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…

Previous research on infant-directed speech (IDS) and its role in infants' language development has largely focused on mothers, with fathers being investigated scarcely. Here we examine the acoustics of IDS as compared to adult-directed speech (ADS) in Norwegian mothers and fathers to 8-month-old infants, and whether these relate to direct…

Bilingual infants must navigate the similarities and differences between their languages to achieve native proficiency in childhood. Bilinguals learning to find individual words in fluent speech face the possibility of conflicting cues to word boundaries across their languages. Despite this challenge, bilingual infants typically begin to segment…

Before infants can learn words, they must identify those words in continuous speech. Yet, the speech signal lacks obvious boundary markers, which poses a potential problem for language acquisition (Swingley, "Philos Trans R Soc Lond. Series B, Biol Sci" 364(1536), 3617-3632, 2009). By the middle of the first year, infants seem to have…

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…

In a series of studies, we examined how mothers naturally stress words across multiple mentions in speech to their infants and how this marking influences infants' recognition of words in fluent speech. We first collected samples of mothers' infant-directed speech using a technique that induced multiple repetitions of target words. Acoustic…

Little research has been conducted on the development of suprasegmental characteristics of vocalizations in typically developing infants (TDI) and the role of audition in the development of these characteristics. The purpose of the present study was to examine the longitudinal development of fundamental frequency (F[subscript 0]) in eight TDI and…

Infants heard sentences in which prosodic structure was either consistent or inconsistent with the syntactic structure. Results suggest that the prosodic information in an individual sentence is not always sufficient to assign a syntactic structure and that learners must engage in active inferential processes to arrive at the correct syntactic…

Infants' phonological acquisition during the first 18 months of life has been studied within experimental psychology for some 30 years. Current research themes include statistical learning mechanisms, early lexical development, and models of phonetic category perception. So far, linguistic theories have hardly been taken into account. These…

A series of experiments investigated infants' perception of inherent structural organization in the prosody of utterances. The experiments used a listening preference procedure to test: perceptions of appropriate pauses in child-directed and adult-directed speech; perceptions of appropriate pauses in speech filtered for most segmental features but…