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Singing is socially important but constrains voice acoustics, potentially masking certain aspects of vocal identity. Little is known about how well listeners extract talker details from sung speech or identify talkers across the sung and spoken modalities. Here, listeners (n = 149) were trained to recognize sung or spoken voices and then tested on their identification of these voices in both modalities. Learning vocal identities was initially easier through speech than song. At test, cross-modality voice recognition was above chance, but weaker than within-modality recognition. We conclude that talker information is accessible in sung speech, despite acoustic constraints in song., (© 2024 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).)

Child speech deviates from adult speech in predictable ways. Are listeners who routinely interact with children implicitly aware of these systematic deviations, and thereby better at understanding children? Or do idiosyncratic differences in how children pronounce words overwhelm these systematic deviations? In Experiment 1, we use a speech-in-noise transcription task to test who "speaks kid" among four listener groups: undergraduates ( n = 48), mothers of young children ( n = 48), early childhood educators ( n = 48), and speech-language pathologists (SLPs; n = 48). All listeners transcribed speech by typically developing children and adults. In Experiment 2, we use a similar task to test an additional group of mothers ( n = 50) on how intelligible they found their own child versus another child. Contrary to previous claims, we find no evidence for an experience-based general child speech intelligibility advantage. However, we do find that mothers understand their own child best. We also observe a general task advantage by SLPs. Our findings demonstrate that routine (and even extensive) exposure to children may not make all children more intelligible, but that it may instead make particular children one has experience with more intelligible. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

When university students are asked to rate their instructors, their evaluations are often influenced by the demographic characteristics of the instructor-such as the instructor's race, gender, or language background. These influences can manifest in unfair systematic biases against particular groups of teachers and hamper movements to promote diversity in higher education. When and how do these biases develop? Here, we begin to address these questions by examining children's sociolinguistic biases against teachers who speak with different accents. To do this, we presented 5-year-old Canadian English-speaking children with pairs of adult talkers. Children were asked to select "who they'd like to be their teacher" then they rated "how good of a teacher" they thought each talker would be on a 5-point scale. In each trial, one talker spoke in the locally dominant variety of Canadian English, and the other spoke in a different accent. Children strongly preferred Canadian-accented teachers over teachers who spoke with non-native (i.e., French or Dutch) accents, but also demonstrated a preference for Canadian teachers over teachers who spoke with non-local regional accents (i.e., Australian or British). In line with the binary choice data, children rated the Canadian talkers more favourably. The relationship between the gender of the teacher and the gender of the child also impacted ratings. This work demonstrates that even at the onset of formal education, children may already exhibit signs of accent-based biases. We discuss these findings in relation to the growing literature on implicit bias in higher education.

Purpose: We compare teens' and adults' imitation of sentences with shortened and lengthened voice onset time (VOT), in order to test whether purported age-based advantages in phonetic acquisition may be due to differences in imitative ability., Method: Teens ( M age = 13, n = 39) and adults ( n = 31) completed an explicit imitation and discrimination task on pairs of sentences characterized by canonical and manipulated (shortened or lengthened) VOT. We assessed extent of imitation using two acoustic metrics (ΔVOT and Proximity), accuracy on the discrimination task, and correlations between imitation and perception., Results: Both age groups modified VOT when imitating stimuli with both lengthened and shortened VOT. Adults, however, showed significantly more lengthening than teens (i.e., higher ΔVOT), as well as VOT values that were slightly but significantly closer to the target stimulus values (i.e., lower proximity). Both age groups showed above-chance discrimination accuracy, and a significant relationship between individual perception and production performance was found for lengthened-VOT sentences., Conclusions: We found no evidence that teens have a greater imitative ability than adults; in fact, adults showed significantly more imitation based on both acoustic metrics. Both age groups showed robust imitation of VOT manipulations in both directions, in contrast to previous work showing lack of imitation for shortened VOT. Extent of imitation was predicted by individual perceptual performance, but only to a limited degree, underscoring the importance of other factors in explaining individual variation in imitative ability.

One of the great mysteries of language acquisition is how children cope with variation in their input. If one parent says pah-tah-to and the other parent says pah-tay-to, how does this affect a child's speech processing development? Past research suggests variableinput may have negative effects on the efficiency of multi-accent children'swordrecognition, leading to slower word recognition compared to mono-accent children, and even failure to recognize words in their parent's non-dominant accent. Here, were-examine speed ofwordrecognitionina large sample of Dutch-learning 24-month-olds (n = 96) who receive routine exposure to one versus two varieties of their native language.. We conclude that multi-accent children are equipped to flexibly adapt to their variable speech input, and show no language delay at 24 months of age. Contrary to earlier reports, we find no evidence that exposure to multiple varieties has long-lasting detrimental effects ontoddler's wordrecognition efficiency., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Observations by sociolinguists suggest that when children relocate to a new community, they rapidly learn to imitate their peers, adopting the new local accent faster and more effectively than adults. However, few well-controlled laboratory experiments have been conducted comparing speech or accent imitation across ages. Here, we investigated Canadian English-speaking children's and adults' imitation of three model speakers: a Canadian English talker, an Australian English talker, and a non-native Mandarin English talker who learned English later in life. The speech of all three talkers was manipulated to have elongated voice onset time (VOT) on word initial stop consonants. The dependent measure was how much participants would lengthen their VOTs after exposure to one of the talkers in two paradigms: delayed shadowing (Experiment 1) and immediate shadowing (Experiment 2). We predicted that overall children would show more imitation than adults, particularly when imitating the Canadian English talker, given previous work on children's social preferences. Although we did not observe age differences in either study, when shadowing was immediate, we found that imitation was influenced by the accent of the speaker, but not in the manner we predicted: both age groups imitated the Mandarin-accented model more strongly than the Canadian model. When shadowing was delayed, we observed no evidence of imitation. We discuss our findings in light of other recent work, and conclude that the development of speech imitation is an area ripe for further investigation.

Recent work has shown that exposure to multiple languages affects nonlinguistic processing of speech during infancy. Specifically, Fecher and Johnson found that bilingual 9-month-olds outperformed their monolingual peers in a face-voice matching task in an unfamiliar language [Developmental Science (2019a), 22(4), e12778]. What factors were driving this effect? That is, was this finding truly reflective of a bilingual advantage specific to talker processing, or did the study demonstrate a general cognitive advantage in bilingual infants? Here, we revisited this question by testing bilingual and monolingual 9-month-olds (N = 48) on their ability to associate previously unknown voices with animated cartoon characters. In comparison with earlier work, where infants were presented with characters speaking an unfamiliar language (Spanish), the characters in this study spoke a language familiar to both groups of infants (English). Critically, we found that the monolingual and bilingual infants learned the face-voice pairings equally well when they were tested on the familiar language. We conclude that whereas bilingual infants are skilled at recognizing talkers regardless of the language spoken by the talkers, monolingual infants succeed at talker recognition in a familiar language only. These results begin to clarify the underlying nature of the talker recognition benefit previously reported for bilingual infants., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Past research suggests listeners treat disfluencies as informative cues during spoken language processing. For example, studies have shown that child and younger adult listeners use filled pauses to rapidly anticipate discourse-new objects. The present study explores whether older adults show a similar pattern, or if this ability is reduced in light of age-related declines in language and cognitive abilities. The study also examines whether the processing of disfluencies differs depending on the talker's age. Stereotyped ideas about older adults' speech could lead listeners to treat disfluencies as uninformative, similar to the way in which listeners react to disfluencies produced by non-native speakers or individuals with a cognitive disorder. Experiment 1 used eye tracking to capture younger and older listeners' real-time reactions to filled pauses produced by younger and older talkers. On critical trials, participants followed fluent or disfluent instructions referring to either discourse-given or discourse-new objects. Younger and older listeners treated filled pauses produced by both younger and older talkers as cues for reference to discourse-new objects despite holding stereotypes regarding older adults' speech. Experiment 2 further explored listeners' biased judgments of talkers' fluency, using auditory materials from Experiment 1. Speech produced by an older talker was rated as more disfluent and slower than a younger talker even though these features were matched across recordings. Together, the findings demonstrate (a) older listeners' effective use of disfluency cues in real-time processing and (b) that listeners treat both older and younger talkers' disfluencies as informative despite biased perceptions regarding older talkers' speech. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

The existence of the Language Familiarity Effect (LFE), where talkers of a familiar language are easier to identify than talkers of an unfamiliar language, is well-documented and uncontroversial. However, a closely related phenomenon known as the Other Accent Effect (OAE), where accented talkers are more difficult to recognize, is less well understood. There are several possible explanations for why the OAE exists, but to date, little data exist to adjudicate differences between them. Here, we begin to address this issue by directly comparing listeners' recognition of talkers who speak in different types of accents, and by examining both the LFE and OAE in the same set of listeners. Specifically, Canadian English listeners were tested on their ability to recognize talkers within four types of voice line-ups: Canadian English talkers, Australian English talkers, Mandarin-accented English talkers, and Mandarin talkers. We predicted that the OAE would be present for talkers of Mandarin-accented English but not for talkers of Australian English-which is precisely what we observed. We also observed a disconnect between listeners' confidence and performance across different types of accents; that is, listeners performed equally poorly with Mandarin and Mandarin-accented talkers, but they were more confident with their performance with the latter group of talkers. The present findings set the stage for further investigation into the nature of the OAE by exploring a range of potential explanations for the effect, and introducing important implications for forensic scientists' evaluation of ear witness testimony., (© 2021 Cognitive Science Society LLC.)

This work explores the relationship between phonetic and perceptual metrics for convergence in shadowed productions by adults and 6-year-old children by isolating the role of voice onset time (VOT) in listeners' similarity judgments. Results show a small but independent role for VOT: listeners were less likely to identify shadowed tokens as more similar to the model when natural VOT convergence present in the stimulus set had been artificially removed (experiments 1 and 2). However, VOT equivalence alone, when accompanied by naturally occurring variation along other dimensions, was not sufficient to drive listeners' judgments of similarity (experiment 3).

Infants struggle to understand familiar words spoken in unfamiliar accents. Here, we examine whether accent exposure facilitates accent-specific adaptation. Two types of pre-exposure were examined: video-based (i.e., listening to pre-recorded stories; Experiment 1) and live interaction (reading books with an experimenter; Experiments 2 and 3). After video-based exposure, Canadian English-learning 15- to 18-month-olds failed to recognize familiar words spoken in an unfamiliar accent. However, after face-to-face interaction with a Mandarin-accented talker, infants showed enhanced recognition for words produced in Mandarin English compared to Australian English. Infants with live exposure to an Australian talker were not similarly facilitated, perhaps due to the lower vocabulary scores of the infants assigned to the Australian exposure condition. Thus, live exposure can facilitate accent adaptation, but this ability is fragile in young infants and is likely influenced by vocabulary size and the specific mapping between the speaker and the listener's phonological system.

Previous studies have shown that talker recognition by young children continues to improve into late childhood. But why might this be the case? Are children's gradually improving talker recognition abilities driven primarily by general maturational factors in the cognitive or perceptual domain (general maturation hypothesis), or are these improvements primarily linked to children's increasingly sophisticated linguistic knowledge (language attunement hypothesis)? In the current study, we addressed this question by testing monolingual English-speaking 5- and 6-year-olds (N = 80) on their ability to recognize talkers in a familiar language (i.e., English) and in an unfamiliar language (i.e., Spanish) using a "voice lineup" talker recognition task. We predicted two alternative outcomes. According to the general maturation hypothesis, we should see improvements in talker recognition for both the familiar and unfamiliar languages as children grow older. According to the language attunement hypothesis, however, we should see developmental improvements in talker recognition for the familiar language only. Our findings suggest that early developmental improvements in talker recognition are limited to familiar languages, highlighting the potential central role of language-specific knowledge in talker recognition., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Human adults rely on both acoustic and linguistic information to identify adult talkers. Assuming favorable conditions, adult listeners recognize other adults fairly accurately and quickly. But how well can adult listeners recognize child talkers, whose speech productions often differ dramatically from adult speech productions? Although adult talker recognition has been heavily studied, only one study to date has directly compared the recognition of unfamiliar adult and child talkers [Creel and Jimenez (2012). J. Exp. Child Psychol. 113(4), 487-509]. Therefore, the current study revisits this question with a much larger and younger sample of child talkers (N = 20); performance with adult talkers (N = 20) was also tested to provide a baseline. In Experiment 1, adults successfully distinguished between adult talkers in an AX discrimination task but performed much worse with child talkers. In Experiment 2, adults were slower and less accurate at learning to identify child talkers than adult talkers in a training-identification task. Finally, in Experiment 3, adults failed to improve at identifying child talkers after three days of training with numerous child voices. Taken together, these findings reveal a sizable difference in adults' ability to recognize child versus adult talkers. Possible explanations and implications for understanding human talker recognition are discussed.

Contemporary models of adult speech perception acknowledge that the processing of linguistic and nonlinguistic aspects of the speech signal are interdependent. But when in development does this interdependence first emerge? In the adult literature, one way to demonstrate this relationship has been to examine how language experience affects talker identification. Thus, in this study, 4- to 5-month-old infants (N = 96) were tested on their ability to tell apart talkers in a familiar language (English) compared to unfamiliar languages (Polish or Spanish). Infants readily distinguished between talkers in the familiar language but not in the unfamiliar languages, supporting the hypothesis that the integrated processing of linguistic and nonlinguistic information in speech is early emerging and robust., (© 2019 Society for Research in Child Development.)

Bilingual and monolingual infants differ in how they process linguistic aspects of the speech signal. But do they also differ in how they process non-linguistic aspects of speech, such as who is talking? Here, we addressed this question by testing Canadian monolingual and bilingual 9-month-olds on their ability to learn to identify native Spanish-speaking females in a face-voice matching task. Importantly, neither group was familiar with Spanish prior to participating in the study. In line with our predictions, bilinguals succeeded in learning the face-voice pairings, whereas monolinguals did not. We consider multiple explanations for this finding, including the possibility that simultaneous bilingualism enhances perceptual attentiveness to talker-specific speech cues in infancy (even in unfamiliar languages), and that early bilingualism delays perceptual narrowing to language-specific talker recognition cues. This work represents the first evidence that multilingualism in infancy affects the processing of non-linguistic aspects of the speech signal, such as talker identity., (© 2018 John Wiley & Sons Ltd.)

Language and accent strongly influence the formation of social groups. By five years of age, children already show strong social preferences for peers who speak their native language with a familiar accent (Kinzler, Shutts, DeJesus, & Spelke, 2009). However, little is known about the factors that modulate the strength and direction of children's accent-based group preferences. In three experiments, we examine the development of accent-based friendship preferences in children growing up in Toronto, one of the world's most linguistically and culturally diverse cities. We hypothesized that the speaker's type of accent and the amount of accent exposure children experienced in their everyday lives would modulate their preferences in a friend selection task. Despite literature suggesting that exposure leads to greater acceptance (Allport, 1954), we find no evidence that routine exposure to different accents leads to greater acceptance of unfamiliarly accented speakers. Children still showed strong preferences for peers who spoke with the locally dominant accent, despite growing up in a linguistically diverse community. However, children's preference for Canadian-accented in-group members was stronger when they were paired with non native (Korean-accented) speakers compared to when they were paired with regional (British-accented) speakers. We propose that children's ability to perceptually distinguish between accents may have contributed to this difference. Children showed stronger preferences for in-group members when the difference between accents was easier to perceive. Overall, our findings suggest that although the strength of accent-based social preferences can be modulated by the type of accent, these preferences still persist in the face of significant diversity in children's accent exposure. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Adults recognize talkers better when the talkers speak a familiar language than when they speak an unfamiliar language. This language familiarity effect (LFE) demonstrates the inseparable nature of linguistic and indexical information in adult spoken language processing. Relatively little is known about children's integration of linguistic and indexical information in speech. For example, to date, only one study has explored the LFE in infants. Here, we sought to better understand the maturation of speech processing abilities in infants by replicating this earlier study using a more stringent experimental design (eliminating a potential voice-language confound), a different test population (English- rather than Dutch-learning infants), and a new language pairing (English vs. Polish rather than Dutch vs. Italian or Japanese). Furthermore, we explored the language exposure conditions required for infants to develop an LFE for a formerly unfamiliar language. We hypothesized based on previous studies (including the perceptual narrowing literature) that infants might develop an LFE more readily than would adults. Although our findings replicate those of the earlier study-demonstrating that the LFE is robust in 7.5-month-olds-we found no evidence that infants need less language exposure than do adults to develop an LFE. We concluded that both infants and adults need extensive (potentially live) exposure to an unfamiliar language before talker identification in that language improves. Moreover, our study suggests that the LFE is likely rooted in early emerging phonology rather than shared lexical knowledge and that infants already closely resemble adults in their processing of linguistic and indexical information. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

How do children represent words? If lexical representations are based on encoding the indexical characteristics of frequently-heard speakers, this predicts that speakers like a child's own mother should be best understood. Alternatively, if they are based on the child's own motor productions, this predicts an own-voice advantage in word recognition. Here, we address this question by presenting 2.5-year-olds with recordings of their own voice, another child's voice, their own mother's voice, and another mother's voice in a child-friendly eye-tracking procedure. No own-voice or own-mother advantage was observed. Rather, children uniformly performed better on adult voices than child voices, even performing better for unfamiliar adult voices than own voices. We conclude that children represent words not in the form of own-voice motor codes or frequently heard speakers, but on the basis of adult speech targets., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Talker recognition is a language-dependent process, with listeners recognizing talkers better when the talkers speak a familiar versus an unfamiliar language. This language familiarity effect (LFE) is firmly established in adults, but its developmental trajectory in children is not well understood. Some evidence suggests that the effect already exists in infancy, but little is known about how it unfolds in childhood. The present study explored whether the strength of the LFE increases in early childhood. Adults and children were tested in their native language and a foreign language using a "same-different" talker discrimination task and a "voice line-up" talker recognition task. Results showed that adults and 6-year-olds, but not 5-year-olds, exhibit a robust LFE, suggesting that the effect strengthens as children's language competence increases. For both adults and older children, the emergence of an LFE moreover appeared to be task-dependent. This study contributes to a better understanding of how children develop mature talker recognition abilities and when children's processing of indexical and linguistic information in speech approaches adult-like levels. Furthermore, the findings reported here contribute to the debates regarding the origins of the LFE-a hallmark of adult talker recognition.

Talkers are recognized more accurately if they are speaking the listeners' native language rather than an unfamiliar language. This "language familiarity effect" has been shown not to depend upon comprehension and must instead involve language sound patterns. We further examine the level of sound-pattern processing involved, by comparing talker recognition in foreign languages versus two varieties of English, by (a) English speakers of one variety, (b) English speakers of the other variety, and (c) non-native listeners (more familiar with one of the varieties). All listener groups performed better with native than foreign speech, but no effect of language variety appeared: Native listeners discriminated talkers equally well in each, with the native variety never outdoing the other variety, and non-native listeners discriminated talkers equally poorly in each, irrespective of the variety's familiarity. The results suggest that this talker recognition effect rests not on simple familiarity, but on an abstract level of phonological processing., (Copyright © 2017 Cognitive Science Society, Inc.)

Although studies investigating language abilities in young children exposed to more than one language have become common, there is still surprisingly little research examining language development in children exposed to more than one accent. Here, we report two looking-while-listening experiments examining the impact of routine home exposure to multiple accents on 2-year-olds' word recognition abilities. In Experiment 1, we found that monolingual English-learning 24-month-olds who routinely receive exposure to both Canadian English and a non-native variant of English are less efficient in their recognition of familiar words spoken in Canadian English than monolingual English-learning 24-month-olds who hear only Canadian English at home. In Experiment 2, we found that by 34months of age all children recognize words equally quickly regardless of their accent exposure at home. We conclude that monolingual toddlers in some locations may form a less homogeneous population than past work has assumed, a factor that should be considered when drawing generalizations about language development across different populations., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)

Early language input is far from uniform, even among children learning the same language. For instance, while some children are exposed to a single accent in their linguistic environment, others have routine exposure to multiple accents. Nonetheless, few studies have taken this into account when examining word recognition, and none has examined this issue in infants prior to the emergence of phonological constancy (∼18 months). This study demonstrates that daily exposure to multiple accents strongly impacts infants' performance in a laboratory word form recognition task. Accent variability in the input thus needs to be carefully considered when studying speech development.

Sensitivity to noncontrastive subphonemic detail plays an important role in adult speech processing, but little is known about children's use of this information during online word recognition. In two eye-tracking experiments, we investigate 2-year-olds' sensitivity to a specific type of subphonemic detail: coarticulatory mismatch. In Experiment 1, toddlers viewed images of familiar objects (e.g., a boat and a book) while hearing labels containing appropriate or inappropriate coarticulation. Inappropriate coarticulation was created by cross-splicing the coda of the target word onto the onset of another word that shared the same onset and nucleus (e.g., to create boat, the final consonant of boat was cross-spliced onto the initial CV of bone). We tested 24-month-olds and 29-month-olds in this paradigm. Both age groups behaved similarly, readily detecting the inappropriate coarticulation (i.e., showing better recognition of identity-spliced than cross-spliced items). In Experiment 2, we asked how children's sensitivity to subphonemic mismatch compared to their sensitivity to phonemic mismatch. Twenty-nine-month-olds were presented with targets that contained either a phonemic (e.g., the final consonant of boat was spliced onto the initial CV of bait) or a subphonemic mismatch (e.g., the final consonant of boat was spliced onto the initial CV of bone). Here, the subphonemic (coarticulatory) mismatch was not nearly as disruptive to children's word recognition as a phonemic mismatch. Taken together, our findings support the view that 2-year-olds, like adults, use subphonemic information to optimize online word recognition.

Adults are generally adept at recognizing familiar words in unfamiliar accents. However, studies testing young children’s abilities to cope with accent-related variation in the speech signal have generated mixed results, with some work emphasizing toddlers’ early competence and other work focusing more on their long-lasting difficulties in this domain. Here, we set out to unify these two perspectives and propose that task demands may play a crucial role in children’s recognition of accented words. To this end, Canadian-English-learning 28-month-olds’ looks to images on a screen were recorded while they were presented with a Scottish-accented speaker instructing them to find a depicted target object. To examine the effect of task demands, both local sentence context and prior accent exposure were manipulated. Overall, Canadian toddlers were found to recognize Scottish-accented words successfully, showing above-chance performance in the identification of words produced in an unfamiliar accent, even when target labels were presented in isolation. However, word recognition was considerably more robust when target words were presented in sentence context. Prior exposure to the unfamiliar Scottish accent in the laboratory did not modulate children’s performance in this task. Taken together, these findings suggest that at least some task-related factors can affect children’s recognition of accented words. Understanding unfamiliar accents, like understanding familiar accents, is thus not an isolated skill but, rather, is susceptible to contextual circumstances. Future models of spoken language processing in toddlerhood should incorporate these early effects of task demands.

Analyses of caregiver-child communication suggest that an adult tends to highlight objects in a child's visual scene by moving them in a manner that is temporally aligned with the adult's speech productions. Here, we used the looking-while-listening paradigm to examine whether 25-month-olds use audiovisual temporal alignment to disambiguate and learn novel word-referent mappings in a difficult word-learning task. Videos of two equally interesting and animated novel objects were simultaneously presented to children, but the movement of only one of the objects was aligned with an accompanying object-labeling audio track. No social cues (e.g., pointing, eye gaze, touch) were available to the children because the speaker was edited out of the videos. Immediately afterward, toddlers were presented with still images of the two objects and asked to look at one or the other. Toddlers looked reliably longer to the labeled object, demonstrating their acquisition of the novel word-referent mapping. A control condition showed that children's performance was not solely due to the single unambiguous labeling that had occurred at experiment onset. We conclude that the temporal link between a speaker's utterances and the motion they imposed on the referent object helps toddlers to deduce a speaker's intended reference in a difficult word-learning scenario. In combination with our previous work, these findings suggest that intersensory redundancy is a source of information used by language users of all ages. That is, intersensory redundancy is not just a word-learning tool used by young infants., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Although adults rapidly adjust to accented speakers' pronunciation of words, young children appear to struggle when confronted with unfamiliar variants of their native language (e.g., American English-learning 15-month-olds cannot recognize familiar words spoken in Jamaican English; Best et al., 2009). It is currently unclear, however, why this is the case, or how infants overcome this apparent inability. Here, we begin to address these crucial questions. Experiments 1 and 2 confirm with a new population that infants are initially unable to recognize familiar words produced in unfamiliar accents. That is, Canadian English-learning infants cannot recognize familiar words spoken in Australian English until they near their second birthday. However, Experiments 3 and 4 show that this early inability to recognize accented words can readily be overcome when infants are exposed to a story read in the unfamiliar accent prior to test. Importantly, this adaptation only occurs when the story is highly familiar, consistent with the idea that top-down lexical feedback may enable the adaptation process. We conclude that infants, like adults, have the cognitive capacity to rapidly deduce the mapping between their own and an unfamiliar variant of their native language. Thus, the essential machinery underlying spoken language communication is in place much earlier than previous studies have suggested.

An audio and video corpus of speech addressed to 28 11-month-olds is described. The corpus allows comparisons between adult speech directed toward infants, familiar adults, and unfamiliar adult addressees as well as of caregivers' word teaching strategies across word classes. Summary data show that infant-directed speech differed more from speech to unfamiliar than familiar adults, that word teaching strategies for nominals versus verbs and adjectives differed, that mothers mostly addressed infants with multi-word utterances, and that infants' vocabulary size was unrelated to speech rate, but correlated positively with predominance of continuous caregiver speech (not of isolated words) in the input.

Using a referent detection paradigm, we examined whether listeners can determine the object speakers are referring to by using the temporal alignment between the motion speakers impose on objects and their labeling utterances. Stimuli were created by videotaping speakers labeling a novel creature. Without being explicitly instructed to do so, speakers moved the creature during labeling. Trajectories of these motions were used to animate photographs of the creature. Participants in subsequent perception studies heard these labeling utterances while seeing side-by-side animations of two identical creatures in which only the target creature moved as originally intended by the speaker. Using the cross-modal temporal relationship between speech and referent motion, participants identified which creature the speaker was labeling, even when the labeling utterances were low-pass filtered to remove their semantic content or replaced by tone analogues. However, when the prosodic structure was eliminated by reversing the speech signal, participants no longer detected the referent as readily. These results provide strong support for a prosodic cross-modal alignment hypothesis. Speakers produce a perceptible link between the motion they impose upon a referent and the prosodic structure of their speech, and listeners readily use this prosodic cross-modal relationship to resolve referential ambiguity in word-learning situations.

Purpose: To examine the possibility that early signal-to-word form mapping capabilities are robust enough to handle substantial indexical variation in the realization of words., Method: Two groups of 7.5-month-olds were tested with the Headturn Preference Procedure. Half of the infants were exposed to words embedded in passages spoken by their mothers and tested on lists of trained and novel isolated words spoken by their fathers. The other half of the infants were yoked pairs listening to unfamiliar speakers., Results: In the test phase, infants listened longer to trained than to novel words, indicating that they successfully segmented the words from the passages. This result was not modulated by infants' familiarity with the speaker., Conclusions: Under more naturalistic listening conditions, 7.5-month-olds exhibit the ability to recognize words in the face of substantial indexical variation regardless of whether speakers are familiar. This suggests that early word representations are, at least to some extent, independent of the speaker's gender and may reflect sophisticated abstraction capabilities on the part of the infants, which would render extreme episodic models of early speech perception untenable. Additional research using similarly ecologically valid testing methods is called for to elucidate the precise nature of early word representations.

A visual fixation study tested whether 7-month-olds can discriminate between different talkers. The infants were first habituated to talkers producing sentences in either a familiar or unfamiliar language, then heard test sentences from previously unheard speakers, either in the language used for habituation, or in another language. When the language at test mismatched that in habituation, infants always noticed the change. When language remained constant and only talker altered, however, infants detected the change only if the language was the native tongue. Adult listeners with a different native tongue from the infants did not reproduce the discriminability patterns shown by the infants, and infants detected neither voice nor language changes in reversed speech; both these results argue against explanation of the native-language voice discrimination in terms of acoustic properties of the stimuli. The ability to identify talkers is, like many other perceptual abilities, strongly influenced by early life experience., (© 2011 Blackwell Publishing Ltd.)

The nature of children's early lexical processing was investigated by asking what information 36-month-olds access and use when instructed to find a known but absent referent. Children readily retrieved stored knowledge about characteristic color, i.e., when asked to find an object with a typical color (e.g., strawberry), children tended to fixate more upon an object that had the same (e.g., red plane) as opposed to a different (e.g., yellow plane) color. They did so regardless of the fact that they had plenty of time to recognize the pictures for what they are, i.e., planes and not strawberries. These data represent the first demonstration that language-mediated shifts of overt attention in young children can be driven by individual stored visual attributes of known words that mismatch on most other dimensions. The finding suggests that lexical processing and overt attention are strongly linked from an early age.

Past research has demonstrated that infants can rapidly extract syllable distribution information from an artificial language and use this knowledge to infer likely word boundaries in speech. However, artificial languages are extremely simplified with respect to natural language. In this study, we ask whether infants' ability to track transitional probabilities between syllables in an artificial language can scale up to the challenge of natural language. We do so by testing both 5.5- and 8-month-olds' ability to segment an artificial language containing four words of uniform length (all CVCV) or four words of varying length (two CVCV, two CVCVCV). The transitional probability cues to word boundaries were held equal across the two languages. Both age groups segmented the language containing words of uniform length, demonstrating that even 5.5-month-olds are extremely sensitive to the conditional probabilities in their environment. However, neither age group succeeded in segmenting the language containing words of varying length, despite the fact that the transitional probability cues defining word boundaries were equally strong in the two languages. We conclude that infants' statistical learning abilities may not be as robust as earlier studies have suggested.

English-learning 7.5-month-olds are heavily biased to perceive stressed syllables as word onsets. By 11 months, however, infants begin segmenting non-initially stressed words from speech. Using the same artificial language methodology as Johnson and Jusczyk (2001), we explored the possibility that the emergence of this ability is linked to a decreased reliance on prosodic cues to word boundaries accompanied by an increased reliance on syllable distribution cues. In a baseline study, where only statistical cues to word boundaries were present, infants exhibited a familiarity preference for statistical words. When conflicting stress cues were added to the speech stream, infants exhibited a familiarity preference for stress as opposed to statistical words. This was interpreted as evidence that 11-month-olds weight stress cues to word boundaries more heavily than statistical cues. Experiment 2 further investigated these results with a language containing convergent cues to word boundaries. The results of Experiment 2 were not conclusive. A third experiment using new stimuli and a different experimental design supported the conclusion that 11-month-olds rely more heavily on prosodic than statistical cues to word boundaries. We conclude that the emergence of the ability to segment non-initially stressed words from speech is not likely to be tied to an increased reliance on syllable distribution cues relative to stress cues, but instead may emerge due to an increased reliance on and integration of a broad array of segmentation cues.

The Headturn Preference Paradigm was used to examine infants' use of prosodically conditioned acoustic-phonetic cues to find words in speech. Twelve-month-olds were familiarized to one passage containing an intended target (e.g., toga from toga#lore) and one passage containing an unintended target (e.g., dogma from dog#maligns). Infants were tested on the familiarized intended word (e.g., toga), familiarized unintended word (e.g., dogma), and two unfamiliar words. Infants listened longer to familiar intended words than to familiar unintended or unfamiliar words, demonstrating their use of word-level prosodically conditioned cues to segment words from speech. Implications for models of developmental speech perception are discussed.

Past research has indicated that English-learning infants begin segmenting words from speech by 7-5 months of age (Jusczyk & Aslin, 1995). More recent work has demonstrated, however, that 7-5-month-olds' segmentation abilities are severely limited. For example, the ability to segment vowel-initial words from speech reportedly does not appear until 13.5 to 16 months of age (Mattys & Jusczyk, 2001; Nazzi, Dilley, Jusczyk, Shattuck-Hufnagel & Jusczyk, 2005). In this paper, we report on three experiments using the Headturn Preference procedure that investigate both phonetic and phonological factors influencing 11-month-olds' segmentation of vowel-initial words from speech. We replicate earlier findings suggesting that infants have difficulty segmenting vowel-initial words from speech. In addition we extend these findings by demonstrating that under certain conditions, infants are capable of segmenting vowel-initial words from speech at a much younger age than earlier studies have reported. Our findings suggest that infants' ability to segment vowel-initial words from speech is tightly constrained by acoustic-phonetic factors such as pitch movement at the onset of vowel-initial words and segmental strengthening. These experiments underscore the complexity of early word segmentation, and highlight the importance of including contextual factors in developmental models of word segmentation.

The Possible Word Constraint limits the number of lexical candidates considered in speech recognition by stipulating that input should be parsed into a string of lexically viable chunks. For instance, an isolated single consonant is not a feasible word candidate. Any segmentation containing such a chunk is disfavored. Five experiments using the head-turn preference procedure investigated whether, like adults, 12-month-olds observe this constraint in word recognition. In Experiments 1 and 2, infants were familiarized with target words (e.g., rush), then tested on lists of nonsense items containing these words in "possible" (e.g., "niprush" [nip+rush]) or "impossible" positions (e.g., "prush" [p+rush]). The infants listened significantly longer to targets in "possible" versus "impossible" contexts when targets occurred at the end of nonsense items (rush in "prush"), but not when they occurred at the beginning (tan in "tance"). In Experiments 3 and 4, 12-month-olds were similarly familiarized with target words, but test items were real words in sentential contexts (win in "wind" versus "window"). The infants listened significantly longer to words in the "possible" condition regardless of target location. Experiment 5 with targets at the beginning of isolated real words (e.g., win in "wind") replicated Experiment 2 in showing no evidence of viability effects in beginning position. Taken together, the findings suggest that, in situations in which 12-month-olds are required to rely on their word segmentation abilities, they give evidence of observing lexical viability constraints in the way that they parse fluent speech.

The acquisition of variation is a fundamental – but poorly understood – part of child language acquisition. We fully endorse Shin and Miller's call for us to recognize the importance of this core issue, and argue that our understanding could be further enriched by greater reliance on convergent methods. As such, we implore researchers to consider perception as well as production data, and to consider acquisition across different domains and different populations of children. [ABSTRACT FROM AUTHOR]

Foreign accents can vary considerably in the degree to which they deviate from the listener's native accent, but little is known about how the relationship between a speaker's accent and a listener's native language phonology mediates adaptation. Using an artificial accent methodology, we addressed this issue by constructing a set of three artificial accents (Near, Far, and Farther), varying in the number and magnitude of pronunciation deviations from standard Canadian English. These accents were presented to toddlers and adults in an eye-tracking task. Regardless of accent type, adults readily adapted to the exposed pronunciation change. Adults exposed to the Farther accent were also more willing to accept novel pronunciation changes. Young toddlers exposed to Far or Farther accents showed no evidence of acquiring the exposed pronunciation change and demonstrated worse word recognition for standard Canadian-accented words. These findings suggest that when a speaker's accent deviates substantially from a young toddler's native accent, this may lead to a significant decrement in their ability to recognize not only an unfamiliar accent but also native-accented speech. Overall, these findings provide a well-controlled test of competing models of accent adaptation and generate multiple hypotheses to be examined in the future using more ecologically valid stimuli. [ABSTRACT FROM AUTHOR]

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 in intergenerational, adult-child dyads. In the current study, we investigated alignment between mothers and their children in a picture-naming task, as assessed using a perceptual similarity task and acoustic measures. Experiments 1 and 2 examined alignment in 2.5- and 4-year-old children and their mothers, both when mothers shadowed their children (Experiment 1), and when children shadowed their mothers (Experiment 2). Experiments 3 and 4 investigated long-term similarity between mothers and children when they were recorded separately. Results show that children and mothers aligned to one another in the shadowing task, regardless of who shadowed whom, and while there was no evidence for long-term alignment in younger children, there was some evidence of long-term alignment with 8-year-old children and their moms, but only for male children. [ABSTRACT FROM AUTHOR]

The infant literature suggests that humans enter the world with impressive built‐in talker processing abilities. For example, newborns prefer the sound of their mother's voice over the sound of another woman's voice, and well before their first birthday, infants tune in to language‐specific speech cues for distinguishing between unfamiliar talkers. The early childhood literature, however, suggests that preschoolers are unable to learn to identify the voices of two unfamiliar talkers unless these voices are highly distinct from one another, and that adult‐level talker recognition does not emerge until children near adolescence. How can we reconcile these apparently paradoxical messages conveyed by the infant and early childhood literatures? Here, we address this question by testing 16.5‐month‐old infants (N = 80) in three talker recognition experiments. Our results demonstrate that infants at this age have difficulty recognizing unfamiliar talkers, suggesting that talker recognition (associating voices with people) is mastered later in life than talker discrimination (telling voices apart). We conclude that methodological differences across the infant and early childhood literatures—rather than a true developmental discontinuity—account for the performance differences in talker processing between these two age groups. Related findings in other areas of developmental psychology are discussed. [ABSTRACT FROM AUTHOR]

Infants can make social judgments about characters by visually observing their interactions with others (e.g., Hamlin, Wynn & Bloom, Nature, 2007, 450, 557). Here, we ask whether infants can form similar judgments about potential social partners based solely on their tone of voice. In Experiment 1, we presented 10.5-month-olds with two visually neutral puppets. One puppet spoke in a positive affect and the other spoke in a negative affect. When the puppets were placed within reach of the infants, infants selected the formerly positive puppet. This preference disappeared when the voices were paired with nonsocial objects (Experiment 2). In Experiment 3, 10.5-month-olds were once again exposed to the same emotionally negative and positive voices. However, no visual characters were present. At test, infants’ visual orientation controlled how long they heard the neutral versions of each voice. Here, infants listened longer to the neutral voice of the formerly positive speaker. That is, just as in Experiment 1, infants’ preferences for the emotionally neutral test stimuli were shaped by their earlier exposure to emotionally charged recordings of that voice. Our findings provide convergent evidence to suggest that infants possess sophisticated social evaluation abilities, preferring to interact with prosocial over antisocial others. [ABSTRACT FROM AUTHOR]

Each clause and phrase boundary necessarily aligns with a word boundary. Thus, infants' attention to the edges of clauses and phrases may help them learn some of the language-specific cues defining word boundaries. Attention to prosodically well-formed clauses and phrases may also help infants begin to extract information important for learning the grammatical structure of their language. Despite the potentially important role that the perception of large prosodic units may play in early language acquisition, there has been little work investigating the extraction of these units from fluent speech by infants learning languages other than English. We report 2 experiments investigating Dutch learners' clause segmentation abilities. In these studies, Dutch-learning 6-month-olds readily extract clauses from speech. However, Dutch learners differ from English learners in that they seem to be more reliant on pauses to detect clause boundaries. Two closely related explanations for this finding are considered, both of which stem from the acoustic differences in clause boundary realizations in Dutch versus English. [ABSTRACT FROM AUTHOR]

Developmental sociolinguistics is a rapidly evolving interdisciplinary framework that builds upon theoretical and methodological contributions from multiple disciplines (i.e., sociolinguistics, language acquisition, the speech sciences, developmental psychology, and psycholinguistics). A core assumption of this framework is that language is by its very nature variable, and that much of this variability is informative, as it is (probabilistically) governed by a variety of factors—including linguistic context, social or cultural context, the relationship between speaker and addressee, a language user's geographic origin, and a language user's gender identity. It is becoming increasingly clear that consideration of these factors is absolutely essential to developing realistic and ecologically valid models of language development. Given the central importance of language in our social world, a more complete understanding of early social development will also require a deeper understanding of when and how language variation influences children's social inferences and behavior. As the cross‐pollination between formerly disparate fields continues, we anticipate a paradigm shift in the way many language researchers conceptualize the challenge of early acquisition. This article is categorized under:Linguistics > Linguistic TheoryLinguistics > Language AcquisitionNeuroscience > DevelopmentPsychology > Language [ABSTRACT FROM AUTHOR]

In speech addressed to adults, words are seldom realized in their canonical, or citation, form. For example, the word ‘green’ in the phrase ‘green beans’ can often be realized as ‘greem’ due to English place assimilation, where word-final coronals take on the place of articulation of neighboring velars. In such a situation, adult listeners readily ‘undo’ the assimilatory process and perceive the underlying intended lexical form of ‘greem’ (i.e. they access the lexical representation ‘green’). An interesting developmental question is how children, with their limited lexical knowledge, come to cope with phonologically conditioned connected speech processes such as place assimilation. Here, we begin to address this issue by examining the occurrence of place assimilation in the input to English-learning 18-month-olds. Perceptual and acoustic analyses of elicited speech, as well as analysis of a corpus of spontaneous speech, all converge on the finding that caregivers do not spoon-feed their children canonical tokens of words. Rather, infant-directed speech contains just as many non-canonical realizations of words in place assimilation contexts as adult-directed speech. Implications for models of developmental speech perception are discussed. [ABSTRACT FROM AUTHOR]