AbstractBackgroundHigh‐risk newborns, such as premature or severely ill infants, often experience painful treatments and separation from their parents. While previous studies have focused on the positive impacts of a mother's voice on newborns' physiology and pain response, research on the father's voice and vocal acoustics in high‐risk newborns is limited.AimTo examine whether parents' voices reduce heel puncture pain in high‐risk newborns and the relationship between parents' vocal acoustics, physiological parameters and pain response.Study DesignA randomized controlled clinical trial was conducted with 105 high‐risk newborn–parent dyads. Participants were randomly assigned to three groups: recorded mother's voice, recorded father's voice or control group without any recorded voice. Outcome measures included heart rate, respiratory rate, oxygen saturation and pain response assessed using the Neonatal Infant Pain Scale. Data analysis utilized generalized estimation equations, and parents' vocal acoustics were analysed using Praat voice credit software.ResultsThe mother's voice group exhibited significantly lower heart rates at 1, 5 and 10 min after the procedure, along with lower respiratory rates and pain levels at 5 and 10 min after the procedure compared with the control group. Similarly, the father's voice group demonstrated significantly lower heart rates at 1 and 5 min after the procedure, decreased respiratory rates at 5 and 10 min after the procedure and reduced pain levels at 1 and 5 to 10 min after the procedure compared with the control group. Higher minimum and mean pitches in parents' voices correlated with slower heart rates, while slower parental speech was associated with reduced newborn pain.ConclusionBoth maternal and paternal vocal interventions alleviated pain during heel puncture procedures among high‐risk newborns.Relevance to Clinical PracticeThe noninvasive intervention serves as a reference for parental participation in care. Nurses can help parents to intervene with the acoustic characteristics that alleviate pain among high‐risk newborns.