The Theobiology of a Mother's Voice

The word “science” at its root means “to know” and the word “theology” at its root means “to think about God.” Can we know anything without thinking about God? That is, can we have science without theology? Logically speaking, we state that we cannot, for two main reasons.

  1. We did not create ourselves. Thus, our very existence, our soul: mind, body and spirit, are contingent upon God—who is not contingent. Our knowing, therefore, is contingent upon our existing, and our existing is contingent upon God, who is without contingency.
  2. All knowledge is derived from God, who himself is the source of all knowledge, the Source of all things, visible and invisible. Thus, we cannot say anything about the world without also saying something about God’s immanence in creation. We may say many things about the world, through science, without explicitly saying something about God, but implicitly, we in fact are saying something about God. Perhaps this is what Saint Paul meant when he said, “For since the creation of the world God’s invisible qualities—his eternal power and divine nature—have been clearly seen, being understood from what has been made, so that people are without excuse.” Therefore, when we suppose science, we must presuppose God the Creator, from, through and to whom all creation and science exists. God is always the First Premise in the course of making subsequent premises about the world. This is the ancient way of thinking and knowing about the world, beginning with God, and then logically deducing all science from him, and inducing all science back to him.

In thinking about God, we also turn to the Scriptures, where we learn from these ancient writings that God is a personal God, who forms relationships with mankind, a covenant keeping God, the LORD. We learn that we are God’s image bearers in covenant with him, and that we intimately reflect God’s relationship between the created world and himself. He is the One who is intimately involved with his people in the created world, so much so, that be becomes one with us in humanity, in our very biology, by taking on flesh through the womb of a woman.

Thus, in the created realm, we see God’s immanence in creation and in science, in a relational way, with us, through us, and in us. In fact, we see God’s immanence and relational nature, his bond with us through creation, in the very science of our biology. This framework is what I call a “Relational Theobiology,” which presupposes the following: God’s relational being is witnessed in creation, in the science of our biology, his image bearers in covenant with him, and demonstrated to be true through the incarnation of the LORD Jesus Christ into the world.

Previously, I touched on this idea in discussing fetomaternal microchimerism as expressed in the union of cells between baby and mother during pregnancy in relation to the union between God and man in Jesus Christ. I would like to expand on this theme of a Relational Theobiology by discussing the impact of the mother’s voice on her prenatal child in relation to God’s voice over creation.

Beginning with God in the Scriptures, we see creation as coming forth from the Word of God, the powerful voice of the LORD. Throughout the first chapter of Genesis, we are told, “And God said . . . and there was.” In Scripture we find the voice of God, the LORD, has the power to bring forth substance from nothing, to shape creation, to mold and fashion it, all according to God’s good purpose. The Psalmist explains the power of the voice of the LORD:

The voice of the Lord is over the waters;
The God of glory thunders,
The Lord thunders over the mighty waters.
The voice of the Lord is powerful;
The voice of the Lord is majestic.
The voice of the Lord breaks the cedars;
The Lord breaks in pieces the cedars of Lebanon.

After creating the heavens and the earth (and placing mankind within it), God sent forth his Word to mankind through the prophets. “O earth, earth, earth, hear the Word of the LORD,” says Jeremiah. “Listen and hear my voice; pay attention and hear what I say”, says Isaiah. And, “Incline your ear and come to Me; listen, so that your soul may live.” In the Old Testament, the LORD spoke to Israel by his Word through the prophets; in the New Testament, Gods very Word and voice is made flesh: our LORD Jesus Christ. And the Word become flesh and dwelt among us.” Through the Word-Jesus Christ, we hear the LORDs powerful voice in the flesh. LORD Jesus says, My sheep hear my voice; I know them, and they follow me.”

Our voice is powerful. Saint James, brother of Jesus, speaking about the power of our voice by the tongue says,

And consider ships: Though very large and driven by fierce winds, they are guided by a very small rudder wherever the will of the pilot directs. So too, though the tongue is a small part of the body, it boasts great things. Consider how large a forest a small fire ignites. And the tongue is a fire.

Indeed, the words from our mouth by our tongue are very mighty. By our speech, man has great power for good or evil. Saint James says it perfectly, “With the tongue we praise our LORD and Father, and with it we curse human beings, who have been made in God’s likeness. Out of the same mouth come praise and cursing.” It therefore behooves us to remember the power of our tongue when we speak to one another, so that we might positively impact humanity through the power of our voice.

Before a child is born from her mother’s womb, the voice of her mother has a powerful impact on her prenatal child. The mother’s voice is reported to be the most intense acoustical signal measured in the amniotic environment. Most of us are familiar with research that shows that babies not only recognize their mother’s voice in-utero, but that they prefer it over all over voices. Research has also shown that the mother’s voice has the ability to affect her child’s brain structure, influence her baby’s heart rate and respirations, and is likely a key factor in her child’s development of language.

Prenatal children develop the ability to hear at around 16-18 weeks of gestation in utero. The ability of a baby to hear her mother’s voice vibrating inside the uterus is one way in which bonding occurs. It is wondrous to ponder the first moment that a prenatal child hears her mother’s voice. Hearing her mother’s voice is how she also starts to become familiar with the rhythms of spoken language. This is the voice that will guide and shape her development for the rest of her time in utero, and likely thereafter, if they remain together. Studies show that within two days of birth, infants are able to discriminate between auditory stimuli, such as rhyming children’s stories, that they were exposed to during the last trimester. Attachment is a vehicle for comfort, and from early on in the uterus, the prenatal child hears and becomes familiar with the voices of the people in her life.

When a child is born, because she has heard her mother’s voice as she was growing in the womb, the newborn infant finds comfort in her mother’s voice and turns towards her speech and has the ability to be uniquely soothed and comforted by her mother’s voice. The mother’s voice is preferred by her baby above all other voices. In studies babies exhibit a clear preference for the voice of their mothers on day one of birth. It is this discrimination of the mother’s voice over other voices that is one crucial part in the growing attachment between mom and baby that starts in utero. Jesus says, “The sheep follow him because they know his voice. A stranger they will not follow, but will flee from him, because they do not know the voice of strangers.” So Jesus’s flock discriminates between the Good Shepard’s voice and the voice of others.

The mother’s voice is not just an instrument for mother-child bonding before birth, but it affects the growth and size of her baby’s brain. In 2015, research published in the Proceedings of the National Academy of Sciences examined the effect of recordings of mothers’ voices on premature infants’ brains. This research looked at the change in the auditory cortex for evidence of experience-dependent plasticity of brain development. In the study, which was done at the Brigham and Women’s hospital on premature babies, mothers’ voices were recorded singing and reading. These recordings were then played for hours each day into the incubators of the intervention group of premature babies. The control group of premature babies received standard care, which was without this added voice stimulation from the mother. The findings showed that babies who were exposed to their mothers’ voices had significantly thicker auditory cortices than those in the control group.

Another study showed that a mother can affect the biological functions of her baby such as heart rate and respiratory rate with her voice. Premature babies often have more instability in their body’s ability to regulate essential functions such as heart rate and breathing. But this study showed that preterm infants had less episodes of slow heart rate and altered respiration when they heard recordings of their mother’s voice compared to when they were listening to regular ambient sounds. We may tend to think of functions like heart and respiratory rate as purely biological and autonomous functions of the baby. But a new paradigm of thinking of our biological reality is one that suggests we are more connected to one another than we may think.

To think that the voice of the mother has measurable effects on her baby’s respiration, heart rate, and the size of her child’s brain is to think in terms of a Relational Theobiology: our relationships affect biology because the Trinitarian God is relational in his very nature, which is something we can witness through science in creation. We are just beginning to understand the physiological and biochemical bond between mother and baby, but the impact of the sound of the mother’s voice on the neurobiological development of babies is truly incredible and should not be understated in light of the importance of mother-child bonding.

The fact that a mother’s voice affects the size of her children’s brain by speaking to them or the physiologic functions of breathing or heart rate, points to the beautiful interconnectedness of our humanity, and humanity’s connection with God. Consider when Mary sings to the LORD Jesus in her womb; we can only imagine that this was not the last time she sang to her Son who is our LORD. We can infer that baby Jesus was physiologically shaped by his mother’s voice. This is a great mystery of our faith: that our incarnate LORD Jesus, the Word made flesh, the very voice of the LORD, the One through whom the world was formed, was himself physically shaped by his Mother Mary’s voice on earth.

Just as God has created through his Word, so too do mothers help fashion their prenatal children through their word. In this case, the power of a mother’s voice shapes the biology of her baby’s brain. This is because we receive our relational biology from a relational God, whose being is reflected in creation. The voice of the mother can be seen as washing over the child in utero, helping to shape some important aspects of her child’s biological and spiritual nature. This parallels the voice of the LORD, washing over creation, helping to shape matter and give it substance and form. The LORD says in Isaiah 55,

For just as rain and snow fall from heaven and do not return without watering the earth, making it bud and sprout, and providing seed to sow and food to eat, so My word that proceeds from My mouth will not return to Me empty, but it will accomplish what I please, and it will prosper where I send it.

In addition to the mother’s power to affect the development of certain parts of her baby’s brain, heart rate, and breathing, the mother’s voice is likely the instrument by which her baby develops language. In one study, researchers performed electrical recordings of infants’ brains within 24 hours of birth, while the babies were sleeping. The researchers asked the mothers to say the short “a” vowel sound and then repeated the exercise with the female nurse who brought the baby to the lab. When the mother spoke, responses were noted in the left hemisphere of the baby’s brain, in particular, the language processing and motor skills circuit; this is in addition to the right hemisphere, where voice recognition takes place. When the stranger spoke, however, only the voice recognition part of the right hemisphere of the baby’s brain reacted. This suggests that a mother, through her voice, is the primary initiator of language processing in her child.

Language may be the most important tool through which we express ourselves, communicate ideas, and interact with one another as human beings. And as demonstrated in this study, the language of one leads to the development of language in another. The first voice we hear in this life assists us in the development of our own language ability. The mother’s word begets another’s word. To think that God fashioned his creation in a way in which the mother participates in the development of her child’s language formation in the brain may be taken for granted, but is humbling and awe-inspiring as it speaks to a Relational Theobiology.

We can all think of a certain voice that is special to us, the way it rings, the way it rises and falls in a pattern unique to the person who is speaking, and how that voice makes us feel. The voice of our mother, the first voice that we hear in life, the one we turn to and by whom we are comforted, is a reflection of the voice of our Creator who speaks to us and comforts us. One day we will hear the voice of Jesus audibly, and his voice will ring true and beautiful to our ears as we will be hearing the voice of the LORD, our Creator and Redeemer, the Good Shepard, the voice we have been following.

In biology there is a field of study called epigenetics, which is the study of heritable phenotype changes that do not involve alterations in the DNA sequence. The way that genes are expressed are influenced by several factors (some of them environmental) which can lead to changes “around” (epi) the genome that do not include a change to the nucleotide structure itself, but can be passed down to and inherited by other generations. Recent attention has been focused on the in utero environment and how this milieu affects the expression and activity of certain genes that may result in certain behaviors or traits.

Epigenetics has been a focus of interest to perhaps explain findings around intergenerational trauma. One study, for example, conducted in 2016 by Rachel Yehuda of Mount Sinai hospital with her colleagues found that Holocaust survivors and their children both had evidence of methylation on a region of a gene associated with stress, suggesting that the survivors’ trauma was passed onto their offspring. This is quite remarkable. Early life stress in children also has been associated by other studies with abnormal expression of the serotonin transporter gene.

One subset of the field of epigenetics, referred to as “social epigenetics” is now helping us to describe how communication and emotion can be linked to a transmissible, biochemical change. Music for example, sung or played, has been shown, because of the demands it places on the nervous system, to promote brain plasticity, resulting in functional and structural changes in the brain’s biology. Through this branch of science called social epigentics, we are beginning to see how social influences can affect our biology.

We are loved into existence by the Word of God, the LORD Jesus Christ, who spoke life and creation into existence, and came into the world from his Father by the Spirit through his Mother Mary. Today, this same LORD speaks to us, his flock, his children, his Body, the Church, by the same Word, by the same Spirit. Just as God’s children are formed, shaped, and molded by God’s Word, His voice, by the Spirit, so too are a mother’s children likewise shaped by her word, her voice, by her spirit. Just as God the Father’s voice reverberated in creation when He declared, “This is my Son in whom I am well pleased,” so too does a mother’s voice reverberate over her child in her womb.

Our words have power, even the power to impact physical changes in our biology. We should therefore speak as God speaks, sharing in the same Spirit. In our relationships we should speak edifying things into existence, words of truth and love, and where necessary, words of discipline and rebuke by the Spirit. We should speak as God speaks because we bear God’s image in our being and we share in his Spirit. We were formed in the likeness of God, in the likeness of the LORD Jesus Christ, who came into the world by the Spirit who overshadowed the Mother Mary and conceived of a child. This is a witness to the power of a Relational Theobiology: God’s immanence in creation, in our biology, even God’s Son in the world, the LORD Jesus Christ, born from Mary’s womb.

Creation and Scripture both witness about the One God who is relational through his act of creation, and through his union with creation in his Son. God spoke creation into existence by his Word, made a covenant with Abraham by his Word, saved Israel by his Word, and in these last days, his Word became a baby in Mother Mary’s virgin womb. This miraculous fact proclaims a Relational Theobiology: God incarnate in the world. Thus, we cannot think about our biology without thinking about God, the One God who created all things, visible and invisible, and who became one with us in our biological flesh.

We also see this through the redeeming power of God’s Word in creation. How beautiful the LORD’s words to his Father are when Jesus prays, “I do not ask for these only, but also for those who will believe in me through their word, that they may all be one, just as you Father, are in me and I in you, that they also may be in us, so that the world may believe that you have sent me.” Here Jesus is praying about the Church being united with the Father through him. Through “their word” Jesus means the gospel message about himself in the world. Jesus came into the world to reveal God in our very biology, the image of God, and to redeem our created biology from the power of sin and death.

God has given us a voice and words to be able to deeply connect with one another, to communicate, to form relationships, to affect one another, to shape creation, even down to the level of the cell. We see this truth in the power of the mother’s voice over her child, even in her womb. We see this truth in the power of the Word of God, creating the world, and then made flesh in the world, Jesus Christ. Jesus’s words have the power to make alive, to heal our soul: mind, body and spirit. So too have we, the Church, been given Jesus’s words. In Saint Mark’s gospel Jesus said, “Go into all the world and preach the gospel to all creation.”

The great mysterious revelation of the Christian faith is this: the Creator God became a man and spoke to us face to face through his Son Jesus Christ, the LORD. This revelation of God in creation and science is more than Gods immanence; the incarnation of the LORD Jesus Christ is a witness to the transcendent Gods immanence in creation: God was made flesh. Through Jesus Christ, humanity has been created and formed in the image of God and has been given the powerful gift of voice. Indeed, we find that our voice does impact and shape humanity in a powerful way, even at the level of our biology.

Featured Image: Mother and Child, 1898; Source: Wikimedia Commons, PD-Old-100.


Kristin M. Collier

Kristin M. Collier MD, FACP is an assistant professor of internal medicine at the University of Michigan. She currently serves as an associate program director of the internal medicine residency training program at the University of Michigan and is the director of the program's primary care track. She is also the director of the University of Michigan Medical School Program on Health, Spirituality and Religion.

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