Many of us have heard about playing classical music to babies while they are still in the womb or reading stories to babies before they are born. A fascinating new study came out in the Proceedings of the National Academy of Sciences from Dr. Amir Lahav at Harvard Medical School that studied forty very premature infants, born about 2 to 4 months early. For half of the infants, the researchers recorded their mothers' heartbeats and voices to make a recording similar to what the babies' would have heard in the womb. They played these recordings for the infants for 3 hours a day for a month. The other half of the infants in the study heard routine hospital noises as they normally would. At the end of the month, the researchers used ultrasound (similar to the ultrasounds moms get when they are pregnant) to measure the size of the auditory cortex, which is the part of the brain that allows us to process sound. The babies' who heard recordings of their mothers had significantly larger auditory cortices.
The Take Home Message? The study authors conclude that a baby's brain makes changes in response to the environment even when a baby is born prematurely. Maybe in the future, premature babies in the NICU will routinely reap the positive benefits of hearing the sounds of the womb through recordings of their mother's heartbeats and voices.