With Referential Cues, Infants Successfully Use Phonetic Detail in Word Learning

The relation between speech perception and word learning in infancy has become a focus for research in early language acquisition (e.g., Fikkert, 2005; Jusczyk & Aslin, 1995; Swingley & Aslin, 2002; Werker, Fennell, Corcoran & Stager, 2002). Considerable attention has been paid to a surprising discrepancy. Although infants’ performance in speech discrimination tasks reveals their sensitivity to phonetic detail in their native language (e.g., Werker & Tees, 1984), they apparently have difficulty recruiting detailed phonetic information in the task of word learning. Indeed, there are several reports of infants and toddlers having difficulty distinguishing between similar-sounding words in their initial lexicon (e.g., Barton, 1980; Brown & Matthews, 1997; Stager & Werker, 1997). The aim of this paper is to demonstrate that this discrepancy is not robust. We provide evidence that infants do indeed recruit their refined phonetic perception skills in their early word learning. When the word learning situation is facilitated by clarifying the referential status of the novel word, infants successfully attend to relevant sound distinctions. These findings support the cognitive load hypothesis (Werker & Fennell, 2004), a theoretical position that argues for continuity in the sound representations used in infant speech perception and early word learning.