I was pumping breast milk for my premature twins when one of them, my tiny seven-day-old daughter, began to cry. She and her brother were born by emergency cesarean section eight weeks before their due date and had spent their days and nights since in incubators at the hospital’s neonatal intensive care unit, fed by tubes and connected to beeping monitors that tracked their every breath and heartbeat. My son slept peacefully much of the time, but my daughter often kicked and shrieked. This time when she cried, I put my arm through the porthole in her incubator, held her hands over her chest, and began to sing. Within a minute, she too was quiet and calm.
I was entranced. I had not known that my singing voice could have such a soothing effect, even though the developing fetus can hear her mother’s heartbeat at 16 weeks and can later recognize her voice in utero. Thereafter, I sang to my babies every day during their two-month stay in intensive care, usually a medley of English and Hebrew folksongs and lullabies. A recent study now shows that lullabies and other forms of rhythmic music therapy can have profound physiological effects on preemies: lowering heart rate, increasing caloric intake, and improving sucking behavior. Singing also decreases parental stress.
Joanne Loewy, director of the Louis Armstrong Center for Music and Medicine at Beth Israel Medical Center in New York City, conducted a trial of three forms of live music therapy on 272 premature babies at 11 hospitals throughout the United States. The musical interventions took three forms: lullabies (chosen by the parents as “important to their cultural heritage,” or the nursery rhyme Twinkle, Twinkle, Little Star), and two instruments designed to replicate womb sounds. One instrument, the Remo ocean disc, contains numerous small metal beads and mimics the “whoosh” timbre of the placenta; the other was the gato box, a drum, played with fingers, that replicates the rhythm of the mother’s heartbeat. All three lowered babies’ heart rate, and lullabies increased periods of “quiet-alert” state, in which the infants focus intently with open eyes on people or objects.
The research is reminiscent of the much-vaunted but mostly debunked “Mozart Effect”: the notion that listening to classical music can improve a child’s intelligence. That notion, which inspired an industry of musical CDs and DVDs, was based on a small 1993 study of 36 college students who experienced a sudden improvement in mental paper-folding skills after listening to a Mozart sonata. A new Israeli study shows that listening to Mozart can lower preemie babies’ metabolic rate, causing them to burn fewer calories and gain weight faster. And according to Loewy, the simple, melodious jumps typical of nursery rhymes can have an effect on infant brain development.
“What we’re learning from research on the neonatal population—where we once thought it’s best to let them sleep and leave them alone—is that brain development and the strength of neural pathways can be enhanced through the repetition and simple sequencing of folksongs, which are used from one generation to the next,” Loewy says. Folksongs clearly helped my twins: now two-and-a-half years old and thriving, they sang each other Twinkle, Twinkle, Little Star last night before bedtime.