Hearing Mom’s Voice Helps Preemie Brains Grow

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23 Jul 2009, Creil, France --- Premature Baby.
Photo: BSIP/Amelie Benoist/Corbis

The first sounds we ever hear are the voice and heartbeat of our mothers, and there’s some evidence to suggest that exposure to these early sounds helps babies’ brains develop, particularly the regions associated with hearing and language. If this is true, then premature babies miss out on some crucial weeks of brain development in this area, which may explain why they’re more likely to have problems with hearing and language processing than babies delivered at full term. This week, a fascinating (if small) study published in Proceedings of the National Academy of Sciences puts these two theories together, and the results suggest that artificially creating the sounds a baby hears in utero — specifically, their mom’s voice and heartbeat — promotes growth in preemies’ auditory cortices.

The study was led by Alexandra R. Webb at Brigham and Women’s Hospital in Boston, and over at Science, Emily Underwood has a nice summary of the way Webb and her team conducted their experiment:

To test whether the sounds a fetus would hear in utero can have a positive effect on preemies, [the researchers] asked the parents of 40 such babies at Brigham and Women’s Hospital in Boston for their participation in a monthlong experiment. The researchers asked mothers of half the infants to sing and read “Twinkle, Twinkle, Little Star” and Goodnight Moon in a recording studio and record their heartbeats through a stethoscope connected to a microphone.

The scientist … piped [the sound] for 45-minute sessions totaling 3 hours per day into 21 infants’ incubators, while the other infants received standard care. After 30 days, they compared ultrasound images of the brains of both groups.

After those 30 days, ultrasounds of the babies exposed to the in uterolike auditory environment showed more growth in the areas of their brain associated with hearing and language processing, the researchers report. It’s not clear whether or how this will help these babies as they grow up, but it’s a potentially promising finding for the futures of some of our tiniest babies.