Thesis (MScMedSc (Interdisciplinary Health Sciences. Speech-Language and Hearing Therapy))--University of Stellenbosch, 2007. / Noise is a noxious stimulus with possible negative physiological effects on the infant, especially in the Neonatal Intensive Care Unit (NICU). The present study conducted a detailed noise assessment in a NICU of a state hospital in the Cape Metropole and documented 6 infants’ physiological responses to noise levels. Noise levels ranged from 62.3-66.7dBA (LAeq), which exceed all American and British standards (50dBA -60dBA) for a NICU. Continuous exposure to noise of these levels is potentially harmful to the infants’ auditory system and health stability. The general well-being of the staff working in the NICU may also be compromised. Analysis of the noise events revealed that staff conversations were the largest single contributor to the number of noise events, while the largest single non-human contributor was the alarm noise of the monitors. No significant correlations were found between the heart rates and noise levels and the respiratory rates and the noise levels for any of the participants in either room. The NICU was found to be an extremely reverberant environment, which suggested that the NICU noise levels were largely a result of reverberant noise reinforcements. NICU nursing staff’s most common suggestion for noise abatement strategies was reduction of staff conversation. Results of this study highlight the need for NICU noise abatement to optimise newborn patient care, reduce the risk of acoustic trauma and to improve the neonate’s quality of life, thus enhancing the infant’s physiologic stability, growth and health.