Efficacy of noise reduction bundle in reducing sound levels in a Level II neonatal care unit in China

BACKGROUND: Noise is a hazard for newborns. Preterm infants are more vulnerable to negative effects of noise because their auditory system is at a critical period of neurodevelopment. We conducted this study to determine whether noise exposure in our Level II unit met the American Academy of Pediatrics (AAP)-issued recommendation of less than 45 dB. We also aimed to assess the efficacy of a bundle of noise reduction methods and the role of noise supervisors in assuring the compliance of modification. METHODS: Hourly mean equivalent continuous noise level (Leq) was collected in two phases: (I) Phase 1: baseline data for 4 weeks, (II) Phase 2: study period for 13 weeks, 1 week (Stage 1) under close monitoring by the noise supervisors and 12 weeks (Stages 2, 3 and 4, lasting 4 weeks each) without supervisors. RESULTS: The baseline noise level consistently exceeded recommendations with an hourly mean incubator noise of 53.6 dB (±5.2). Our bundle resulted in a significant reduction in incubator noise levels by 9.1 dB (±0.75). The sound levels remained