Hourly sound level exposures for preterm infants in the neonatal intensive care unit

Abstract

Infants born preterm are at greater risk for auditory dysfunction than full-term infants. To better understand and characterize the neonatal intensive care unit (NICU) auditory experience, we sought to examine the sound pressure levels (SPLs) in the NICU and the presence of a circadian pattern of sound level exposure. Data were collected for very preterm infants (born ≤ 32 weeks’ gestation; n = 36) during NICU stay. Audio recordings were collected over 24-hour intervals, three times per week for each subject using a LENA recorder that was adhered to the inside wall of the infant’s incubator or crib. Average hourly SPL values were calculated from the raw recordings. Preliminary analysis indicates that the highest hourly exposures occurred during the hours of 8–9 AM and 8–9 PM, presumably corresponding to a shift change of the NICU nursing staff. Ongoing analyses are examining whether 24-hour patterns of exposure are affected by bed type and location in the NICU. It is hoped that this line of study will lead to interventions designed to prevent audiological impairments associated with preterm birth and NICU environmental exposures. [Work supported by NIH Grant R21-DC017820.]