© 2021 Gwen Dewar, Ph.D., all rights reserved
Music in the womb? It’s become an almost cartoonish cliché of modern pregnancy — a pregnant mother-to-be playing tunes for her unborn baby.
But is this really a thing? Do fetuses actually respond to music? Will they remember any of it later? The short answer is yes.
In the last trimester of pregnancy, babies become increasingly capable of hearing a range of musical tones, and studies confirm that babies react — in the womb — to the sounds they hear. Moreover, if a late-term fetus “overhears” the same melody again and again, it will likely recognize this tune later — when it hears the music as a newborn.
Do such prenatal experiences make children smarter? Should parents make a special effort to expose their babies to music through high-tech gadgets?
There’s no evidence for that, and in fact experts urge parents to avoid certain kinds of music exposure.
For example, they advise against placing earphones or other audio devices directly onto a pregnant woman’s belly. They also warn mothers-to-be to avoid exposing their bodies to loud, deep, booming noises, or to decibel levels that pose a risk to their own hearing.
But the research helps us appreciate that our babies are engaging with the world long before birth. And it should encourage parents to share musical experiences with their babies — both before and after pregnancy.
Here are the details.
At what point during pregnancy can a baby hear music in the womb?
A baby’s sense of hearing doesn’t go “online” all at once. It happens in steps, and every baby develops at his or her own pace. And of course sounds get muffled in the womb — especially sounds at higher frequencies.
So it isn’t a straightforward question to answer — the age at which your baby will be able to hear your favorite tune.
We know that babies can hear some sounds during the second trimester of pregnancy, and by 25 weeks gestation, approximately half of all fetuses are responsive to tones in the range of 100-500 Hz — a range that overlaps with adult speech (Hepper and Shahidullah 1994). So babies might be capable of hearing music — or at least some fragmentary elements of music — that also fall into this range.
But for better listening abilities, we have to wait until babies are bit older — around 30 weeks or more.
For instance, most babies don’t respond to tones as high as 1000 Hz (which is just a smidge lower than “high C” on a keyboard) until at least 30 weeks gestation (Hepper and Shahidullah 1994).
And when researchers presented fetuses with an entire lullaby — as opposed to a few, isolated tones — they found evidence that babies begin paying more attention to music at around 33 weeks gestation (Kisilevsky et al 2004).
Can music be too loud for a baby in the womb?
It’s possible, so we need to be mindful of the potential for harm. For decades, medical experts have recommended the same, cautious approach to prenatal sound exposure (Graven 2000; Kruger et al 2021):
- Don’t attach earphones or any other sound production devices to a pregnant belly.
- Avoid environments where noise levels put your own hearing at risk.
- If you’re listening to lower-frequency sounds, avoid sustained volumes over 65 decibels. A mother’s body muffles the intensity of sound that the baby hears, but not as effectively when sounds are lower or deeper. Music with a loud, pulsing bass line could be hazardous.
How do fetuses respond to music?
That’s a good question. On a superficial level, we know that babies notice when sound — voices or music — filters into the womb. Their heart rates change, and they tend to move around more (e.g., Kisilevsky et al 2010; Gerhard and Abrams 2000; Arabin and Riedewald 1992).
But are babies noticing the contours of music? Are they sensitive to patterns? The specific sequence of notes that they hear?
There’s reason to think so, because studies suggest that newborns may remember music they heard during pregnancy.
Evidence that babies can recognize music they heard during gestation
If a pregnant woman listens to the same melody — again and again — it presents a possibility. Might her fetus become familiar with the music? So much so that the baby will be capable recognizing the tune later — after childbirth?
Decades ago, Peter Hepper tested the idea by observing the responses of newborns to a particular television show theme song.
Some of the babies had gestated with mothers who were fans of the TV program. As fetuses, these babies had heard the theme song many times.
And other babies? Their moms hadn’t watched the show during pregnancy. The theme song was totally unfamiliar to them.
So Hepper played the tune to newborns, and found evidence for fetal memory.
The babies who had “overhead” the theme song during gestation became more alert. Their heart rates slowed, and they stopped moving around.
This reaction was absent when the same infants listened to other, unfamiliar melodies. And it was also absent among the babies who hadn’t been exposed to the TV theme during pregnancy (Hepper 1998).
Intrigued, Hepper conducted a follow-up study, where he monitored fetuses directly via ultrasound.
Once again, he tested babies’ responses to the same TV theme song, and once again, he found a difference. It wasn’t apparent among young fetuses (babies at 30 weeks gestation). But by 37 weeks gestation, infants were behaving differently when they heard familiar (as opposed to unfamiliar) music (Hepper 1991).
Is this conclusive? Not exactly. The studies were small, making it hard to rule out chance effects. But Hepper’s work inspired other research — and the results support the idea that fetuses can learn about music.
For example, in a controlled experiment, researchers created and recorded a unique piano melody, and then assigned pregnant women to play it back to their fetuses, starting at 35 weeks gestation.
The fetuses heard the music twice daily for three weeks only. Then it stopped, with no further music sessions until four weeks after the babies were born.
And that’s when the babies — 25 infants in total — faced the big test: They were brought to a laboratory, where they heard the melody once again. In addition, they listened to a brand-new piece, another piano melody they had never encountered before.
What happened? The researchers monitored the babies’ heart rates, and compared these with the heart rates of 25 infants in a control group. And the contrast was pretty dramatic.
Babies in both groups tended to experience a momentary slow-down in heart rate as they listened to music. But the effect was much larger for infants who listened to music they had heard previously, during gestation (Granier-Deferre et al 2011).
It was as if they recognized the old, “prenatal” music, and found it to be especially calming.
What about responses in the brain?
When babies listen to music, it doesn’t just affect their heart rates. It also stimulates brain activity, and researchers can track changes in this activity by using event-related potentials (ERPs) – small changes in voltage that can be detected by attaching electrodes to an infant’s scalp.
So Eino Partanen and his colleagues used this approach to look for neural differences in the way that newborns respond to music. Do their brains react differently if they hear music they encountered during gestation?
Partanen’s team began their study by asking a dozen pregnant women to follow a specific music-listening regimen, starting at 29 weeks gestation.
Once per day, 5 times per week, the mothers-to-be listened to a specially-prepared, keyboard rendition of the song, “Twinkle, Twinkle, Little Star.”
The babies ended up hearing this tune a lot. Anywhere between 138 and 192 times!
But the prenatal music “lessons” ended immediately before childbirth. And then, as newborns, the babies heard the tune once again — the first time since emerging from the womb.
The researchers recorded the infants’ ERPs as they listened. And they did the same for infants in a control group — newborns who hadn’t been through the special, prenatal regimen.
And the outcome?
There was a clear difference between groups. The babies who had experienced prenatal “training” showed a stronger, more dramatic change in brain activity while listening to the familiar tune.
Moreover, it was a difference that lasted. The researchers tested the infants again at 4 months postpartum, and found that babies with prenatal experience of “Twinkle, Twinkle” continued to show a stronger neural response to it (Partanen et al 2013).
So does listening to music in the womb make babies smarter?
There’s no evidence for that, or for related claims that we can boost intelligence by listening to music after birth. (Read more about it in my article about the so-called Mozart Effect.)
In fact, as I write this, there is no consensus among researchers that prenatal music delivers long-term benefits to babies.
For example, when researchers have examined trends across studies, they haven’t found that prenatal “music therapy” delivers clinically meaningful health benefits to infants (He et al 2021).
Listening to music can reduce stress for the mother, and that’s a good thing. But it’s not yet clear if babies experience any special health effects as the result of being exposed to music in the womb.
Nevertheless, we’ve got reason to think that unborn babies are stimulated by music, and can become familiar with certain tunes. That should encourage us to share music with our unborn infants. To sing. To make music with friends. To listen to music the “old-fashioned” way — by filling the the air with it. Not by piping music into earphones.
And this research should inspire us to regard newborns with additional respect. They aren’t mere “survival machines,” with nothing in their heads but instinctive programming to eat or cry.
On the contrary, they have been paying attention to the social world — the social world of sound — for many weeks before birth. And by the time they meet us face to face, they are ready — and eager — to learn more.
Want to know what else babies are learning before birth? Check out my Parenting Science article, “Prenatal learning: Do pregnancy foods affect babies’ eating habits?”
And for more information about the remarkable abilities of newborns, see these Parenting Science articles:
References: Music in the womb
Arabin B and Riedewald S. 1992. An attempt to quantify characteristics of behavioral states Am J Perinatol 9: 115-119
Gerhardt KJ, Abrams RM. 2000. Fetal exposures to sound and vibroacoustic stimulation. J Perinatol. 20(8 Pt 2):S21-30.
Granier-Deferre C, Bassereau S, Ribeiro A, Jacquet AY, Decasper AJ. 2011. A melodic contour repeatedly experienced by human near-term fetuses elicits a profound cardiac reaction one month after birth. PLoS One. 6(2):e17304.
Graven SN. 2000. Sound and the developing infant in the NICU: conclusions and recommendations for care. J Perinatol. 20(8 Pt 2):S88-93.
He H, Huang J, Zhao X, Li Z. 2021. The effect of prenatal music therapy on fetal and neonatal status: A systematic review and meta-analysis. Complement Ther Med. 60:102756.
Hepper PG. 1988. Fetal “soap” addiction. Lancet 1(8598):1347-8.
Hepper 1991. An Examination of Fetal Learning Before and After Birth. Irish Journal of Psychology 12: 95-107.
Hepper PG and Shahidullah BS. 1994. Development of fetal hearing. Archives of disease in childhood-fetal and neonatal edition 71: F81-F87
James DK, Spencer CJ, Stepsis BW. 2002. Fetal learning: A prospective randomized controlled study. Ultrasound Obstet. Gynecol. 20:431–438.
Kisilevsky BS and Hains SMJ. 2010. Exploring the relationship between fetal heart rate and cognition. Infant Child. Dev. 19:60–75.
Kisilevsky S, Hains SM, Jacquet AY, Granier-Deferre C, Lecanuet JP. 2004. Maturation of fetal responses to music. Dev Sci. 7(5):550-9.
Krueger C, Horesh E, Crossland BA. 2012. Safe sound exposure in the fetus and preterm infant. J Obstet Gynecol Neonatal Nurs. 41(2):166-170.
Partanen E, Kujala T, Tervaniemi M, Huotilainen M. 2013. Prenatal music exposure induces long-term neural effects. PLoS One. 8(10):e78946.
Content of “How do babies respond to music in the womb” last modified 8/21
Title image of pregnant woman at piano by hanamirae / istock
image of ultrasound by Mikail Damkier / shuttestock
image of newborn gazing at mother by chomplearn / shutterstock