An analytical investigation into noise levels in public health sector neonatal intensive care units in the eThekwini District

Abstract

Background. Noise is a known environmental stressor in the neonatal intensive care unit (NICU), as it may result in adverse effects on preterm neonates because of the unique vulnerability and physiological immaturity of their central nervous systems. Objective. To investigate noise levels in public sector NICUs in the eThekwini District, KwaZulu-Natal Province, South Africa. Methods. An analytical observational study design with purposive sampling of public sector hospitals was used. Noise was continuously measured with a sound level meter in a central location for 48 hours on 2 consecutive days (Sunday and Monday) in the four NICUs. A sample of noise sources, as well as their frequency of occurrence, was identified through direct observation and a frequency spectrum analysis using one-third octave bands. Data were analysed using descriptive and inferential statistics. Results. This study included one tertiary hospital and three regional hospitals in the eThekwini District. Mean noise levels exceeded international recommendations of an A-weighted equivalent continuous sound level (LAeq) of 45 A-weighted decibel (dBA) and an A-weighted maximum sound level (LAmax) of 65 dBA in all four hospitals. The most frequently occurring sources of noise were staff conversations (30.9%, Hospital A), device alarms (21.0%, Hospital B) and closing metal pedal bins (20.0%, Hospital B). Mean LAeqs >45 BA were found in the mid and high frequencies (250 Hz - 6 300 Hz) in all hospitals, particularly during the afternoon. Conclusion. The findings emphasise the need for continuous noise monitoring, awareness and education among healthcare professionals in the NICU. Future research should expand on existing findings and focus on interventions for noise control in NICUs.