More than twenty years ago I remember reading that fetuses can learn to recognize their mothers and father’s voices and then respond to those voices as newborns. I thought… well maybe… but it seemed to me that voices from outside of the womb would sound muffled from inside. Of course, I don’t remember my in utero experience so I don’t really know how words sound.

Over the years though, scientists have continued to examine how and what babies learn before they are born.

A recent study by researchers at the University of Helsinki in Finland have determined that fetuses not only hear and recognize voices but they can become familiar with different words and different pitches used when saying those words.

The study involved 33 moms-to-be, and examined their babies after birth. While pregnant, 17 mothers listened at a loud volume to a CD with (2), four-minute sequences of the made-up words “tatata” or “tatota.” The words were said with several different pitches. The moms-to-be listened to the recordings beginning at 29 weeks of pregnancy -about 7 months along- until birth. They heard them around 50 to 71 times.

Following birth, researchers tested the babies for normal hearing and then performed an electroencephalograph (EEG) brain scan to see if the newborns would respond to the made-up words and different pitches. And sure enough, the brain scans showed increased activity from the babies who had been listening to the CD in utero when the words were played to them after birth. Not only did they respond to the words, but also seemed to recognize the different pitches used when they heard them.  

The babies born to the mothers who had not listened to the CDs while pregnant showed little reaction to the words or pitches.

 “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.”

Some experts believe the finding shows that not only can a third-trimester fetus hear and recognize voices; he or she can also detect subtle changes and process complex information.

“Interestingly, this prenatal exposure also helped the newborns to detect changes which they were not exposed to: the infants who have received additional prenatal stimulation could also detect loudness changes in pseudo words but the unexposed infants could not,” Partanen says.

“However, both groups did have responses to vowel changes (which are very common in Finnish, and which newborns have been many time previously been shown to be capable of).”

You may be wondering why is it even important that scientists know if fetuses can recognize voices or words.  Partanen says because sounds heard in utero may shape the developing human brain in ways that affect speech and language development after birth.

“The better we know how the fetus’ brain works, the more we’ll know about early development of language,” Partanen says. “If we know better how language develops very early, we may one day be able to develop very early interventions [for babies with abnormal development].” 

An abstract for the Finnish study is published on the Proceedings of the National Academy of Sciences website.

Does talking and singing to your baby before it’s born actually stimulate his or her brain activity and increase language learning? Some experts say definitely yes, others say it has no impact. But really, most moms and dads enjoy baby bump bonding whether it’s productive or not. And who knows, maybe your pre-born hears you loud and clear. 

Source: Meghan Holohan, http://www.nbcnews.com/health/unborn-babies-are-hearing-you-loud-clear-8C11005474