Active Overhearing: Development in Preschoolers' Skill at 'Listening in' to Naturalistic Overheard Speech

Overhearing can be seen as active learning, and overheard speech provides an increasingly viable source of linguistic input across development. This study extends previous results showing learning from overhearing simplified, pedagogic speech to a more ecologically valid context. Children learn multiple words and facts corresponding to novel toys either through an overheard phone call or through direct instruction. Remarkably, 4.5–6-year-olds learned four new words equally well in both conditions. Their performance on a set of six facts was even better, especially when taught directly. Analysis of the videos revealed that older children with high test accuracy both looked toward the experimenter often, and tracked objects as she discussed them. 3–4.5-year-olds only learned facts from overhearing, and exhibited greater varability in attention. These results suggest learning from overhearing is driven by attention to the indirect input, and may be a skill that undergoes substantial development during the preschool years.