The mothers were asked to sing lullabies, and their voices were recorded in a quiet environment. Which lullaby they would sing was left to the mothers' discretion, and the audio recording process took an average of 2-3 minutes. The voice recordings taken were applied for a total of 15 minutes before, during and after the nasal CPAP application.The NIPS and PICS scores were evaluated and recorded before, during and after the application.

Therapeutic touch was started 5 minutes before nasal prongs were placed, and was applied for 5 minutes during the application, and continued for another 5 minutes after the nasal prongs were placed. The method was applied for a total of 15 minutes as 5 minutes of hand resting, 5 minutes of gentle caressing and 5 more minutes of hand resting.The NIPS and PICS scores were evaluated and recorded before, during and after the application.

Both applications were applied together for 15 minutes.The NIPS and PICS scores were evaluated and recorded before, during and after the application.

The premature babies in the control group did not receive any intervention other than the hospital procedure.The NIPS and PICS scores were evaluated and recorded before, during and after the application.

The audio recording was made to listen to the baby for 15 minutes during the nasal CPAP application. The NIPS and PICS scores were evaluated and recorded before, during and after the application.

Neonatal Infant Pain Scale (NIPS) was developed by Lawrence et. al. in 1993 in order to assess intervention-related pain in term and preterm babies (Lawrence et al., 1993). The Turkish validity and reliability of the study was conducted in 1999 by Akdovan (Akdovan, 1999). NIPS has six sections on facial expression, crying, respiration state, movements of extremity, and being awake. All behavioral responses except for crying were given two separate scores (0-1 score). Three separate scores were assigned (0-1-2) to crying. The total scores were between 0-7. A high score showed that pain was more intense (Yilmaz & Arikan, 2011). The Cronbach's a coefficients before, during, and after the intervention were found to be 0.95, 0.87, and 0.88, respectively, by Lawrence et al. (Lawrence et al., 1993).The Neonatal Infant Pain Scale (NIPS) score was evaluated and recorded before, during and 15 minutes after the application.

Premature Infant Comfort Scale (PICS) which was developed by Ambuel et. al. (Ambuel et al., 1992) in order to the measure pain and stress levels of 0-18-month-old children, was later adapted to 28-37-week-old premature infants by Monique et. al. in 2007 (Caljouw et al., 2007) The Premature Infant Comfort Scale assesses 7 parameters such as Awareness, Tranquility/Agitation, Respiration State (only supported by mechanical ventilation) or Crying (it was not assessed because it was scored only in children with spontaneous respiration), Physical Movement, Muscular Tonus, Facial Expressions and Average Cardiac Beat. The scale is 5-point Likert type. As the scale score increases, the comfort level decreases. The scores are between 35 and 7. Comfort decreases as it approaches 35 points, and increases as it approaches 7 points. (Küçük Alemdar & Güdücü Tüfekci, 2015).Premature Infant Comfort Scale (PICS) score was evaluated and recorded before, during and 15 minutes after the application.