The speech sounds that a baby hears before birth “pave the way” for subsequent language learning.
The baby begins to perceive sounds (music, mother’s voice) during the 27th week of fetal development. This process corresponds to the formation of connections between neurons, which then can be detected in infants by changing the electrical activity of the brain in response to different sound stimuli.
Minna Huotilainen from the University of Helsinki and her colleagues have conducted an experiment, during which the mothers listened to the repeated reproduction of a pseudo-word “ta-ta-ta” during the 29th week of pregnancy. From time to time, the scientists replaced the middle syllable to “to” or changed the pitch of this syllable.
A few days after birth, the scientists reproduced the same pseudo-words to the babies. The words had the same phonetic variations as well as some new ones: changes in the intensity or duration of the vowel in the middle syllable. In this case, the scientists recorded the activity of neurons in the babies’ brain. They did the same thing with the control group of the babies who had heard only the live speech of the surrounding people before their birth, but no special pseudo-words.
The study confirmed the formation of neural connections in the brain in infants in response to pseudo-words that they had heard in the womb. Best of all, the babies “learned” pseudo-words with variations in pitch as the latter were not typical of their native Finnish language. They also recognized changes in the intensity and duration of vowels better than the control group, which indicates the babies’ ability to generalize the acquired skills.
Thus, the perception of speech in the womb prepares the baby for language acquisition after birth, and noise, on the other hand, can badly affect the development of the baby’s nervous system.