Vocal responsiveness of preterm infants to maternal infant-directed speaking and singing during skin-to-skin contact (Kangaroo Care) in the NICU

•Compared to baseline preterm babies vocalize less during maternal singing or speaking.•Preterm babies’ latency time is shorter in maternal singing than in maternal speaking.•Maternal singing prompts preterm babies’ overlapping vocalizations.•Maternal speaking increases preterm babies’ vocalizations during pauses.•Maternal singing favors co-modulation in preterm dyads.