Before they even talk, infants become sensitive to the speech sounds of their native language and recognize the auditory form of an increasing number of words. Traditionally, these early perceptual changes are attributed to an emerging knowledge of linguistic categories such as phonemes or words. However, there is growing skepticism surrounding…

Seminal work by Werker and colleagues (Stager & Werker [1997] "Nature," 388, 381-382) has found that 14-month-old infants do not show evidence for learning minimal pairs in the habituation-switch paradigm. However, when multiple speakers produce the minimal pair in acoustically variable ways, infants' performance improves in…

The current study examined the phonolexical processing of Mandarin segments and tones by English speakers at different Mandarin proficiency levels. Eleven English speakers naive to Mandarin, 15 intermediate and 9 advanced second language (L2) learners participated in a word-learning experiment. After learning the sound and meaning of 16 Mandarin…

Children are adept at learning their language's speech-sound categories, but just how these categories function in their developing lexicon has not been mapped out in detail. Here, we addressed whether, in a language-guided looking procedure, 2-year-olds would respond to a mispronunciation of the voicing of the initial consonant of a newly learned…

The ability to map similar sounding words to different meanings alone is far from enough for successful speech processing. To overcome variability in the speech signal, young learners must also recognize words across surface variations. Previous studies have shown that infants at 14 months are able to use variations in word-internal cues (i.e.,…

The question of whether second languages (L2s) are best learned implicitly or explicitly has been a topic of much empirical discourse, with the majority of studies pointing to the benefits of explicit instruction when learning L2 grammar rules. However, given the focus on grammar, it is unclear how generalizable these findings are to other…

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…

Purpose: When learning novel word forms, preschoolers with developmental language disorder (DLD; also known as "specific language impairment") produce speech targets inaccurately and with a high degree of intraword variability. The aim of the current study is to specify whether and how layering lexical-semantic information onto novel…

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 Findings: The present study compared effects of explicit instruction on and practice with the phonological form of words (form-focused instruction) versus explicit instruction on and practice with the meaning of words (meaning-focused instruction). Instruction was given via interactive storybook reading in the kindergarten classroom of…

Infants begin to segment words from fluent speech during the same time period that they learn phonetic categories. Segmented words can provide a potentially useful cue for phonetic learning, yet accounts of phonetic category acquisition typically ignore the contexts in which sounds appear. We present two experiments to show that, contrary to the…

Children who start formal education in a second language may experience slower vocabulary growth in that language and subsequently experience disadvantages in literacy acquisition. The current study asked whether lexical specificity training can stimulate bilingual children's phonological awareness, which is considered to be a precursor to…

Second language (L2) learners of tone languages do not perceive and produce the different tones of the target language with equal ease. The most common explanation for these asymmetries is that acoustically salient tones are the easiest to learn. An alternative explanation is that tones are easiest to learn when they are highly frequent in the…

Speech production is inextricably linked to speech perception, yet they are usually investigated in isolation. In this study, we employed a verbal-repetition task to identify the neural substrates of speech processing with two ends active simultaneously using functional MRI. Subjects verbally repeated auditory stimuli containing an ambiguous vowel…

What is second language fluency? What is a foreign accent? Is it possible for an adult second language learner to speak fluently with a heavy accent or vice versa? What factors contribute to the perception of fluency and a foreign accent? What acoustic attributes correlate with the perception of fluency and a foreign accent? To answer these…