Though babies speak much later in life, they start listening to sounds much earlier. Babies that are a few hours old can differentiate between sounds of their native language and a foreign language, scientists have discovered. This research study suggests that babies while still in the womb may be tuning into the sounds of the language, much earlier than previously thought.
Sensory and brain mechanisms for hearing are ready by 30 weeks, and the new study indicates that unborn babies are listening to what their mothers are talking during the last 10 weeks of pregnancy. In fact, at birth the babies can demonstrate what they’ve heard.
“The mother has first dibs on influencing the child’s brain,” said Patricia Kuhl, co-author and co-director of the Institute for Learning & Brain Sciences at the University of Washington. “The vowel sounds in her speech are the loudest units and the foetus locks onto them.”
Previously, researchers had studied how newborns are born ready to learn and begin to discriminate between language sounds within the first months of being born, but there was no evidence that language learning had occurred in the womb.
“This is the first study that shows foetuses learn prenatally about the particular speech sounds of a mother’s language,” said Christine Moon, lead author and a professor of psychology at Pacific Lutheran University in Tacoma, Wash. “This study moves the measurable result of experience with speech sounds from six months of age to before birth.”
The results will be published in an upcoming issue of the journal Acta Paediatrica.
Forty infants, about 30 hours old and an equal percentage of girls and boys, were studied in Tacoma and Stockholm, Sweden. While in nursery, the babies listened to vowel sounds in their native tongue and in foreign languages.
Their interest in the sounds was noted by measuring how long they sucked on a pacifier that was wired into a computer measuring the babies’ reaction to the sounds. Longer or shorter sucking for unfamiliar or familiar sounds is evidence for learning, because it indicates that infants can differentiate between the sounds heard in the womb.
In both countries, the babies at birth sucked longer for the foreign language than they did for their native tongue.
The researchers say that infants are keen learners, and discovering how they absorb information could give insights on lifelong learning. “We want to know what magic they put to work in early childhood that adults cannot,” Kuhl said. “We can’t waste that early curiosity.”
Patricial Kuhl has previously studied how babies learn language. Here is a TED video of her previous research