In six experiments with English-learning infants, we examined the effects of variability in voice and foreign accent on word recognition. We found that 9-month-old infants successfully recognized words when two native English talkers with dissimilar voices produced test and familiarization items (Experiment 1). When the domain of variability was shifted to include variability in voice as well as in accent, 13-, but not 9-month-olds, recognized a word produced across talkers when only one had a Spanish accent (Experiments 2 and 3). Nine-month-olds accommodated some variability in accent by recognizing words when the same Spanish-accented talker produced familiarization and test items (Experiment 4). However, 13-, but not 9-month-olds, could do so when test and familiarization items were produced by two distinct Spanish-accented talkers (Experiments 5 and 6). These findings suggest that, although monolingual 9-month-olds have abstract phonological representations, these representations may not be flexible enough to accommodate the modifications found in foreign-accented speech.

In most of the world, people have regular exposure to multiple accents. Therefore, learning to quickly process accented speech is a prerequisite to successful communication. In this paper, we examine work on the perception of accented speech across the lifespan, from early infancy to late adulthood. Unfamiliar accents initially impair linguistic processing by infants, children, younger adults, and older adults, but listeners of all ages come to adapt to accented speech. Emergent research also goes beyond these perceptual abilities, by assessing links with production and the relative contributions of linguistic knowledge and general cognitive skills. We conclude by underlining points of convergence across ages, and the gaps left to face in future work.

Both subjective impressions and previous research with monolingual listeners suggest that a foreign accent interferes with word recognition in infants, young children, and adults. However, because being exposed to multiple accents is likely to be an everyday occurrence in many societies, it is unexpected that such non-standard pronunciations would significantly impede language processing once the listener has experience with the relevant accent. Indeed, we report that 24-month-olds successfully accommodate an unfamiliar accent in rapid word learning after less than 2 minutes of accent exposure. These results underline the robustness of our speech perception mechanisms, which allow listeners to adapt even in the absence of extensive lexical knowledge and clear known-word referents.

Toward the end of their first year of life, infants' overly specified word representations are thought to give way to more abstract ones, which helps them to better cope with variation not relevant to word identity (e.g., voice and affect). This developmental change may help infants process the ambient language more efficiently, thus enabling rapid gains in vocabulary growth. One particular kind of variability that infants must accommodate is that of dialectal accent, because most children will encounter speakers from different regions and backgrounds. In this study, we explored developmental changes in infants'