Noisy journeys: An investigation of the sound environment in an incubator during ambulance transports

Each year, between 300 and 350 transports are carried out by the Neonatal Transport Team Göteborg in Västra Götaland Region (VGR). The majority of these transports (approximately 80 %) are conducted using road ambulances, and most patients are premature infants born before 37 weeks of gestation. The central nervous system of premature infants is not sufficiently developed, resulting in a reduced ability to self-regulate and selectively limit or inhibit incoming stimuli, thereby increasing their vulnerability to stress and its negative physiological effects. Noise is one of the main stress-inducing stimuli that premature infants are exposed to in the extrauterine environment. Unlike the acoustic environment of the womb, which is characterized by low-frequency background noise where the mother’s voice stands out distinctly, the extrauterine environment in neonatal intensive care units (NICU) or during transport is dominated by unpredictable and highly variable sounds with a broad frequency spectrum. Research has shown that high noise levels can cause serious health effects in premature infants and negatively impact their growth and healing processes. Results from noise measurements conducted during neonatal transports with VGR’s incubator transport ambulance indicate that the transported infants are frequently exposed to noise levels exceeding 70 dB(A), with peak levels surpassing 110 dB(C), which are far above the guidelines for perinatal care established by the American Academy of Pediatrics. This study examines the noise levels in VGR’s incubator transport ambulance as well as the infants’ heart rates during transport. The report also outlines the various guidelines and requirements for noise in environments where neonatal infants receive care and highlights the discrepancies between these standards. The aim of this study is to provide an overview and analysis of the auditory environment to which premature and sick neonatal infants are exposed during ambulance transports in incubator and to serve as a basis for future measures to protect infants from harmful noise during transport.