Noise and related events in a neonatal intensive care unit

The purposes of this study were to explore noise distribution, its timing, and sources of peak noise in the neonatal intensive care unit (NICU) of a University Hospital in Southern Taiwan. Two surveys on noise distribution and peak noise of the warmer bed were conducted. Noise at radiate heated beds located in the central sites of two areas, one near (Area A) and the other away from (Area B) the nursing station, were measured continuously for one week using an electronic sound-meter. Peak noise with a sound level of > 65 on the A-weighted decibel scale (dBA) and associated sources were recorded for 48 hours. Monitoring periods of peak noise consisted of a weekday and a day on the weekend randomly selected for Area A. Results showed that mean noise levels at the warmer bed in Areas A and B were 62 and 61.4 dBA on average. In over 70% of the total observation time for both areas the sound levels were > 59 dBA. The noise intensity was particularly high between 8 a.m. and 4 p.m. The noise level on the weekend was lower than that on weekdays. During the 48-hour observation period, 4994 peak noises were recorded. Eighty-six percent of these peak noises were within ranges of 65-74 dBA and 90% were human-related factors. The primary non-human related source was monitor alarms. Additionally, peak noises occurred primarily during the 8-11 a.m. and 2-4 p.m. hours on the weekdays and weekends. These results indicate that modifications of staff behavior, care procedures, and apparatus may reduce the noise levels in the NICU.