Women are continuously encouraged to speak to their babies when pregnant, and they should keep it up.
A new study shows that the sound of a mother's voice, and also her heartbeat, stimulates growth in the hearing center of a baby's brain.
As reported in the New York Times, researchers at Brigham and Women’s Hospital in Boston studied 40 babies born eight to 15 weeks prematurely and confined to incubators, thereby spending limited time with their mothers. Half the babies were exposed to the sounds of their mothers’ voices and heartbeats for three extra hours every day using tiny speakers placed inside their incubator. The other half did not receive additional exposure to their mothers' sounds.
Thirty days later, the babies that heard the additional sounds had a significantly larger auditory cortex than those who didn't hear recordings of their mother's voice and heartbeat.
"Preemies born this early are basically fetuses that happen to be out there by accident," Amir Lahav, an assistant professor of pediatrics at Harvard Medical School and senior author of the study, told the Times. This suggests that a mother's voice and heartbeat offer auditory benefits to an in-utero fetus.
Published in Proceedings of the National Academy of Sciences, the study's findings could help guide how to best care for premature babies, who often suffer from developmental and cognitive disabilities.
And while it's common for women to talk to their pregnant bellies as a way to bond with their child, now there's even more reason to get chatty with that baby bump.