“…When engaging with infants, caregivers naturally use the distinctive speaking style of infant-directed speech (IDS), which is characterized by acoustic features of heightened pitch, exaggerated pitch contours, slower tempo, increased rhythmicity, and increased temporal and pitch variability compared to adult-directed speech (Falk & Kello, 2017;Ferguson, 1964;Fernald, 1991;Katz et al, 1996;Papoušek, 1992;Stern et al, 1982;Trehub et al, 1993;Wang et al, 2018). These features of IDS capture and modulate infant attention and arousal to facilitate social interaction and learning (e.g., such as by using duration, intensity, and pitch accents to accentuate important linguistic information) (Räsänen et al, 2018;Senju & Csibra, 2008;Singh et al, 2009;Thiessen et al, 2005;Woolard et al, 2021).…”