Intriguing new research suggests that your baby is listening closely to what you say—even before she's born. Finnish scientists found that babies in utero not only hear sounds around them, but also can detect subtle differences in words, and recognize those differences after birth.
Researchers at the University of Helsinki in Finland looked at 33 moms-to-be, and examined their babies after birth. While pregnant, 17 mothers listened at a loud volume to a CD with two, four minute sequences of made-up words ("tatata" or "tatota", said several different ways and with different pitches) from week 29 until birth.
The moms and babies heard the nonsense words about 50 to 71 times. Following birth, the researchers tested the all 33 babies for normal hearing and then performed an EEG (electroencephalograph) brain scan to see if the newborns responded differently to the made-up words and different pitches.
Babies who listened to the CD in utero recognized the made-up words and noticed the pitch changes, which the infants who did not hear the CD did not, the researchers found. They could tell because their brain activity picked up when those words were played, while babies who didn't hear the CD in the womb did not react as much.
"We have known that fetuses can learn certain sounds from their environment during pregnancy," Eino Partanen, a doctoral student and lead author on the paper, said via email.
"We can now very easily assess the effects of fetal learning on a very detailed level—like in our study, [we] look at the learning effects to very small changes in the middle of a word."
This paper does more than simply find that babies in utero can hear; it shows that babies can detect subtle changes and process complex information.
Image: Mother and ultrasound picture, via Shutterstock