Researchers have known for 30 years that babies start learning from hearing their mothers talk while still inside the womb … previous studies have shown that fetuses seem to recognize musical melodies.
But a new study co-authored by researchers in the United States and Sweden shows that babies start learning basic units of language — vowels — from about
30 weeks’ gestation on (unborn babies’ hearing mechanisms are fully developed by 30 weeks).
The team of researchers tested 40 infants in Tacoma, WA, and another 40 in Stockholm, Sweden. The babies were from a few hours old to three days of age; half were male and half female.
Researchers placed computer-wired pacifiers inside the infants’ mouths, to measure how long they sucked after hearing a sound, and whether or not they stopped sucking. Each suck produced a new recorded sound, either in the mother’s native tongue, or in a foreign language. Half of the babies listened to sounds in their mothers’ language, and half of them heard sounds in a foreign language.
In both countries, babies who heard foreign language sounds continued sucking and sucked longer overall than babies who heard sounds in their mothers’ native language. When babies continued sucking after hearing a sound, it indicated that they were not interested in the sound they had just heard, whereas if they stopped sucking, it showed that they were interested in the sound.
Babies heard, and were able to distinguish, 17 vowels, either in their mother’s language, or in a foreign language. Vowels were chosen for the tests because they are prominent in speech, and researchers believe they would have stood out, even against the background noises inside the womb.
Earlier studies had focused on prenatal learning of sentences or phrases; but this was the first study to show that babies in the uterus learn small units of speech that are not presented in the context of other factors such as melody or rhythm that would make recognition easier.
“This is the first study that shows fetuses learn prenatally about the particular speech sounds of a mother’s language,” said Christine Moon, lead author and professor of psychology at Pacific Lutheran University in Tacoma, WA.
“The mother has first dibs on influencing the child’s brain,” said study co-author Patricia Kuhl, co-director of the Institute for Learning and Brain Sciences at the University of Washington.
The study will be published in the February, 2013 issue of the journal Acta Paediatrica, a peer-reviewed medical journal in the field of pediatrics.
By Jamell Andrews