Preterm infants lack intrauterine sounds suitable for their development as they are born early. In addition, they are exposed to many unfamiliar sounds for weeks or months in the neonatal intensive care unit (NICU) where their follow-up and care are continued. It is known that the preterm infants hear the sounds from the extrauterine and respond to these sounds after the 26th gestational week. The types of the sounds and the level of the noise in the NICU is quite different from the uterus environment. The ambient noise composed of the ventilators, monitors, pagers and alarms of NICU take place of the low-frequency maternal voices in the amniotic environment. For this reason, the preterm infants lack the normal audial stimulants and they are disturbed by the sounds in the NICU environment. As a result, the development of the auditory and language skills and the socio-emotional development of the infants may get harmed. The recent evidences have suggested that the auditory learning and voice recognition experiences of the infants are based on their prenatal experiences. Therefore, it is quite important to make the preterm infants listen to their mothers' voice and the heart rate sound which they are lack of due to their preterm birth and therefore keeping them away from the sounds of the NICU environment.~In the light of this information, one of evidences is that the maternal voices have an effect on the physiological, neurobehavioral and autonomic functions of the preterm infants. Also, the fact that the maternal voice is a non-pharmacological and non-invasive application has importance for the preterm infant. Therefore, considering the optimal well-being of the infant, it is predicted that using the applications that simulate the extrauterine environment of the preterm infant to the intrauterine environment would decrease the stress behaviors of the infants and would provide the physiological values to be followed up in the positive direction, and as a result of these, it would contribute to supporting the recovery and shortening the discharge period.
Preterm infants lack intrauterine sounds suitable for their development as they are born early. In addition, they are exposed to many unfamiliar sounds for weeks or months in the neonatal intensive care unit (NICU) where their follow-up and care are continued. , one of evidences is that the maternal voices have an effect on the physiological, neurobehavioral and autonomic functions of the preterm infants. Also, the fact that the maternal voice is a non-pharmacological and non-invasive application has importance for the preterm infant. Therefore, considering the optimal well-being of the infant, it is predicted that using the applications that simulate the extrauterine environment of the preterm infant to the intrauterine environment would decrease the stress behaviors of the infants and would provide the physiological values to be followed up in the positive direction, and as a result of these, it would contribute to supporting the recovery and shortening the discharge period. The study was planned as a randomized controlled experimental design in order to determine the effect of the sound applied on the 26-37 week-old preterm infants on their heart rate, oxygen saturation and comfort level.