Research Database

Despite the importance of classroom language interactions for children’s school readiness skills and the school readiness gaps faced by Spanish-speaking emergent bilinguals (EBs), the field knows little about their classroom language interactions in early childhood education (ECE) classrooms. Expanding upon traditional approaches of observing classroom interactions, this study applies a child-centered analytic method to identify profiles of EBs classroom language interactions, characterized by their vocalizations and conversational turn-taking with teachers and peers, based on audio recordings. Data were drawn from 20 ECE classrooms and 171 EB children (ages 3 to 4) during the 2020–2021 school year. Latent profile analysis using variables from all-day recordings of EB children’s language environment identified three profiles: (1) limited classroom language interactions (58%); (2) engaging in conversations with teachers (14%); and (3) vocalizing and engaging conversations with peers (28%). EB children categorized to the second profile were less likely to speak Spanish and have teachers who spoke Spanish but were more likely to hear more words than EBs in profile 1. EBs children in profile 3 were likelier to be older than EBs in profile 1. Given that most EBs were in a profile of limited language interactions, the findings suggest the importance of improving opportunities and providing more support for EBs to engage in conversational turn-taking with their teachers and peers.

Infants are immersed in a world of sounds from the moment their auditory system becomes functional, and experience with the auditory world shapes how their brain processes sounds in their environment. Across cultures, speech and music are two dominant auditory signals in infants’ daily lives. Decades of research have repeatedly shown that both quantity and quality of speech input play critical roles in infant language development. Less is known about the music input infants receive in their environment. This study is the first to compare music input to speech input across infancy by analyzing a longitudinal dataset of daylong audio recordings collected in English-learning infants’ home environments, at 6, 10, 14, 18, and 24 months of age. Using a crowdsourcing approach, 643 naïve listeners annotated 12,000 short snippets (10 s) randomly sampled from the recordings using Zooniverse, an online citizen-science platform. Results show that infants overall receive significantly more speech input than music input and the gap widens as the infants get older. At every age point, infants were exposed to more music from an electronic device than an in-person source; this pattern was reversed for speech. The percentage of input intended for infants remained the same over time for music while that percentage significantly increased for speech. We propose possible explanations for the limited music input compared to speech input observed in the present (North American) dataset and discuss future directions. We also discuss the opportunities and caveats in using a crowdsourcing approach to analyze large audio datasets. A video abstract of this article can be viewed at https://youtu.be/lFj_sEaBMN4

Caregiver-child interactions are commonly used to examine children’s language learning environment. However, few studies consider interaction configurations beyond dyadic interactions or explore the conceptual complexity of caregiver talk. Thus, we examined if the complexity of a caregiver’s opportunities to respond (OTR) varied when sampled across three interaction configurations. Our study included twelve preschool-aged children with Down syndrome and both of their biological parents. Our preliminary findings suggest no differences in mothers’ and fathers’ frequency of OTRs across complexity levels during dyadic interactions. However, caregivers produced fewer OTRs across complexity levels during family choice than dyadic interactions.

We present an exploratory cross-linguistic analysis of the quantity of target-child-directed speech and adult-directed speech in North American English (US & Canadian), United Kingdom English, Argentinian Spanish, Tseltal (Tenejapa, Mayan), and Yélî Dnye (Rossel Island, Papuan), using annotations from 69 children aged 2–36 months. Using a novel methodological approach, our cross-linguistic and cross-cultural findings support prior work suggesting that target-child-directed speech quantities are stable across early development, while adult-directed speech decreases. A preponderance of speech from women was found to a similar degree across groups, with less target-child-directed speech from men and children in the North American samples than elsewhere. Consistently across groups, children also heard more adult-directed than target-child-directed speech. Finally, the numbers of talkers present in any given clip strongly impacted children’s moment-to-moment input quantities. These findings illustrate how the structure of home life impacts patterns of early language exposure across diverse developmental contexts.

There is little systematically collected quantitative empirical data on how much linguistic input children in small-scale societies encounter, with some estimates suggesting low levels of directed speech. We report on an ecologically-valid analysis of speech experienced over the course of a day by young children (N = 24, 6–58 months old, 33% female) in a forager-horticulturalist population of lowland Bolivia. A permissive definition of input (i.e., including overlapping, background, and non-linguistic vocalizations) leads to massive changes in terms of input quantity, including a quadrupling of the estimate for overall input compared to a restrictive definition (only near and clear speech), while who talked to and around a focal child is relatively stable across input definitions. We discuss implications of these results for theoretical and empirical research into language acquisition.

This study investigated language input (adult word count, AWC; conversational turn count, CTC; response types; high-, mid-, and low-level) and language outcomes (receptive, expressive) in children aged 2–5 years with hearing loss (CwHL) and those with normal hearing (CwNH). Associations between language input and outcomes, relationships between language input, and demographics were examined. Language input was analyzed using full-day Language Environment Analysis (LENA) audio-recordings, and language outcomes were assessed using standardized language assessments in 14 CwHL and 20 CwNH. There were no significant differences in language input between CwHL (AWC/hr: M = 1137, SD = 554; CTC/hr: M = 48.26, SD = 19.18) and CwNH (AWC/hr: M = 1243, SD = 426; CTC/hr: M = 60.94, SD = 21.34). There were, however, significant differences between groups in response types and language outcomes. Caregivers of CwHL used less high- and more mid- and low-level responses than caregivers of CwNH (p = < .01). Language input in CwHL showed no association with language outcomes, and there were no correlations with demographic factors. For CwNH, receptive language was correlated with AWC/hr, CTC/hr, and high- and low-level response types (p = < .01); and expressive language was correlated with AWC/hr (p = < .01), CTC/hr (p = .02), and high- (p = .02) and low-level (p = < .01) response types significantly. Correlations were negative for low-level response types, with lower language scores associated with relatively more use of low-level responses. For CwNH, maternal education correlated with AWC/hr (p = < .01), and caregivers of younger CwNH had significantly more CTC/hr (p = < .01). Quantitative LENA data suggested comparable interaction frequency between groups. CwHL were exposed to more low-level response types, had significantly lower language scores. Further investigation into response types, child language outcomes, and therapeutic implications for CwHL is needed.

Non-random exploration of infant speech-like vocalizations (e.g., squeals, growls, and vowel-like sounds or “vocants”) is pivotal in speech development. This type of vocal exploration, often noticed when infants produce particular vocal types in clusters, serves two crucial purposes: it establishes a foundation for speech because speech requires formation of new vocal categories, and it serves as a basis for vocal signaling of wellness and interaction with caregivers. Despite the significance of clustering, existing research has largely relied on subjective descriptions and anecdotal observations regarding early vocal category formation. In this study, we aim to address this gap by presenting the first large-scale empirical evidence of vocal category exploration and clustering throughout the first year of life. We observed infant vocalizations longitudinally using all-day home recordings from 130 typically developing infants across the entire first year of life. To identify clustering patterns, we conducted Fisher’s exact tests to compare the occurrence of squeals versus vocants, as well as growls versus vocants. We found that across the first year, infants demonstrated clear clustering patterns of squeals and growls, indicating that these categories were not randomly produced, but rather, it seemed, infants actively engaged in practice of these specific categories. The findings lend support to the concept of infants as manifesting active vocal exploration and category formation, a key foundation for vocal language.

Previous studies underscore the importance of social interactions for child language development— particularly interactions characterized by maternal sensitivity, infant-directed speech (IDS), and conversational turn-taking (CT) in one-on-one contexts. Although infants engage in such interactions from the third month after birth, the prospective link between speech input and maternal sensitivity in the first half year of life and later language development has been understudied. We hypothesized that social interactions embodying maternal sensitivity, IDS and CTs in the first 3 months of life, are significantly associated with later language development and tested this using a longitudinal design. Using a sample of 40 3-month-old infants, we assessed maternal sensitivity during a structured mother–infant one-on-one (1:1) interaction based on a well-validated scoring system (the Coding Interactive Behavior system). Language input (IDS, CT) was assessed during naturally occurring interactions at home using the Language ENvironment Analysis (LENA) system. Language outcome measures were obtained from 18 to 30 months of age using the MacArthur-Bates Communicative Development Inventory. Three novel findings emerged. First, maternal sensitivity at 3 months was significantly associated with infants’ productive language scores at 18, 21, 24, 27, and 30 months of age. Second, LENA-recorded IDS during mother–infant 1:1 interaction in the home environment at 3 months of age was positively correlated with productive language scores at 24, 27, and 30 months of age. Third, mother–infant CTs during 1:1 interaction was significantly associated with infants’ productive language scores at 27 and 30 months of age. We propose that infants’ social attention to speech during this early period—enhanced by sensitive maternal one-on-one interactions and IDS—are potent factors in advancing language development.

Recent advances in audiological early intervention and hearing technologies have significantly improved access to spoken language for children with hearing loss (CwHL), but many CwHL require additional support to match the language development of their peers with normal hearing (PwNH). Programmes such as It Takes Two to Talk®, the Hanen Program® and Talking Matters focus on supporting parents to enhance children’s language development in natural environments. Analysis of response types has become a significant trend, facilitated by technological developments like Language ENvironment Analysis (LENA®), which provides uninterrupted recordings and automated calculations of adult–child interactions. This research examined three child language measures, child vocalisation counts, total number of words, and mean length of utterance, comparing CwHL and PwNH. Transcribed excerpts of LENA recordings were coded to determine caregivers’ use of ‘high-level’ responses in exchanges with their children and were correlated with child language outcomes. The results confirm the crucial role of caregiver response types in enhancing child language outcomes and exemplify the bidirectional relationship of caregiver-child interactions. The findings add to the literature to suggest that families and educators would benefit from guidance and coaching to acquire and apply high-level response types during natural spoken language interactions with CwHL.

Background/Objectives: This study aimed to investigate whether day-long recordings with Language Environment Analysis (LENA) can be utilized in a hospital-based Auditory Verbal Therapy (AVT) program in Denmark for children with hearing loss and to conduct a pilot validation in the Danish language.

Introduction: Previous studies underscore the importance of speech input, particularly infant-directed speech (IDS) during one-on-one (1:1) parent–infant interaction, for child language development. We hypothesize that infants’ attention to speech input, specifically IDS, supports language acquisition. In infants, attention and orienting responses are associated with heart rate deceleration. We examined whether individual differences in infants’ heart rate measured during 1:1 mother–infant interaction is related to speech input and later language development scores in a longitudinal study.

A growing body of research suggests that young children’s early speech and language exposure is associated with later language development (including delays and diagnoses), school readiness, and academic performance. The last decade has seen increasing use of child-worn devices to collect long-form audio recordings by educators, economists, and developmental psychologists. The most commonly used system for analyzing this data is LENA, which was trained on North American English child-centered data and generates estimates of children’s speech-like vocalization counts, adult word counts, and child-adult turn counts. Recently, cheaper and open-source non-LENA alternatives with multilingual training have been proposed. Both kinds of systems have been employed in under-resourced, sometimes multilingual contexts, including Africa, where access to printed or digital linguistic resources may be limited. In this paper, we describe each kind of system (LENA, non-LENA), provide information on audio data collected with them that is available for reuse, review evidence of the accuracy of extant automated analyses, and note potential strengths and shortcomings of their use in African communities.

Researchers recommend collecting repeated or prolonged natural language samples to supplement direct assessments and anecdotal reports in language studies for autistic children. Several studies have used the Language Environment Analysis® (LENA) system to collect language samples from autistic children. However, there has been little research that investigates the reliability of using the LENA system for autistic children in an educational setting such as a classroom. The current study compared language data disaggregated by the LENA system from 40 autistic children in educational settings with data from human coders. Specifically, we calculated three separate correlational and reliability analyses between the LENA system and human coders. Results showed that although the aggregated coefficients could be interpreted as fair, LENA systems should be used with caution due to high variability between the LENA system and human coders. Implications for future research and limitations are also discussed.

Introduction: There is substantial diversity within and between contexts globally in caregiving practices and family composition, which may have implications for the early interaction’s infants engage in. We draw on data from the Brain Imaging for Global Health (BRIGHT, www.globalfnirs.org/the-bright-project) project, which longitudinally examined infants in the UK and in rural Gambia, West Africa. In The Gambia, households are commonly characterized by multigenerational, frequently polygamous family structures, which, in part, is reflected in the diversity of caregivers a child spends time with. In this paper, we aim to 1) evaluate and validate the Language Environment Analysis (LENA) for use in the Mandinka speaking families in The Gambia, 2) examine the nature (i.e., prevalence of turn taking) and amount (i.e., adult and child vocalizations) of conversation that infants are exposed to from 12 to 24 months of age and 3) investigate the link between caregiver diversity and child language outcomes, examining the mediating role of contingent turn taking.

Some theories of language development propose that children learn more effectively when exposed to speech that is directed to them (target child directed speech, tCDS) than when exposed to speech that is directed to others (other-directed speech, ODS). During naturalistic daylong recordings, it is useful to identify periods of tCDS and ODS, as well as periods when the child is awake and able to make use of that speech. To do so, researchers typically rely on the laborious work of human listeners who consider numerous features when making judgments. In this paper, we detail our efforts to automate these pro-cesses. We analyzed over 1,000 hours of audio from daylong recordings of 153 English- and Spanish-speaking families in the U.S. with 17- to 28-month-old children that had been previously coded by hu-man listeners for periods of sleep, tCDS, and ODS. We first explored patterns of features that character-ized periods of sleep, tCDS, and ODS. Then, we evaluated two classifiers that were trained using auto-mated measures generated from LENATM, including frequency (AWC, CTC, CVC) and duration (mean-ingful speech, distant speech, TV, noise, silence) measures. Results revealed high sensitivity and speci-ficity in our sleep classifier, and moderate sensitivity and specificity in our tCDS/ODS classifier. Moreo-ver, model-derived predictions replicated previously-published findings showing significant and posi-tive links between tCDS, but not ODS, and children’s later vocabularies (Weisleder & Fernald, 2013). This work offers promising tools for streamlining work with daylong recordings, facilitating research that aims to better understand how children learn from everyday speech environments.

Mothers and fathers modify prosodic characteristics of child-directed speech relative to adult-directed speech. Evidence suggests that mothers and fathers may differ in how they use child-directed speech as communicative partners. Thus, fathers create communicative challenges during father-child interaction that facilitate the child’s adaptation to a wider potential range of interlocutors. In this paper, speech production differences are examined between mothers and fathers in child-directed speech to toddlers as compared to adult-directed speech. Using a longitudinal, large-scale design of audio recordings in naturalistic environments and automatic speech processing techniques, it was found that mothers, but not fathers, increased their fundamental frequency when addressing their toddlers. The results suggest that fathers do not modulate the prosody of their speech in the same way as mothers when communicating with their toddlers. Findings have implications for emotional and communicative practices of fathers compared to mothers and the differential role each plays in child development.

This study focuses on parental use of parentese: the acoustically exaggerated, clear, and higher-pitched speech produced by adults across cultures when they address infants. While previous research shows that parentese enhances language learning and processing, it is still unclear what drives the variability in the amount of parental parentese use. We report on the development of a survey related to parental beliefs, knowledge, and self-awareness of parentese, and the cross-validation of this survey with daylong recordings in which parental parentese was measured through observation. Forty mother–father (18 monolingual English and 22 bilingual Spanish/English) U.S. families with infants between 3 and 24 months of age participated. Scores on the parentese questionnaire showed wide variability, suggesting that many parents were unsure about the effects of parentese on infant language development, and had limited self-awareness of their own parentese use. Almost half of the parents claimed that they talked to their child ‘like an adult’, and a similar number disagreed with the claim that parentese can support language learning. Our observational assessment of parentese demonstrated that all mothers and all fathers used parentese when talking to their infants; mothers in an average of 81% and fathers in an average of 69% of child-directed segments. Importantly, maternal parentese knowledge/beliefs scores, as well as their self-reported parentese use, were significantly positively correlated with observed parentese use; these relations were not significant for fathers. These results demonstrate that maternal and paternal links between beliefs, self-awareness, and behavior may be distinct, emphasizing the importance of studying all caregivers and using observational methodologies. More broadly, a thorough understanding of the factors that shape infants’ language environments contributes to theories of language acquisition and can aid in intervention design.

Language is a universal human ability, acquired readily by young children, who otherwise struggle with many basics of survival. And yet, language ability is variable across individuals. Naturalistic and experimental observations suggest that children’s linguistic skills vary with factors like socioeconomic status and children’s gender. But which factors really influence children’s day-to-day language use? Here, we leverage speech technology in a big-data approach to report on a unique cross-cultural and diverse data set: >2,500 d-long, child-centered audio-recordings of 1,001 2- to 48-mo-olds from 12 countries spanning six continents across urban, farmer-forager, and subsistence-farming contexts. As expected, age and language-relevant clinical risks and diagnoses predicted how much speech (and speech-like vocalization) children produced. Critically, so too did adult talk in children’s environments: Children who heard more talk from adults produced more speech. In contrast to previous conclusions based on more limited sampling methods and a different set of language proxies, socioeconomic status (operationalized as maternal education) was not significantly associated with children’s productions over the first 4 y of life, and neither were gender or multilingualism. These findings from large-scale naturalistic data advance our understanding of which factors are robust predictors of variability in the speech behaviors of young learners in a wide range of everyday contexts.

A wide variety of language skills has been shown to be compromised in children from low socioeconomic status (SES). However, few studies have investigated the effect of SES on language development in infants. The aim of this study is two-fold: to investigate when the first SES-effects on language can be observed and to explore the effects of three variables often claimed to be linked to SES – gestational duration, stress and parent-child interaction – on language development. Parents/caregivers of 539 Dutch-acquiring infants aged 8-13 months from mid to high SES backgrounds completed a questionnaire including the LENA Developmental Snapshot (Gilkerson et al., 2017a) and the Brigance Parent-Child Interaction Scale (Glascoe & Brigance, 2002). No association was found between SES and language development. However, the results suggest that corrected age and parent-child interaction positively influence language development at this early age.

The home language environment is a significant correlate of early childhood development outcomes; however, less is known about this mechanism in rural and peri-urban China where rates of developmental delay are as high as 52%. This study examines associations between the home language environment and child development in a sample of 158 children (58% boys) aged 18–24 months (Mage = 21.5) from rural and peri-urban households in Western China. Results show a significant association between adult-child conversation count and language development, suggesting the home language environment may be a mechanism for child development in rural and peri-urban China. 22.5% of the sample were at risk of language delay. Mother’s employment and child’s age were significant factors in the home language environment.