The Effect of White Noise and Buzzy Use on Pain During Infant Vaccination: A Randomized Controlled Trial

Pain during routine vaccination is a common clinical challenge in infancy. Although short in duration, procedural pain can cause significant distress for infants and caregivers, and repeated painful experiences during early life have been associated with negative physiological, behavioral, and neurodevelopmental outcomes. Current guidelines from pediatric and neonatal organizations emphasize the importance of minimizing pain through safe, effective, and feasible strategies. Non-pharmacological methods such as white noise and vibration-cold devices (e.g., Buzzy) are increasingly recommended because they are simple, inexpensive, and easily integrated into routine clinical workflows. However, there is limited evidence comparing the effectiveness of these two methods specifically during infant vaccination.

This study is designed as a single-center, randomized controlled, experimental trial aimed at evaluating and comparing the effects of white noise and the Buzzy device on pain experienced by infants during vaccination. The study will be conducted at the Büyükçekmece Central Family Health Center in Istanbul, Türkiye, between October 2025 and October 2026. The target population includes healthy infants aged 0 to 6 months who are scheduled to receive the routine hexavalent vaccine (diphtheria, acellular pertussis, tetanus, inactivated polio, Haemophilus influenzae type B, and hepatitis B).

A total of 108 infants will be included based on a priori power analysis performed using G*Power software, assuming an alpha level of 0.05, a power of 95%, and an anticipated large effect size. To account for potential dropout or exclusions, 36 infants will be assigned to each of the three study groups: (1) White Noise Group, (2) Buzzy Device Group, and (3) Control Group. Randomization will be conducted by an independent statistician using stratified randomization based on infant age (2, 4, or 6 months) and sex to ensure balanced distribution across groups. The study will use a single-blind design in which the observer assessing pain scores is blinded to group assignment.

In the White Noise Group, infants will listen to white noise beginning approximately 1 to 2 minutes before the vaccination and continuing throughout the procedure. The device will be placed safely within hearing distance of the infant. In the Buzzy Group, the Buzzy device-providing combined vibration and cold stimulation-will be applied approximately 3 cm above the injection site starting 60 seconds before the injection and will remain active until the end of the vaccination. In the Control Group, infants will receive the standard vaccination procedure without additional intervention. All vaccinations will be performed by the same trained nurse to ensure procedural consistency. A parent will remain present for the infant's comfort and to assist in observing behavioral cues.

Pain will be evaluated using the validated FLACC Pain Assessment Scale (Face, Legs, Activity, Cry, Consolability), a widely used behavioral tool suitable for infants and young children. During the vaccination, pain scores will be independently assessed by both a blinded observer (trained research nurse) and the parent. The total FLACC score ranges from 0 (no pain) to 10 (severe pain). Higher scores indicate greater pain. Sociodemographic data for infants and parents will also be collected using a structured introductory information form developed from relevant literature.