Premature babies frequently have problems hearing and processing words because the brain regions that process sounds aren’t completely developed at the time of their birth. A new study published in the Feb. 23 online Proceedings of the National Academy of Sciences suggests that recreating a womblike environment by recording a mother’s heartbeat and voice may increase the preemie’s brain growth.
“Even three hours a day of exposure to [to mom’s voice and heartbeat] was enough to give the brain a very good boost in terms of brain development and maturation of the auditory cortex,” senior author Amir Lahav, ScD, PhD, an assistant professor at the Harvard Medical School, told TODAY.
For the study, Lahav and his colleagues looked at 40 premature babies in the neonatal intensive care unit (NICU) at Brigham and Women’s Hospital in Boston. The researchers had the mothers of 21 babies sing “Twinkle, Twinkle, Little Star” and read ”Goodnight Moon” in a recording studio. In addition, they recorded the mothers’ heartbeats using a stethoscope connected to a microphone to mimic what their babies hear in the womb.
The researchers piped the recorded sounds into the 21 infants’ incubators, playing 45-minute sessions four times a day over a 30-day period. The remaining 19 infants received standard care and were exposed to the normal sounds of the NICU.
At the end of the month-long study, the researchers measured the circumference of the babies’ heads and used ultrasound to examine the size of their auditory cortices – the part of the brain that processes sound. Findings showed that the babies who “listened” to their mothers’ heartbeats and voices had larger auditory cortices than those who heard just hospital noises.
“Babies begin to hear at 25 weeks’ gestation and they’re exposed to the mother’s voice and heartbeat,” Lahav explained in a HealthDay article. “If you put them in the incubator for 5 to 6 weeks, you’re actually depriving them of these maternal exposures to the mother’s voice.”
Added Lahav, “The incubator is seemingly a wonderful piece of equipment. But at the same time, it’s like a social cage.”
Lahav acknowledged that more research is needed to determine if babies with larger auditory cortices have improved language skills. Still, he said that the study suggests that even three hours a day of exposure to womblike sounds “may be enough to set the brain on the right development track.” He also advised that parents of premature babies be encouraged to visit their children in the NICU, and to talk and sing to them while they are in the hospital.