If you’re one of those people who put headphones over your pregnant belly, or played foreign languages for your baby in utero, you just might be onto something.
Researchers have found that babies may be able to hear differences in languages a month before they are born.
In a recent study published in NeuroReport, a team of researchers out of the University of Kansas Medical Center used a magnetocardiogram (MCG), a form of non-invasive technology that measures magnetic fields produced by electrical activity in the heart, to study English-speaking women who were eight months pregnant.
A bilingual speaker made recordings in Japanese and English, two rhythmically distinctive languages. These recordings were then played to the fetus. When exposed to the familiar language (English), the fetuses’ heart rates did not change. When they heard Japanese, however—with which they were not familiar—their heart rates increased.
Previous research suggests that language development starts early. Babies a few days old have been shown to be sensitive to rhythmic differences in languages, as measured by changes in babies’ behavior, such as in the rate of sucking on a pacifier.
“This early language discrimination led us to wonder when children’s sensitivity to the rhythmic properties of language emerges, including whether it may, in fact, emerge before birth,” said Utako Minai, associate professor of linguistics and team leader of the study.
“Fetuses can hear things, including speech, in the womb. It’s muffled, like the adults talking in a ‘Peanuts’ cartoon, but the rhythm of the language should be preserved and available for the fetus to hear, even though the speech is muffled.”
A previous study did suggest that fetuses could discriminate between different language rhythm patterns. However, this study presented the two language by two different people, making it unclear whether the fetuses were sensitive to the different languages or the different speakers. This study controlled for that.
Using the one speaker and cutting-edge technology, the researchers replicated the earlier study’s results. “These results suggest that language development may indeed start in utero. Fetuses are tuning their ears to the language they are going to acquire even before they are born, based on the speech signals available to them in utero. Prenatal sensitivity to the rhythmic properties of language may provide children with one of the very first building blocks in acquiring language,” said Minai.
The researchers hope they will be able to apply this finding to other fields. In the meantime, better dust off that Baby Einstein DVD.