Beyond the mother: how the voice of a second figure shapes pre- and postnatal bonding

The first sound a newborn recognizes is the mother’s voice, but the voice of a second caregiver—whether male or female—plays a crucial role in the bonding process and in the child’s neuro-emotional development.

This principle lies at the heart of recent research on prenatal and postnatal bonding, which shows that the consistent vocal presence of a significant figure beyond the mother fosters an early and lasting emotional connection.

Neuroscientist Steven Porges (2011), known for his polyvagal theory of the vagal nervous system, affirms:

“The human voice has a regulatory power over the autonomic nervous system that can calm, reassure, and facilitate emotional attachment in the newborn.”

Similarly, psychologist Marian Diamond (1998) emphasized:

 “Exposure to different voices and sounds helps create a more flexible and resilient brain.”

Prenatal memory and voice recognition

The fetus develops the ability to perceive and store sounds and vocal stimuli as early as the third trimester of pregnancy. The mother’s voice, filtered through the amniotic fluid, is the most familiar and reassuring.

However, the voice of a second caregiver (male or female) can also be recognized and recorded in the fetal nervous system if exposure is regular. This prenatal memory is fundamental: at birth, the newborn recognizes and responds calmly and attentively to these familiar voices, demonstrating that the infant brain builds early connections that influence postnatal behavior.

The brain-shaping effect of voice

One of the most fascinating aspects of voice-mediated bonding concerns its brain-shaping effect: a modulated, familiar voice influences the newborn’s brain waves.

Neuroimaging and EEG studies show that listening to familiar voices induces an increase in alpha and theta waves, which are associated with deep relaxation, attention, and memory. This effect regulates cortical activity, promoting a neurophysiological state favorable to learning and emotional regulation. It also helps establish early neurobiological communication between the newborn and the caregiver. As neuropsychologist Mark Johnson (2019) pointed out:

 “The human voice is not just an acoustic signal, but a complex modulator that shapes brain activity and the emotional responses of the developing child.”

The voice of the second caregiver: emotional stimulation and regulation

The male voice or the voice of a second caregiver has acoustic characteristics different from the mother’s, offering the newborn varied vocal stimulation that enriches the sensory repertoire and fosters neuro-emotional adaptation. The consistent presence of this voice helps modulate the child’s stress response, reducing heart rate and supporting autonomic nervous system regulation through mechanisms of emotional co-regulation.

The vocal diversity provided by multiple caregivers creates a rich environment of emotional stimuli, facilitating the development of emotional regulation. In this context, the newborn experiences a stronger sense of security and belonging—key elements for healthy, harmonious growth. Recognition and familiarity with the second caregiver’s voice strengthen the formation of an emotional bond that goes beyond immediate physical contact. Speaking, singing, or simply being vocally present helps the newborn better tolerate environmental stimuli and develop greater emotional self-regulation.

Finally, vocal contact, when combined with practices such as skin-to-skin, amplifies the physiological benefits on the cardiovascular and respiratory systems, contributing to the child’s overall well-being in the first months of life.

Practical applications

Regular prenatal vocal exposure: the second caregiver can dedicate daily moments to speaking or singing to the maternal belly with a calm, modulated voice. This stimulates prenatal memory and provides reassuring familiarity at birth.

Active participation in medical check-ups: being present during obstetric visits or prenatal classes strengthens the emotional connection with the baby and encourages conscious involvement in future care.

Postnatal vocal contact combined with skin-to-skin: during skin-to-skin, the second caregiver can speak or sing, creating a sensory synergy that enhances neurovegetative regulation and cardio-respiratory stability.

Daily care routines: talking to the newborn during ordinary moments (diaper change, bath, falling asleep) strengthens emotional presence and improves emotional regulation during critical moments.

Environmental stimulus regulation: the second caregiver can adjust light and noise, integrating reassuring vocal stimuli to create an environment favorable to the child’s neurophysiological well-being.

Conclusions

Prenatal and postnatal bonding mediated by the voice of a second caregiver plays a crucial role in supporting neuro-emotional development and strengthening early emotional attachment.

The voice is one of the first and most powerful ways through which the nervous system regulates emotion and promotes social connection. The brain-shaping effect further demonstrates that the familiar voice modulates cortical activity in ways that optimize emotional regulation and learning ability in the newborn.

Through targeted vocal practices, combined with physical contact, it is possible to optimize the newborn’s experience of security and well-being, fostering a balanced and supportive family environment.