Noise Exposure in the Neonatal Intensive Care Unit: A Prospective Study

Abstract

Objectives: 1) Describe the sound pressure levels experienced by premature infants in a neonatal intensive care unit (NICU) over an entire admission, compared to neonatal standards for sound exposure by the American Academy of Pediatrics (AAP) and Journal of Perinatology (JP), as well as adult standards by the National Institute for Occupational Safety and Health. 2) Determine whether this population may be at higher risk for noise-induced hearing loss. Methods: Prospective observational outcomes study from August 2012- present. Condition Studied: noise-induced hearing loss. Subjects: Admissions to the NICU, <37 weeks gestational age. Outcome Measurements: Sound pressure levels/cumulative sound exposure dosage. Independent Variables: bed type, location, number of patients per room, machine therapies. Preliminary Analyses: This dataset represents preliminary data from an ongoing study with a target enrollment of 150 over 12 months. Results: The average sound pressure level per admission ranged from 57.4 to 67.8 dBA. Neonates in enclosed beds experienced a trend toward higher decibel levels than those in open beds. Neonates on machines such as ventilators, continuous positive airway pressure (CPAP), or phototherapy were found to experience higher decibel levels. Conclusions: All infants received sound exposures that substantially exceeded AAP and JP guidelines of <45 dBA and <50 dBA for the NICU. Reducing NICU decibel levels should concentrate on bed design, individual alarm noise, and staff education regarding the sources and consequences of sound exposure. Newborn hearing screening protocols should consider additional testing to determine the risk of noise-induced hearing loss.