“A month before they are born, fetuses carried by American mothers-to-be can distinguish between someone speaking to them in English and Japanese.”

According to a study done at the University of Kansas by a group of researchers from their Department of Linguistics, in-utero language discrimination was shown.

Previous research has demonstrated that babies only a few days old respond to the rhythmic differences between languages by exhibiting changes in their rate of sucking on a pacifier.

This early differentiation caused researchers to wonder when a child’s “sensitivity to the rhythmic properties of language emerges.”

Could this happen before the baby is born?

Previous research investigations have documented that fetuses can hear things, like speech.

• They used ultrasound and monitored the fetuses’ heartbeats to determine that.

Current imaging equipment has evolved.

• It can detect changes in heartbeats, breathing and other body movements.

Considering that the first study used different speakers for the two languages, linguists wanted to know if fetuses can distinguish between speech sounds by the same person.

The auditory system is the first to develop in the fetus. During its rapid development and forming of networks, the fetus’ auditory cortex in the brain gets stimulation from the multiplicity of sound coming from the mother:

• Her heartbeats
• Her gut sounds
• Her voice
• External sounds in her environment

This makes the intrauterine environment a noisy place.

How well does the fetus distinguish between the sounds it hears in this clamor?

Recordings were made using one bilingual speaker using English and Japanese. “The fetal heart rates changed when they heard the unfamiliar, rhythmically distinct language (Japanese) after having heard a passage of English speech, while their heart rates did not change when they were presented with a second passage of English instead of a passage in Japanese.”

Considering the very different rhythmic differences between English and Japanese, changes in fetal behavior when listening to recordings by the same bilingual speaker in these languages suggest that language development may very well begin in utero.

You may read the study, which was published in the Journal NeuroReport, here.

Seeing that this current research seems to suggest that fetuses appear to learn more from their prenatal experience with speech than previously believed, what are the implications for subsequent language acquisition?