Language acquisition during infancy and early childhood is a crucial predictor of children's future academic success (Hart & Risley, 1995; Huttenlocher et al., 2002) and social development (Robertson & Ellis Weismer, 1999). Early attempts to characterize children's language development often relied on diary methods (e.g., Tomasello, 1992) or naturalistic observations (e.g., Hart & Risley, 1995) to record and transcribe the language to which children are exposed and produce. While these methods provided valuable insight into variability in children's early language skills, such approaches were often limited by practical constraints (e.g., time requirements for manually transcribing and annotating naturalistic speech) and ecological concerns. To address these limitations, more recent methods have leveraged advancements in audio recording technologies. This article focuses on the most widely used of these methods: the Language ENvironment Analysis (LENA™) system (Gilkerson & Richards, 2008a, pp. 15–17).
