There is a long-standing debate in the literature about the benefits that acoustic components of Infant Directed Speech (IDS) might have for infants' language acquisition. One of the highly contested features is vowel space expansion, which refers to the enlargement of the acoustic space between the corner vowels /i, u, a/ in IDS compared to Adult…

Over time, people who spend a lot of time together (e.g., roommates) begin sounding alike. Even over the course of short conversations, interlocutors often become more acoustically similar to one another. This phenomenon -- known as phonetic alignment -- has been well studied in adult interactions, but much less is known about alignment patterns…

An important issue regarding developmental changes in cue weighting is whether children weight the dynamic cue of vowel formant transitions relatively more than do adults, whereas adults depend more on the static cue of the fricative noise level. We investigated this issue in Brazilian Portuguese. Additionally, we inserted the segment to be…

Previous research has shown that an increased second language (L2) vocabulary size leads to better attunement to the cues required to distinguish L2 contrastive phones. This has been the central tenet of the vocabulary-tuning model (vocab) on the basis of evidence by Japanese learners of English in Australia. We aim to test the validity of the…

Many approaches to early word learning posit that children assume a one-to-one mapping of form and meaning. However, children's early vocabularies contain homophones, words that violate that assumption. Children might learn such words by exploiting prosodic differences between homophone meanings that are associated with lemma frequency (Gahl,…

We tested 12- and 18-month-old English-learning infants on a preferential-looking task which contrasted grammatically correct sentences using the determiner "the" vs. three ungrammatical conditions in which "the" was substituted by another English function word, a nonsense word, or omitted. Our design involved strict controls…

In spontaneous conversations between adults, words are often pronounced with fewer segments or syllables than their citation forms. The question arises whether infant-directed speech also contains phonetic reduction. If so, infants would be presented with speech input that enables them to acquire reduced variants from an early age. This study…