can influence them beneficially. But it’s reasonable to think that a negative environment could also leave a mark.”

No, you’re not raising a bilingual baby in the womb

The researchers clarified that this is not a method for teaching a language to newborns before birth, nor a program to make them bilingual. Rather, the purpose of this study is to understand how human language competence emerges, and how children with language or neurological difficulties can be supported from the very first days of life, as Gallagher emphasized:

We’re not yet ready for clinical applications, but in the future this line of research could offer useful tools to support children with developmental disorders.

In any case, this study changes the way we think about the newborn brain. It’s not a blank slate, but an already active network, which began to form weeks before delivery, listening to the world — or at least its sounds — from inside the womb.

Source: Nature Communications Biology