A mother singing to her baby is such a normal event that most people give the subject little thought. But why do mothers do it, and what can we learn from it? Researcher Shannon de l'Etoile aims to find out.
Singing to babies is something that happens across most cultures and has, quite possibly, been happening for thousands of years. But why?
This is a difficult question to answer, but Shannon de l'Etoile, professor of music therapy at the University of Miami Frost School of Music, FL, has set out to investigate.
Although the impact of music on the developing brain is not fully understood, according to de l'Etoile: "We know from previous research that infants have the innate ability to process music in a sophisticated manner."
We also know that a mother's song to her infant has characteristics that set it apart from other types of singing. For instance, it has a high starting pitch and increased gliding between pitch levels. A mother's song also has sustained vowel sounds and a variety in amplitude not heard in general singing.
The importance of a mother's song
Initially, de l'Etoile set out to compare mother's singing to their babies with other types of interactions.
"I set out to identify infant behaviors in response to live infant-directed singing compared to other common maternal interactions such as reading books and playing with toys. One of the main goals of the research was to clarify the meaning of infant-directed singing as a human behavior and as a means to elicit unique behavioral responses from infants."
Her study also aimed to investigate the role of infant-directed singing in developing the bond between a mother and her child.
To begin, the researcher filmed 70 infants' responses to six different types of interaction:
- Mother singing an assigned song
- A stranger singing an assigned song
- Mother singing a song of her own choice
- Mother reading a book
- Mother playing with a toy
- Mother and infant listening to recorded music.
This investigation found that singing was just as effective as reading a book or playing with a toy at maintaining infant attention. Additionally, singing held the infant's attention much better than recorded music.
The next step was to study the mother's role during the interaction; as de l'Etoile asks, "what did the infant engagement tell us about the mother's role during the interaction?"
To this end, the researcher continued her observations, now including the makeup of the mother's song - its ebbs and flows, its intonation and tonal content. Analyzing the song uncovered a sensitivity in the performance:
"Findings revealed that when infants were engaged during song, their mother's instincts are also on high alert. Intuitively, when infant engagement declined, the mother adjusted her pitch, tempo, or key to stimulate and regulate infant response."
Shannon de l'Etoile
Infant-directed song and postpartum depression
To further understand the mother's ability to change the flow of her song sensitively, the researcher investigated differences when a mother with postpartum depression sang to her infant.
The results, published in the journal Arts in Psychotherapy, showed that this previously noted sensitivity was reduced. De l'Etoile concluded:
"The extraction and analysis of vocal data revealed that mothers with postpartum depression may lack sensitivity and emotional expression in their singing. Although the infants were still engaged during the interaction, the tempo did not change and was somewhat robotic."
She believes that infant-directed singing for mothers with postpartum depression offers a unique two-way interaction. Both mother and child can benefit; the infant receives the stimulation they crave that helps to focus their attention, and the mothers are distracted from the negativity of the emotions associated with depression.
Overall, de l'Etoile sees infant-directed songs as an important interaction between a mother and her child.
"Mothers around the world sing to their infants in remarkably similar ways, and infants prefer these specialized songs," she says. "The tempo and key certainly don't need to be perfect or professional for mothers and infants to interact through song. In fact, infants may be drawn to the personalized tempo and pitch of their mother, which encourage them to direct their gaze toward [her] and ultimately communicate through this gaze."
As research continues, the interactions between mother and child and the importance of each modality will become clearer. For now, mothers can be encouraged that when they sing to their child, they are continuing a practice that is shared globally and stretches back into the mists of time.