Effects of recorded maternal voice on heart rate and anthropometric parameters in premature infants: A randomized controlled trial

INTERVENTION: A specialized NICU nurse will trained for carrying out the study protocol and help mothers recording their voice. The mothers' voice will be recorded in agreement with the American Academy of Pediatrics guidelines. Mothers will be instructed by the research and nurse to record the words in a quiet environment in the same manner they had spoken to the fetus during pregnancy. They will be informed that there is no restriction of the recording content (e.g., story, nursery rhymes) and length. Then, they will be asked to talk into a recorder. so every neonate heard its maternal voice with her special words, feelings and speech. The maternal voice will broadcast two times a day, with each time lasting 30 minutes (between 7 and 8 am, and 16 and 17 pm) for premature infants while they were alert and awake and had received nursing care before intervention. The recorded voice will be played on repeat from 48 hours of birth until infants are discharged from the hospital. To ensure the authenticity of the function of the devices during the intervention, the infant’s nurse will present at the bedside. In order to omit additional sounds around the participants, the intervention will be performed in one of the isolated rooms of the NICU where the noise and traffic are the least. To ensure the infants' auditory safety, the intensity of maternal voice will be monitored individually for each infant to be between 35 and 85db. The recorded voice will be broadcast placed approximately 20‐30cm from the infants' heads. CONDITION: heart rate;anthropometric parameters ; ; heart rate ; anthropometric parameters Reproductive Health and Childbirth ‐ Other reproductive health and childbirth disorders PRIMARY OUTCOME: heart rate using heart rate monitoring devices[The infants' heart rate will be recorded seven times per day during the intervention, regular heart rate at 7.30 am in the morning, 1min before the morning intervention, middle of the morning intervention, 10mins after the morning intervention, 1 min before the afternoon intervention, middle of the afternoon intervention, and 10 mins after the afternoon intervention] weight and recumbent length using a digital baby scale with a protable length board (seca‐376 digital baby scale); head circumference using a soft tape; [baseline, daily recorded during the intervention, and at the end of the intervention] SECONDARY OUTCOME: Nil[Nil] INCLUSION CRITERIA: The participants will be premature infants at the NICU. Details of the inclusion criteria are as follows: 1. born after 28th or before 34th week of gestation 2. medically stable during the first 24 hour after birth (e.g., heart rate, blood pressure, age‐appropriate rate, body temperature) 3. had no congenital malformation that could have caused asphyxia