A new study shows that playing recordings of a mother's voice to premature babies in intensive care can strengthen brain connections related to language processing. Researchers found that this simple intervention led to more mature neural pathways in affected infants. The findings suggest potential improvements in long-term language outcomes for preterm children.
Premature babies often face altered brain structures that can lead to language difficulties and impact later communication and academic success. To address this, Katherine Travis at Weill Cornell Medicine in New York and her team conducted the first randomized-controlled trial on using audio recordings of a mother's voice.
The study involved 46 babies born between 24 and 31 weeks of gestation while in neonatal intensive care. Mothers recorded themselves reading extracts from the children's book A Bear Called Paddington. For the intervention group, a 10-minute audio clip was played twice every hour from 10pm to 6am, providing an average of 2.7 additional hours of exposure to the mother's voice each day until the babies' original due dates. The control group received standard care without the recordings.
Once the babies reached term-equivalent age, MRI scans assessed brain network organization and connectivity. Results showed that infants exposed to their mother's voice had stronger and more organized connections in and around the left arcuate fasciculus, a key area for language processing. "Its structure looks more like what we would expect to see in an older or more developmentally advanced infant," Travis said.
The scans indicated increased myelination, the formation of fatty sheaths that insulate nerve fibers for faster signal transmission. "Myelination is a key aspect of healthy brain development, especially in pathways that support communication and learning," Travis added. Prior research links delays in these brain areas to later language and learning challenges, suggesting that targeted voice exposure could mitigate such risks.
Babies prefer their mother's voice due to familiarity from the womb, starting around 24 weeks gestation. "It’s the most familiar and biologically meaningful voice for an infant," Travis noted. However, she emphasized that speech variability from other caregivers might offer similar benefits, an area for future research.
David Edwards at Evelina London Children’s Hospital cautioned that the small sample size requires further validation with additional control groups, including other speech sources. The team plans larger trials and long-term follow-ups to assess if these brain changes translate to improved language skills.
The intervention, published in Frontiers in Human Neuroscience (DOI: 10.3389/fnhum.2025.1673471), is simple and could integrate easily into neonatal care.