The aim of the project is to study the environmental noise effects on the neonates and a proposal to attenuate them. This Final Project pretends to identify where the noise comes from in the Neonatal Unit and its value in decibels and to compare the decibels measured with those established by the American Academy of Pediatrics and the Environmental Health Committee. Both advise not to exceed 45 decibels during the day and 35 decibels at night. Also, I want to propose a maximum value of decibels for the Neonatal Intensive Care Unit according to the results obtained. Too, this work will analyse if the premature’s physiological changes are related with the noise they are exposed to during the long period of time that they must habituate. Finally, some attenuating measures with the purpose of reduce the noise levels and create an appropriate welfare for the preterm infants are proposed.