Auditory Exposure in the Neonatal Intensive Care Unit: Room Type and Other Predictors.

OBJECTIVE: To quantify early auditory exposures in the neonatal intensive care unit (NICU) and evaluate how these are related to medical and environmental factors. We hypothesized that there would be less auditory exposure in the NICU private room, compared with the open ward.

STUDY DESIGN: Preterm infants born at ≤ 28 weeks gestation (33 in the open ward, 25 in private rooms) had auditory exposure quantified at birth, 30 and 34 weeks postmenstrual age (PMA), and term equivalent age using the Language Environmental Acquisition device.

RESULTS: Meaningful language (P < .0001), the number of adult words (P < .0001), and electronic noise (P < .0001) increased across PMA. Silence increased (P = .0007) and noise decreased (P < .0001) across PMA. There was more silence in the private room (P = .02) than the open ward, with an average of 1.9 hours more silence in a 16-hour period. There was an interaction between PMA and room type for distant words (P = .01) and average decibels (P = .04), indicating that changes in auditory exposure across PMA were different for infants in private rooms compared with infants in the open ward. Medical interventions were related to more noise in the environment, although parent presence (P = .009) and engagement (P  = .002) were related to greater language exposure. Average sound levels in the NICU were 58.9 ± 3.6 decibels, with an average peak level of 86.9 ± 1.4 decibels.

CONCLUSIONS: Understanding the NICU auditory environment paves the way for interventions that reduce high levels of adverse sound and enhance positive forms of auditory exposure, such as language.