Noise levels in a neonatal intensive care unit in the Cape metropole

Abstract

Introduction. Continuous noise exposure is potentially harmful to infants\' auditory systems and wellbeing. Although the effects of noise on infants in a neonatal intensive care unit (NICU) have been well researched overseas, limited studies have
been conducted in South Africa.
Aim. To conduct a detailed noise assessment in a state hospital NICU in the Cape metropole.
Study design and setting. Non-experimental descriptive design involving measurement, analysis and description of the noise levels and events in the NICU, Tygerberg Children\'s Hospital, Western Cape.
Method. Noise levels were measured over two 12-hour periods in both NICU rooms, during which observations were made to identify the sources and frequency of occurrence of NICU noises. Measurements of sound decay were made to determine whether the noise levels were a result of direct noise or reverberant noise from room reinforcements.
Results. Noise levels ranged from 62.3 to 66.7 dBA (LAeq), which exceeds American and British NICU standards (50 - 60 dBA). Staff conversations were the largest single contributor to the number of noise events. The largest single non-human contributor was monitor alarm noise. The NICU was found to be an extremely reverberant environment, suggesting that high noise levels were largely a result of reverberant room reinforcements.
Conclusion. Results highlight the need for noise reduction, which is vital to optimise newborn care, reduce acoustic trauma risks and enhance the infants\' wellbeing and physiological stability in the NICU. Moreover, it is especially important to limit NICU noise levels in developing countries as premature infants in the NICU are often at increased risk for developing noiseinduced sensorineural hearing loss as a result of NICU noise exposure and/or treatment with ototoxic medication and are often not routinely screened for hearing loss. Recommendations. Practical suggestions for noise reduction in the NICU are made.

South African Journal of Child Health Vol. 2 (2) 2008: pp. 50-54