In this article, I present a selective review of research on speech perception development and its relation to reference, word learning, and other aspects of language acquisition, focusing on the empirical and theoretical contributions that have come from my laboratory over the years. Discussed are the biases infants have at birth for processing speech, the mechanisms by which universal speech perception becomes attuned to the properties of the native language, and the extent to which changing speech perception sensitivities contribute to language learning. These issues are reviewed from the perspective of both monolingual and bilingual learning infants. Two foci will distinguish this from my previous reviews: first and foremost is the extent to which contrastive meaning and referential intent are not just shaped by, but also shape, changing speech perception sensitivities, and second is the extent to which infant speech perception is multisensory and its implications for both theory and methodology.

This study examines the acquisition of /r/ in German and Spanish monolingual and bilingual children. German and Spanish are characterized by different /r/s. German has a uvular approximant whereas Spanish has an alveolar tap and trill. Words containing /r/ were extracted from longitudinal recordings of the children, aged 1;9 to 3;6. Results indicate that monolingual German children acquired uvular /r/ earlier than monolingual Spanish children acquired the tap and trill. The bilingual children acquired uvular /r/ similarly to the monolingual children or, in the case of /r/ clusters, they were mildly delayed. They were advanced in the acquisition of alveolar tap and they produced more /r/-like errors for the trill. Transfer patterns were observed in one child but they could not be explained by markedness or language dominance. Findings are consistent with cross-linguistic interaction in the acquisition of /r/, in which the phonological systems of the bilinguals approximate each other.