© 2021 Gwen Dewar, Ph.D., all rights reserved
A mother’s voice has special power. It can provide comfort — and improve outcomes — for babies hospitalized in the NICU. It can shape the way infants process language in the brain. And it can help children cope with pain and stress.
What happens when a baby hears its mother’s voice?
The story begins before birth.
By the last trimester of pregnancy, babies can hear their mothers talking, and they react to what they hear. They wiggle. They move. Their heart rates change.
Moreover, these babies can tell the difference between the voices of their mothers and the voices of strangers. They can even distinguish between their parents’ native language and a foreign tongue (Carvalho et al 2019).
So newborns aren’t clueless about voices. They’ve already had experiences with “listening in.”
And as children grow older, they continue to show a bias for tuning into maternal talk, and they may experience a variety of benefits from listening to mom. Here are the highlights.
Newborns prefer their mothers’ voices
As I explain in my article about the social world of newborns, young infants — just a few days old — can identify their mothers’ voices. And they seem to prefer mom’s voice to the voices of other women.
For example, in one classic study, newborns listened to voices played over a loudspeaker, and their interest waxed and waned depending on whom they heard. When it was the voice of their own mother, they were more attentive. They spent more time turning their heads in the direction of the loudspeaker (e.g., DeCasper AJ and Fifer 1980).
Listening to a mother’s voice can improve outcomes among hospitalized newborns
When babies are born preterm, they are at higher risk for medical problems. So many preterm infants end up spending time in neonatal intensive care units, and medical providers are always looking for ways to help these babies thrive.
One safe bet? Exposing babies to their mothers’ voices. As researchers note in a recent review of the evidence, listening to mom may increase a preterm infant’s autonomic stability, and promote healthy weight gain (Williamson and McGrath 20219).
I haven’t found any similar research regarding health outcomes in full-term babies. But I’ve seen studies suggesting that maternal voices can help all sorts of hospitalized infants — preterm and full-term — cope with the pain of medical procedures.
For instance, in recent experiments, researchers found that babies showed less intense distressed responses to painful procedures (like blood draws) when they were allowed to listen to their mothers talking (Chen et al 2021; Azarmnejad et al 2017).
A mother’s voice can also have special effects on language processing
Parents often adopt a distinctive vocal register when speaking to babies. Their voices become more musical, more exaggerated in tone. They speak at a slower pace, and repeat certain key words.
This “infant-directed speech” captures a baby’s attention, and it helps us convey our emotions. It may even accelerate the pace at which infants learn language. Read more about it in my article, “Baby Talk 101: How infant-directed speech helps babies learn language.”
But babies hear infant-directed speech from many sources, including friendly strangers. Is there anything distinctive — anything “extra” — about a mother’s infant-directed speech?
It seems so. If you compare the effects of a mother’s voice with the effects of an unfamiliar woman’s voice, babies don’t respond the same way — even if both individuals are using “infant-directed speech,” and saying exactly the same words.
For example, in a recent study, researchers used brain imaging technology (near infrared spectroscopy) to see how infant brains process the speech sounds they hear.
It’s a painless procedure. Each infant — a newborn — wore a little electrode cap. Then the baby heard a series of audio recordings.
All of the recordings featured a woman talking in the “infant-directed” style, and reading from a standard script. But the identity of the woman varied from trial to trial. Sometimes it was a stranger. On other occasions, it was the baby’s own mother. And it made a difference.
When newborns listened to their own mothers (as opposed to strangers), they experienced heightened activity in the left and right frontotemporal networks — brain networks that connect areas associated with language and voice processing (Uchida-Ota et al 2019).
Does this mean that babies are more likely to learn words if they hear them spoken by their own mothers?
Another experiment supports this idea.
Researchers invented some nonsense words, words that no child would have ever heard before. Then they provided two-year-olds with opportunities to learn these fanciful terms.
In some trials, the children were introduced to a new word by their own mother. In other trials, the children heard a word spoken by a friendly, but unfamiliar, woman.
What was the outcome? The toddlers learned new words more easily when they heard the words spoken by mom.
It was true in the context of live interactions (where the children could see and interact with the women). It was also true when kids were limited to hearing voices alone (van Rooijen et al 2019).
A mother’s voice continues to have an impact throughout childhood
So far, we’ve been talking about babies. But there’s evidence that older children, too, respond in distinctive ways to a mother’s voice.
For example, in one study, researchers presented 7- and 8-year-olds with the pre-recorded voices of different women, including the children’s own mothers.
The kids were asked the rate the intensity of the emotions they heard, and their answers varied: Kids were more likely to rate their own mothers’ voices as being more intensely angry or happy (Stoop et al 2020).
It seems they were reading things into their mother’s voices that they didn’t notice in the voices of strangers.
Then we’ve got the evidence from another brain imaging study — this time using a technique called functional magnetic resonance imaging, or fMRI.
Daniel Abrams and his colleagues scanned the brains of 24 healthy school children as the kids listened to audio recordings — playbacks of different women repeating nonsense words.
The audio clips were very brief, some lasting less than a second. But the children easily identified the voices of their own mothers, and when they heard their own mothers, their brains switched into high gear.
Compared with reactions to non-maternal voices, the children’s brains showed greater engagement in a wide swath of the brain, including brain regions specializing in auditory processing, emotion processing, reward processing, face-processing, and self-reflection.
It revealed a heightened sensitivity for maternal voices, and there was a link with social communication skills: The most socially savvy children didn’t just show high levels of brain activity in response to their own mother’s voices. They also experienced greater connectivity between the brain regions in question.
In effect, the researchers could look at brain scans and infer which kids had the strongest social communication skills. Kids with the most “mother-biased” brain activity were the most socially adept (Abrams et al 2016).
What else? A mother’s voice can lower stress hormone levels, and trigger a surge of oxytocin.
To see what I mean, consider this experiment led by Leslie Seltzer. Her research team asked a group of young girls—aged 7 to 12—to perform a stressful academic task in front of a live audience.
It’s the sort of thing that makes cortisol levels rise, and that’s normal. But what’s not so healthy is when a child continues to experience high cortisol levels after the stressful event has passed. Ideally, we want to see kids snap back to their pre-stressor status quo.
So Selzer’s team wanted to see if mothers could facilitate the stress recovery process, and they tested for this by randomly assigning each girl to experience one of three, post-stressor conditions:
- the control condition, in which a girl would watch a “neutral ” movie (i.e., one that was neither stressful nor soothing) for 75 minutes;
- the direct contact condition, in which a girl would interact with her mother for 15 minutes, face-to-face, and then spend an additional 60 minutes watching the neutral movie; or
- the voice-only condition, in which a girl would talk to her mother on the phone for 15 minutes, and then watch 60 minutes of that movie.
The researchers monitored changes in the girls’ hormonal levels throughout, focusing on cortisol (the stress hormone) and oxytocin. Oxtocin is a hormone that promotes feelings of social connectedness. It also helps calm us down.
What patterns did the researchers see?
For all girls, there was a sharp spike in cortisol levels immediately after their public performance.
But the girls who got to spend time with their moms—either in person or on the phone—experienced the fastest recovery. Their cortisol levels returned to baseline within 30 minutes. And their oxytocin levels got a boost that lasted for at least one hour.
The girls who didn’t interact with their mothers at all? Their cortisol levels continued to rise after the stress test. And they didn’t experience any boost in oxytocin.
So mothers delivered some pretty dramatic benefits to their children, and they were capable of doing so without even being physically present. They could improve their children’s stress response by using their voices alone.
Are mothers the only people who can produce these effects?
Surely not. Mothers’ voices affect children because mothers play such an important role in children’s lives. When other individuals play important roles, they, too, may have an influence.
Consider, for example, what happens to you, as an adult, when you talk with a friend.
A friendly talk lifts your mood. It makes you feel more socially-connected and secure.
And — just as we saw in the case of Leslie Seltzer’s experiment on young girls — your conversation may trigger measurable changes in your brain chemistry.
In experiments on adults, people who engaged in conversations with friends experienced immediate reductions in cortisol. They also experienced a surge of oxytocin (Djalovsky et al 2021).
So while there may be a kind of magic in a mother’s voice, it isn’t an exclusive form of magic. We’re probably affected by the voices of any people who are near and dear to us, in one way or another.
Still, it’s undeniable that mothers are a very big deal. For most babies, they represent the first, most fundamental attachment figure in their young lives. As we’ve noted, it starts even before birth.
And the nature of this primal relationship helps set the pattern for other relationships. When babies feel securely attached to their mothers, it bodes well for their ability to form healthy attachments to others. When babies aren’t securely attached, they may struggle.
Which brings me to my final point: The effects of a mother’s voice aren’t always good.
Children — even babies — can detect stress and anger in our voices. And that can have adverse consequences. For instance, if a child is exposed to frequent conflict — overhearing angry arguments — it could lead to developmental changes in the stress response system.
So mothers (and other caregivers) need to be aware of the negative impact our voices can have.
To learn more about the effects of warm, positive social interactions on children, check out these Parenting Science articles:
- Secure attachment relationships protect children from stress
- Oxytocin affects social bonds and our responses to toxic stress
- Positive parenting tips: Getting better results through humor, empathy, and diplomacy
For advice about coping with stress, see my articles:
- Stress in babies: How to keep babies calm, happy, and emotionally healthy
- Parenting Stress: 12 evidence-based tips for making life better
And for insights into the effects that our negative emotions can have on children, see these articles:
- Can babies sense stress in others? Yes, they can!
- Can babies tell when parents are fighting?
- Treating postpartum depression benefits babies
Abrams et al 2016. Neural circuits underlying mother’s voice perception predict social communication abilities in children. Proc Natl Acad Sci U S A. 113(22):6295-300.
Azarmnejad E, Sarhangi F, Javadi M, Rejeh N, Amirsalari S, Tadrisi SD. 2017. The effectiveness of familiar auditory stimulus on hospitalized neonates’ physiologic responses to procedural pain. Int J Nurs Pract. 23(3)
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Chen Y, Li Y, Sun J, Han D, Feng S, Zhang X. 2021. The Effect of Maternal Voice on Venipuncture Induced Pain in Neonates: A Randomized Study. Pain Manag Nurs. S1524-9042(21)00015-12
Djalovski A, Kinreich S, Zagoory-Sharon O, and Feldman R. 2021. Social dialogue triggers biobehavioral synchrony of partners’ endocrine response via sex-specific, hormone-specific, attachment-specific mechanisms. Sci Rep. 11(1):12421.
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Selzter LJ, Ziegler TE, and Pollack SD. 2010. Social vocalizations can release oxytocin in humans. Proc Biol Sci. 277(1694):2661-6.
Stoop TB, Moriarty PM, Wolf R, Gilmore RO, Perez-Edgar K, Scherf KS, Vigeant MC, Cole PM. 2020. I know that voice! Mothers’ voices influence children’s perceptions of emotional intensity. J Exp Child Psychol. 2020 Nov;199:104907.
van Rooijen R, Bekkers E, and Junge C. 2019. Beneficial effects of the mother’s voice on infants’ novel word learning Infancy. 24(6):838-856
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Content last modified 8/2021
title image of baby staring at mother while she talks on the phone by Galina Zhigalova / istock
image of infant in NICU by istock mvaligursky / istock
image of mother gazing in her baby’s eyes, on bed, by Prostock Studio / istock
image of young girl listening with ear phones, eyes closed, by globalmoments / istock
image of little boy cheerfully talking to his father by Treetree2016 / shutterstock