During the care, from the beginning to the end, mother's voice was played to the newborns. It took about 20 minutes. The mini Bluetooth speaker and the decibel meter were disinfected with the rapid surface disinfectant used in the clinic. The speaker was placed 30 cm away from the infant's ear and the sound level in the incubator was adjusted to be 50-60 dB by using a decibel meter. Mother's voice was played from the beginning of the provision of care and continued for 15 minutes after the end of the provision of care. During the provision of care, COMFORTneo scores, pain scores, and vital signs were measured and recorded on the vital signs follow-up form.

Standard nursing care lasting 20 minutes was performed in the routine sound environment of the neonatal intensive care unit. COMFORTneo scores, pain scores, and vital signs were measured and recorded on the vital signs follow-up form.

During the care, from the beginning to the end, mother's voice was played to the newborns. It took about 20 minutes. The mini Bluetooth speaker and the decibel meter were disinfected with the rapid surface disinfectant used in the clinic. The speaker was placed 30 cm away from the infant's ear and the sound level in the incubator was adjusted to be 50-60 dB by using a decibel meter (Official Gazette, 2018). Mother's voice was played from the beginning of the provision of care and continued for 15 minutes after the end of the provision of care. During the provision of care, COMFORTneo scores, pain scores, and vital signs were measured and recorded on the vital signs follow-up form.

The scale is for 0-100-day-old infants and term or preterm newborns experiencing acute or chronic pain and treated with or without mechanical ventilation.

COMFORTneo consists of 7 items on alertness, calmness/agitation, respiratory response, crying, body movement, facial tension, and muscle tone. Of these items, "respiratory response" is evaluated in newborns on mechanical ventilation and "crying" is evaluated in spontaneously breathing newborns.