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…

By 12 months of age, infants exhibit behavioral sensitivity to sound symbolism (e.g. sound-shape correspondences) when they hear universally sound symbolic pseudowords (e.g. "bouba," "kiki"). Here, we investigated whether infant's sensitivity to sound-shape correspondences is affected when they hear language-specific sound…

The present study investigates the role of three structural factors ("word order," "case-marking," and "verbal morphology") in the comprehension of the Korean suffixal passive by Korean-speaking children. To measure the relative impact of each factor on the comprehension of the passive, we devise a novel method where…

Background noise challenges auditory recognition of speech and may reveal the underlying deficits in auditory word recognition skills. Previous studies have reported an association between children's auditory skills and various linguistic skills, including phonology, although in some languages only. However, language-specific features influence…

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…

Children's ability to learn words with multiple meanings may be hindered by their adherence to a one-to-one form-to-meaning mapping bias. Previous research on children's learning of a novel meaning for a familiar word (sometimes called a "pseudohomophone") has yielded mixed results, suggesting a range of factors that may impact when…

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…

A child word-learning experiment is reported that examines 2- and 3-year-olds' ability to learn the meanings of novel words across multiple, referentially ambiguous, word occurrences. Children were told they were going on an animal safari in which they would learn the names of unfamiliar animals. Critical trial sequences began with hearing a novel…

One of the first challenges facing the young language learner is the task of segmenting words from a natural language speech stream, without prior knowledge of how these words sound. Studies with younger children find that children find it easier to segment words from fluent speech when the words are presented in infant-directed speech, i.e., the…

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…

Research has shown that young infants use contrasting acoustic information to distinguish consonants. This has been used to argue that by 12 months, infants have homed in on their native language sound categories. However, this ability seems to be positionally constrained, with contrasts at the beginning of words (onsets) discriminated earlier.…

We examined how toddlers process lexical ambiguity where different underlying forms are neutralized at the surface level. In a preferential-looking procedure, French-learning 30-month-olds were familiarized with either liaison-ambiguous phrases (i.e., sentences containing a determiner and a non-word, e.g., "ces /z/onches," "these…

Word order is a core mechanism for conveying syntactic structure, yet interrogatives usually disrupt canonical word orders. For example, in English, polar interrogatives typically invert the subject and auxiliary verb and insert an utterance-initial "do" if no auxiliary is present. These word order patterns result from differences in the…

A major problem in second language acquisition (SLA) is the segmentation of fluent speech in the target language, i.e., detecting the boundaries of phonological constituents like words and phrases in the speech stream. To this end, among a variety of cues, people extensively use prosody and statistical regularities. We examined the role of pitch,…

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…