The auditory environment drives superior temporal sulcus depth in the neonatal period.

Premature birth impacts the development of superior temporal brain regions, including the superior temporal sulcus (STS), a key cortical area for language, voice recognition, and music processing. Using three distinct newborn imaging datasets, we examined the impact of premature birth on STS morphology at term-equivalent age. In the large cohort of the Developing Human Connectome Project (dHCP), we observed a linear relationship between gestational age at birth and STS depth, with earlier birth associated with a shallower STS. We hypothesized that this effect may have resulted from reduced structured auditory stimulation during a critical period of perisylvian network development. To test this hypothesis, we analyzed two additional published cohorts in which preterm neonates were exposed to contrasting auditory environments: either enhanced with structured music or minimized in quiet private rooms. We found that music exposure was associated with deeper STS, while a quieter environment was linked to further STS shallowing. Although the cross-sectional design limits causal inference, our findings suggest that early auditory experience-both in and ex utero-may influence the structural development of temporal brain regions. These results highlight the need to deepen our understanding of environmental influences in order to optimize postnatal settings that support the harmonious development of auditory and language networks.