Newborns in this group receive researcher-delivered vocal shooting during nursing care procedures in the NICU.

Newborns in this group will not undergo any intervention by the researcher; routine care procedures will be applied.

Prior to the afternoon routine care in the Neonatal Intensive Care Unit, baseline assessments will be completed by the selected clinical nurse using the Neonatal Stress Scale and Neonatal Follow-up Form. During the approximately 10-minute routine care procedure (eye care, oral care, diaper change, probe repositioning, and weight measurement), the investigator will administer a verbal reassurance intervention. The intervention involves speaking to the newborn calmly, reassuringly, and lovingly from a distance of approximately 20 cm, maintaining eye contact and minimizing environmental stimuli. The volume will be kept between 45-60 dB. Outcome measurements will be repeated by the same nurse 5 minutes after the start of care and 5 minutes after the completion of care.

The Neonatal Stress Assessment Scale (NISS) was developed by Ceylan and Bolışık (2017) to assess stress levels in premature infants. The scale consists of 24 items on a 3-point Likert scale, comprising 8 subgroups including facial expression, body color, breathing, activity level, soothing ability, muscle tone, extremities, and posture. Each subgroup is scored from 0 to 2 points. The minimum score is 0, and the maximum is 16. A high score indicates increased stress. The scale is evaluated through observation. It is sufficient for the infant to exhibit only one behavior from each cell in their free-standing space. A high value is valid if the infant exhibits behaviors from two different cell types (for example, if the infant shows signs corresponding to both 1 and 2 points). A stable and regular state indicates a high value of 0.

The newborn care duration, oxygen saturation, and pulse of newborns in the intervention and control groups will be recorded using the newborn follow-up form.