The frequency spectrum of the acoustic environment in a neonatal intensive care unit

Abstract

Objectives: The acoustic frequencies present in an incubator are within the hearing range of a newborn; this requires adapting the environment so that the noise inside the incubator is more compatible with that range and facilitates proper hearing development. The objective of this study is to make a comparison, in thirds of an octave (frequency analysis), of the noise present in the NICU room and the interior space of the incubator, analyzing the ambient acoustic quality perceived by the newborn. Methods: The experiment carried out in this work consisted of two series of measurements of noise levels in the NICU of the “Puerta del Mar” University Hospital (Cádiz, Spain) and two selected incubators in the room. A third-octave frequency band analysis was performed within the audible field (20 Hz/20 kHz). Data were recorded at 1 s intervals for more than 24 h (3600 registers de 1 s.) Results and conclusions: One may wonder if noise levels inside incubators affect newborns. Based on existing references, the answer is probably “yes”, since the frequencies present inside an incubator are within the audible range of a newborn. According to the consulted bibliography, the audible range of neonates is between 400 Hz and 4 kHz. In this work, the acoustic measurements carried out in the NICU made it possible to evaluate the noise levels in the room and inside the incubators. According to the results, the indicator used LAeq, 1 h, should be complemented with a study in 1/3 octave bands (frequency analysis) to determine the acoustic quality and hearing protection of neonates