Noise in the NICU: how prevalent is it and is it a problem?

The uterine environment protects the developing fetus from loud and high-frequency sounds, enabling a gradual exposure and learned response to different sounds. For the preterm infant in the neonatal intensive care unit (NICU), this protective environment is lost and replaced by a harsh clinical environment that often exceeds recommended noise levels. There is growing interest in the role of the ex utero environment in promoting normal brain development. This article reviews why the preterm infant is more at risk from excessive or sustained noise, what recommendations exist to limit noise, and avenues for future research in this area.