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…

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…

Research on the acoustic characteristics of Infant Directed Speech (IDS) in North American English indicates that it is generally higher-pitched than Adult Directed Speech (ADS) and has unique prosodic characteristics, which is commonly found across many spoken languages. However, very little research has addressed another important aspect of…

Applying an eye-tracking technique, we tested early verb understanding in 48 infants aged 9 and 10 months. Infants saw two objects presented side by side and heard a verb that referred to a common action with one of these objects (e.g., eating relating to a banana). The verbs were spoken by the parent in an interrogative manner in order to elicit…

Infant-directed speech (IDS) is characterized by a range of register-typical characteristics. Many of those can be objectively measured, such as acoustic-prosodic and structural-linguistic modifications. Perceived vocal affect, however, is a socio-emotional IDS characteristic and is subjectively assessed. Vocal affect goes beyond acoustic-prosodic…

Although both fathers and mothers speak differently in infant-directed speech (IDS) compared to adult-directed speech (ADS), the acoustic characteristics of present-day paternal IDS are still insufficiently understood. To extend this understanding, 11 fathers and 17 mothers in The Netherlands were recorded interacting with their infant…

Using a habituation paradigm with a three-switch design, the present study investigated whether 20-month-old French-learning infants use noun and verb morphosyntactic cues to learn novel words in dynamic events differentially when both the agent and the action interpretations are possible. Of particular interest was whether infants' initial…

Non-tone language infants' native language recognition is based first on supra-segmental then segmental cues, but this trajectory is unknown for tone-language infants. This study investigated non-tone (English) and tone (Thai) language 6- to 10-month-old infants' preference for English vs. Thai one-syllable words (containing segmental and tone…

Successful word recognition requires that listeners attend to differences that are phonemic in the language while also remaining flexible to the variation introduced by different voices and accents. Previous work has demonstrated that American-English-learning 19-month-olds are able to balance these demands: although one-off one-feature…

Crosslinguistic research into language development reveals that typological features determine children's developmental patterns to a large extent. The present study examines the early morphological development in the verb inflectional paradigm in Bangla. Data from the first 6 months since the emergence of two-word combinations were collected from…

Hyper-articulation of vowel and consonant contrasts is often reported in infant-directed speech (IDS), but is not universal cross-linguistically, and may be a side-effect of speaking rate. This study investigated the voicing characteristics of the four-way oral stop voicing contrast in Nepali IDS. Both lead and lag time of word-onset/g,…

Researchers disagree as to the importance for infant language learning of isolated words, which occur relatively rarely in input speech. Brent and Siskind (2001) showed that the first words infants "produce" are words their mothers used most frequently in isolation. Here we investigate the long-term effects of presentation mode on…

Previous research indicates that infant-directed speech (IDS) is usually slower than adult-directed speech (ADS) and mothers prefer placing a focused word in isolation or utterance-final position in (English) IDS, which may benefit word learning. This study investigated the speaking rate and word position of IDS in two typologically-distinct…

Assessing a child's language in the early years is critical to plan for an early intervention and maximize their learning potential. In a unique pan-Arabic approach to language development, we developed a new Arabic assessment tool, usable by parents and Early Years professionals to screen vocabulary in children between 8 months and 30 months…

Our aim was to investigate perceptual attunement (PA) in vowel perception of Dutch-learning infants (6-8-10-month-olds) using the hybrid visual fixation paradigm (Houston et al., 2007). Infants were habituated to one phoneme and subsequently tested on items in which a token of the habituated phoneme alternated with either another token of the same…