Mom's voice boosts language-center development in preemies' brains, study finds

Hearing the sound of their mother's voice promotes development of language pathways in a premature baby's brain, according to a new  study.

During the study, which is published in Frontiers in Human Neuroscience, hospitalized preemies regularly heard recordings of their mothers reading to them. At the end of the study, MRI brain scans showed that a key language pathway was more mature than that of preemies in a control group who did not hear the recordings. It is the first randomized controlled trial of such an intervention in early development.

This is the first causal evidence that a speech experience is contributing to brain development at this very young age.

Premature babies—born at least three weeks early—often spend weeks or months in the hospital, typically going home around their original due dates. During hospitalization, they hear less maternal speech than if they had continued to develop in utero.

Parents can't usually stay at the hospital around the clock; they may have older children to care for or jobs they must return to, for example. Preemies are at risk for language delays, and scientists have suspected that reduced early-life exposure to the sounds of speech contributes to the problem.

The researchers decided to boost preemies' exposure to their mom's voices during hospitalization. They did this by playing recordings of the mothers speaking, a total of two hours and 40 minutes a day, for a few weeks at the end of the babies' hospital stays.

Babies were exposed to this intervention for a relatively short time. In spite of that, researchers saw very measurable differences in their language tracts. It's powerful that something fairly small seems to make a big difference.

Part 1

Fetal hearing begins to develop a little more than halfway through pregnancy, around 24 weeks into what is normally a 40-week gestation period. As the fetus grows, the uterus expands and the uterine wall thins.

Late in pregnancy, more sounds, including the mother's conversations, reach the fetus. At birth, full-term newborns recognize their mother's voice and prefer the sounds of their parents' native language to other languages, prior research has shown.

These factors suggest that listening to Mom's voice contributes to brain maturation in the latter half of a full-term pregnancy.

So in their work the researchers realized that by supplementing the sounds that premature babies hear in the hospital so they resemble what they would have heard in the womb, they had a unique opportunity to possibly improve brain development at this stage of life.

 Listening to Mom in the Neonatal Intensive Care Unit: A randomized trial of increased maternal speech exposure on white matter connectivity in infants born preterm, Frontiers in Human Neuroscience (2025). DOI: 10.3389/fnhum.2025.1673471

Part 2

Men’s brains shrink more with age
Men’s brains shrink more as they age than women’s brains do, which could scupper the theory that age-related brain changes explain why women are more frequently diagnosed with Alzheimer’s disease than men. Using more than 12,500 brain scans from 4,726 people, researchers found that men experienced a greater reduction in volume across more regions of the brain over time than women did. This suggests that sex differences in brain volume don’t play a part in the development of Alzheimer’s, but “just looking at age-related changes in brain atrophy is unlikely to explain the complexities behind [the disease]”, say neurophysiologists.

 Proceedings of the National Academy of Sciences paper

https://www.pnas.org/doi/10.1073/pnas.2510486122

https://www.nature.com/articles/d41586-025-03353-5?utm_source=Live+...