Stacking the evidence: Parents' use of acoustic packaging with preschoolers.

Segmenting continuous events into discrete actions is critical for understanding the world. As infants may lack top-down knowledge of event structure, caregivers provide audiovisual cues to guide the process, aligning action descriptions with event boundaries to increase their salience. This acoustic packaging may be specific to infant-directed speech, but little is known about when and why the use of this cue wanes. We explore whether acoustic packaging persists in parents' teaching of 2.5-5.5-year-old children about various toys. Parents produced a smaller percentage of action speech relative to studies with infants. However, action speech largely remained more aligned to action boundaries relative to non-action speech. Further, for the more challenging novel toys, parents modulated their use of acoustic packaging, providing it more for those children with lower vocabularies. Our findings suggest that acoustic packaging persists beyond interactions with infants, underscoring the utility of multimodal cues for learning, particularly for less knowledgeable learners in challenging learning environments.