Can children tell how different a speaker's accent is from their own? In Experiment 1 (N = 84), four- and five-year-olds heard speakers with different accents and indicated where they thought each speaker lived relative to a reference point on a map that represented their current location. Five-year-olds generally placed speakers with stronger accents (as judged by adults) at more distant locations than speakers with weaker accents. In contrast, four-year-olds did not show differences in where they placed speakers with different accents. In Experiment 2 (N = 56), the same sentences were low-pass filtered so that only prosodic information remained. This time, children judged which of five possible aliens had produced each utterance, given a reference speaker. Children of both ages showed differences in which alien they chose based on accent, and generally rated speakers with foreign accents as more different from their native accent than speakers with regional accents. Together, the findings show that preschoolers perceive accent distance, that children may be sensitive to the distinction between foreign and regional accents, and that preschoolers likely use prosody to differentiate among accents.

Recent findings demonstrate a bilingual advantage for voice processing in children, but the mechanism supporting this advantage is unknown. Here we examined whether a bilingual advantage for voice processing is observed in adults and, if so, if it reflects enhanced pitch perception or inhibitory control. Voice processing was assessed for monolingual and bilingual adults using an associative learning identification task and a discrimination task in English (a familiar language) and French (an unfamiliar language). Participants also completed pitch perception, flanker, and auditory Stroop tasks. Voice processing was improved for the familiar compared to the unfamiliar language and reflected individual differences in pitch perception (both tasks) and inhibitory control (identification task). However, no bilingual advantage was observed for either voice task, suggesting that the bilingual advantage for voice processing becomes attenuated during maturation, with performance in adulthood reflecting knowledge of linguistic structure in addition to general auditory and inhibitory control abilities.

Substantial individual differences exist in regard to type and amount of experience with variable speech resulting from foreign or regional accents. Whereas prior experience helps with processing familiar accents, research on how experience with accented speech affects processing of unfamiliar accents is inconclusive, ranging from perceptual benefits to processing disadvantages. We examined how experience with accented speech modulates mono- and bilingual children's (mean age: 9;10) ease of speech comprehension for two unfamiliar accents in German, one foreign and one regional. More experience with regional accents helped children repeat sentences correctly in the regional condition and in the standard condition. More experience with foreign accents did not help in either accent condition. The results suggest that type and amount of accent experience co-determine processing ease of accented speech.

Listening to speech entails adapting to vast amounts of variability in the signal. The present study examined the relationship between flexibility for adaptation in a second language (L2) and robustness of L2 phonolexical representations. Phonolexical encoding and phonetic flexibility for German learners of English were assessed by means of a lexical decision task containing nonwords with sound substitutions and a distributional learning task, respectively. Performance was analyzed for an easy (/i/-/ɪ/) and a difficult contrast (/ɛ/-/æ/, where /æ/ does not exist in German). Results showed that for /i/-/ɪ/ listeners were quite accurate in lexical decision, and distributional learning consistently triggered shifts in categorization. For /ɛ/-/æ/, lexical decision performance was poor but individual participants’ scores related to performance in distributional learning: the better learners were in their lexical decision, the smaller their categorization shift. This suggests that, for difficult L2 contrasts, rigidity at the phonetic level relates to better lexical performance.

Spanish speakers tend to perceive an illusory [e] preceding word-initial [s]-consonant sequences, e.g., perceiving [stið] as [estið] (Cuetos, Hallé, Domínguez & Segui, 2011), but this illusion is weaker for Spanish speakers who know English, which lacks the illusion (Carlson, Goldrick, Blasingame & Fink, 2016). The present study aimed to shed light on why this occurs by assessing how a brief interval spent using English impacts performance in Spanish auditory discrimination and lexical decision. Late Spanish–English bilinguals’ pattern of responses largely matched that of monolinguals, but their response times revealed significant differences between monolinguals and bilinguals, and between bilinguals who had just completed tasks in English vs. Spanish. These results suggest that late bilinguals do not simply learn to perceive initial [s]-consonant sequences veridically, but that elements of both their phonotactic systems interact dynamically during speech perception, as listeners work to identify what it was they just heard.

In this article, I present a selective review of research on speech perception development and its relation to reference, word learning, and other aspects of language acquisition, focusing on the empirical and theoretical contributions that have come from my laboratory over the years. Discussed are the biases infants have at birth for processing speech, the mechanisms by which universal speech perception becomes attuned to the properties of the native language, and the extent to which changing speech perception sensitivities contribute to language learning. These issues are reviewed from the perspective of both monolingual and bilingual learning infants. Two foci will distinguish this from my previous reviews: first and foremost is the extent to which contrastive meaning and referential intent are not just shaped by, but also shape, changing speech perception sensitivities, and second is the extent to which infant speech perception is multisensory and its implications for both theory and methodology.

It has long been debated whether speech production and perception remain flexible in adulthood. The current study investigates the effects of language dominance switch in Galician new speakers (neofalantes) who are raised with Spanish as a primary language and learn Galician at an early age in a bilingual environment, but in adolescence, decide to switch to using Galician almost exclusively, for ideological reasons. Results showed that neofalantes pattern with Spanish-dominants in their perception and production of mid-vowel and fricative contrasts, but with Galician-dominants in their realisation of unstressed word-final vowels, a highly salient feature of Galician. These results are taken to suggest that despite early exposure to Galician, high motivation and almost exclusive Galician language use post-switch, there are limitations to what neofalantes can learn in both production and perception, but that the hybrid categories they appear to develop may function as opportunities to mark identity within a particular community.

School-age children's understanding of unfamiliar accents is not adult-like and the age at which this ability fully matures is unknown. To address this gap, eight- to fifteen-year-old children's (n = 74) understanding of native- and non-native-accented sentences in quiet and noise was assessed. Children's performance was adult-like by eleven to twelve years for the native accent in noise and by fourteen to fifteen years for the non-native accent in quiet. However, fourteen- to fifteen-year old's performance was not adult-like for the non-native accent in noise. Thus, adult-like comprehension of unfamiliar accents may require greater exposure to linguistic variability or additional cognitive–linguistic growth.

During the first two years of life, infants concurrently refine native-language speech categories and word learning skills. However, in the Switch Task, 14-month-olds do not detect minimal contrasts in a novel object–word pairing (Stager & Werker, 1997). We investigate whether presenting infants with acoustically salient contrasts (liquids) facilitates success in the Switch Task. The first two experiments demonstrate that acoustic differences boost infants’ detection of contrasts. However, infants cannot detect the contrast when the segments are digitally shortened. Thus, not all minimal contrasts are equally difficult, and the acoustic properties of a contrast matter in word learning.

This study investigates how second language (L2) listeners match an unexpected accented form to their stored form of a word. The phonetic-to-lexical mapping for L2 as compared to L1 regional varieties was examined with early and late Italian-L2 speakers who were all L1-Australian English speakers. AXB discrimination and lexical decision tasks were conducted in both languages, using unfamiliar regional accents that minimize (near-merge) consonant contrasts maintained in their own L1-L2 accents. Results reveal that in the L2, early bilinguals’ recognition of accented variants depended on their discrimination capacity. Late bilinguals, for whom the accented variants were not represented in their L2 lexicon, instead mapped standard and accented exemplars to the same lexical representations (i.e., dual mapping: Samuel & Larraza, 2015). By comparison, both groups showed the same broad accommodation to L1 accented variants. Results suggest qualitatively different yet similarly effective phonetic-to-lexical mapping strategies both for L2 versus L1 regional accents.

A bilingual advantage has been found in both cognitive and social tasks. In the current study, we examine whether there is a bilingual advantage in how children process information about who is talking (talker-voice information). Younger and older groups of monolingual and bilingual children completed the following talker-voice tasks with bilingual speakers: a discrimination task in English and German (an unfamiliar language), and a talker-voice learning task in which they learned to identify the voices of three unfamiliar speakers in English. Results revealed effects of age and bilingual status. Across the tasks, older children performed better than younger children and bilingual children performed better than monolingual children. Improved talker-voice processing by the bilingual children suggests that a bilingual advantage exists in a social aspect of speech perception, where the focus is not on processing the linguistic information in the signal, but instead on processing information about who is talking.

The effects of exposure to non-English heritage languages versus exposure to foreign-accented English during early childhood on language performances later in life were investigated. Three groups of young adult participants who differed in their early home language environment were examined on a series of linguistic tasks. Results showed that people who were mostly exposed to accented English in the early home environment are more native-like in various aspects of English language performance than those who were mostly exposed to their non-English heritage language, including vocabulary, pronunciation, and processing of certain types of speech stimuli. Early and extended exposure to accented speech, however, does not appear to enhance the ability to perceive foreign accents in general, and may in fact produce a disadvantage when listening to unfamiliar accents. These findings provide some initial insight into the consequences of migrant parents choosing to speak one language over the other with their children.

Monolingual listeners continuously predict upcoming information. Here, we tested whether predictive language processing occurs to the same extent when bilinguals listen to their native language vs. a non-native language. Additionally, we tested whether bilinguals use prediction to the same extent as monolinguals. Dutch–English bilinguals and English monolinguals listened to constraining and neutral sentences in Dutch (bilinguals only) and in English, and viewed target and distractor pictures on a display while their eye movements were measured. There was a bias of fixations towards the target object in the constraining condition, relative to the neutral condition, before information from the target word could affect fixations. This prediction effect occurred to the same extent in native processing by bilinguals and monolinguals, but also in non-native processing. This indicates that unbalanced, proficient bilinguals can quickly use semantic information during listening to predict upcoming referents to the same extent in both of their languages.

This special issue began as a conference on Bilingual and Multilingual Interaction at Bangor University in 2012. The papers collected here all have novel elements, either because of their innovative methods, their unusual data, or their unexpected findings. They present findings from studies of bilinguals speaking six different pairs of languages, and use a range of methods including experiments, naturalistic observation and auditory judgment data. Despite the differences in subject matter and methodological approaches, all the papers demonstrate that bilinguals draw on resources which are different from those of monolinguals. They show that the two languages spoken by bilinguals have clearly discernible effects on one another, and that these effects can potentially be enhancing. Future research will no doubt build on the studies presented here and extend our understanding of cross-language effects in bilingual production and comprehension.

This paper examines the ability of bilingual infants who were learning Dutch and another non-tone language to discriminate tonal contrasts. All infants from 5 to 18 months of age succeeded in discriminating a tonal contrast of Mandarin Chinese (Tone 1 versus Tone 4) and showed a U-shaped pattern when facing a less acoustically salient manipulated version (contracted) of the aforementioned contrast. Specifically, infants showed initial sensitivity to the contracted contrast during their early months, followed by a loss of sensitivity at the stage where tonal perceptual reorganization typically occurs, and a sensitivity rebound by the end of the first year after birth. Compared to a previous studying of ours testing monolingual Dutch infants (Liu & Kager, 2014), the discrimination patterns of bilingual infants revealed both similarities and differences. On one hand, as with monolinguals, non-tone-learning bilingual infants’ tonal perception presented plasticity influenced by contrast acoustic salience along the trajectory of perceptual reorganization; as well as a general U-shaped perceptual pattern when discriminating non-native tones. On the other hand, bilingual infants appeared to regain sensitivity to the contracted tonal contrast at an earlier age (11–12 months) in comparison with monolinguals infants (17–18 months). We provide several explanations, stemming from the simultaneous exposure to two languages, to account for the 6-month bilingual perceptual plasticity from linguistic and cognitive perspectives. The overall outcomes of the study offer insights into the infant perceptual reorganization and language development trajectory, expand on the differences between monolingual and bilingual language development, and broaden our understanding of the influence of bilingual exposure to the perception of non-native contrasts in infancy from linguistic and cognitive perspectives.

This review examines the convergence of recent developments in the fields of language and literacy development and, in particular, developments relating phonological development to both language and reading development. It begins by examining the issue of how children represent spoken words. In particular, it presents recent work arguing that, throughout early and even middle childhood, children’s representations of spoken words are reorganised as sequences of phonemes. The second section examines poor readers’ phonologicol recoding difficulties and, in particular, the contribution of phonological awareness to early reading success. This section includes an overview of phonologicol awareness training studies in “at-risk” preschool and kindergarten children. The final section examines phonologicol processing difficulties as a common underlying cause of reading dificulties.This section provides a theoretical context for practitioners to understand diverse findings relating performance on a wide range of tasks to children’s reading achievement.

Word-initial /s/-consonant clusters do not occur in Spanish. Confronted with such sequences (e.g., in loanwords), Spanish speakers tend to perceive an illusory initial /e/, ‘repairing’ the illicit sequence. In two experiments, both conducted in Spanish with Spanish-sounding nonwords, we ask whether knowledge of English, which has no restriction against this sound sequence, weakens this pattern of perceptual repair in fluent Spanish–English bilinguals, and whether the effects of English depend on language dominance. In both identification and discrimination tasks, bilinguals exhibited weaker perceptual repair effects relative to Spanish monolinguals. This was true even for bilinguals dominant in Spanish, though the weakening was more pronounced for English-dominant bilinguals. These results show that conflicting phonotactic systems can jointly influence bilinguals’ perceptual repair of the acoustic signal in the more restrictive language, even when it is the bilingual's dominant language, suggesting a degree of integration and mutual influence of knowledge between both their languages.

This study examined behavioral and neurophysiological indices of discrimination of an English vowel contrast [ɪ–ɛ] by early and late bilingual Spanish–English speakers, compared to monolingual English speakers. Electrophysiological measures (Mismatched Negativity – MMN) and behavioral measures (AX discrimination and forced-choice identification) were employed to examine perception of a nine-step vowel continuum, re-synthesized from natural tokens. Results revealed that (i) both monolingual and early bilinguals showed similar behavioral perception while late bilinguals performed more poorly on all behavioral tasks; and (ii) monolinguals showed robust evidence of discrimination (MMN) at a pre-attentive level that was significantly larger than found for either early or late bilinguals. These findings suggested that early input of English vowels to bilinguals did not necessarily lead to robust, automatic processing, as measured at a more attention-independent neural level; but earlier experience with a second language allowed for native-like speech perception measured with behavioral tasks.

Motor theories of perception posit that motor information is necessary for successful recognition of actions. Perhaps the most well known of this class of proposals is the motor theory of speech perception, which argues that speech recognition is fundamentally a process of identifying the articulatory gestures (i.e. motor representations) that were used to produce the speech signal. Here we review neuropsychological evidence from patients with damage to the motor system, in the context of motor theories of perception applied to both manual actions and speech. Motor theories of perception predict that patients with motor impairments will have impairments for action recognition. Contrary to that prediction, the available neuropsychological evidence indicates that recognition can be spared despite profound impairments to production. These data falsify strong forms of the motor theory of perception, and frame new questions about the dynamical interactions that govern how information is exchanged between input and output systems.