Chen 2021.

Methods	Study design: between‐group Total study duration: 2 to 3 months
Participants	Total number: 116 Setting: hospital Diagnostic criteria: full‐term at birth Gestational age: gestational age of at least 32 weeks Control: 38.5 ± 1.7 Experimental: 38.5 ± 1.6 Sex: Males: 26 Females: 32 Country: China
Interventions	Total number of intervention groups: 1 Control group description: control group received routine care which consisted of swaddling using a blanket Total number of participants randomised to each of the groups: 58 Specific intervention: on top of routine care, maternal voice was played to the neonate by a voice recorder on one side of the head at a distance of 20 cm from the neonate's ear. The sound was set between 50 and 60 decibels by using a decibel meter. Maternal voice was played for 2 minutes before the procedure and until the neonate's heart rate and oxygen saturation returned to baseline.
Outcomes	NIAPAS A 2, 3, or 4‐point scale (0, 1; or 0, 1, 2; or 0, 1, 2, 3) for a possible total score of 18 High score = more pain Continuous Adverse events: trial did not report on adverse events
Notes	Key conclusions of study authors:  Behavioural and physiological indicator scores in the maternal voice group were significantly lower compared with those in the routine care group Study funding source: funds from School of Nursing, Peking Union Medical College Author COI statement: none