Publications

Abstract

Language is a universal human ability, acquired readily by young children, whootherwise struggle with many basics of survival. And yet, language ability is variableacross individuals. Naturalistic and experimental observations suggest that children’slinguistic skills vary with factors like socioeconomic status and children’s gender.But which factors really influence children’s day-to-day language use? Here, weleverage speech technology in a big-data approach to report on a unique cross-culturaland diverse data set: >2,500 d-long, child-centered audio-recordings of 1,001 2- to48-mo-olds from 12 countries spanning six continents across urban, farmer-forager,and subsistence-farming contexts. As expected, age and language-relevant clinical risksand diagnoses predicted how much speech (and speech-like vocalization) childrenproduced. Critically, so too did adult talk in children’s environments: Children whoheard more talk from adults produced more speech. In contrast to previous conclusionsbased on more limited sampling methods and a different set of language proxies,socioeconomic status (operationalized as maternal education) was not significantlyassociated with children’s productions over the first 4 y of life, and neither weregender or multilingualism. These findings from large-scale naturalistic data advanceour understanding of which factors are robust predictors of variability in the speechbehaviors of young learners in a wide range of everyday contexts

Abstract

Rapid response latencies in conversation suggest that responders start planning before the ongoing turn is finished. Indeed, an earlier EEG study suggests that listeners start planning their responses to questions as soon as they can (Bögels, S., Magyari, L., & Levinson, S. C. (2015). Neural signatures of response planning occur midway through an incoming question in conversation. Scientific Reports, 5, 12881). The present study aimed to (1) replicate this early planning effect and (2) investigate whether such early response planning incurs a cost on participants’ concurrent comprehension of the ongoing turn. During the experiment participants answered questions from a confederate partner. To address aim (1), the questions were designed such that response planning could start either early or late in the turn. Our results largely replicate Bögels et al. (2015) showing a large positive ERP effect and an oscillatory alpha/beta reduction right after participants could have first started planning their verbal response, again suggesting an early start of response planning. To address aim (2), the confederate's questions also contained either an expected word or an unexpected one to elicit a differential N400 effect, either before or after the start of response planning. We hypothesized an attenuated N400 effect after response planning had started. In contrast, the N400 effects before and after planning did not differ. There was, however, a positive correlation between participants' response time and their N400 effect size after planning had started; quick responders showed a smaller N400 effect, suggesting reduced attention to comprehension and possibly reduced anticipatory processing. We conclude that early response planning can indeed impact comprehension processing.

Abstract

Speaker diarization (answering 'who spoke when') is a widely researched subject within speech technology. Numerous experiments have been run on datasets built from broadcast news, meeting data, and call centers—the task sometimes appears close to being solved. Much less work has begun to tackle the hardest diarization task of all: spontaneous conversations in real-world settings. Such diarization would be particularly useful for studies of language acquisition, where researchers investigate the speech children produce and hear in their daily lives. In this paper, we study audio gathered with a recorder worn by small children as they went about their normal days. As a result, each child was exposed to different acoustic environments with a multitude of background noises and a varying number of adults and peers. The inconsistency of speech and noise within and across samples poses a challenging task for speaker diarization systems, which we tackled via retraining and data augmentation techniques. We further studied sources of structured variation across raw audio files, including the impact of speaker type distribution, proportion of speech from children, and child age on diarization performance. We discuss the extent to which these findings might generalize to other samples of speech in the wild.

Abstract

Word count estimation (WCE) from audio recordings has a number of applications, including quantifying the amount of speech that language-learning infants hear in their natural environments, as captured by daylong recordings made with devices worn by infants. To be applicable in a wide range of scenarios and also low-resource domains, WCE tools should be extremely robust against varying signal conditions and require minimal access to labeled training data in the target domain. For this purpose, earlier work has used automatic syllabification of speech, followed by a least-squares-mapping of syllables to word counts. This paper compares a number of previously proposed syllabifiers in the WCE task, including a supervised bi-directional long short-term memory (BLSTM) network that is trained on a language for which high quality syllable annotations are available (a “high resource language”), and reports how the alternative methods compare on different languages and signal conditions. We also explore additive noise and varying-channel data augmentation strategies for BLSTM training, and show how they improve performance in both matching and mismatching languages. Intriguingly, we also find that even though the BLSTM works on languages beyond its training data, the unsupervised algorithms can still outperform it in challenging signal conditions on novel languages.

Abstract

Understanding how communicative goals impact and drive the learning process has been a long-standing issue in the field of language acquisition. Recent years have seen renewed interest in the social and pragmatic aspects of language learning: the way interaction shapes what and how children learn. In this volume, we bring together researchers working on interaction in different domains to present a cohesive overview of ongoing interactional research. The studies address the diversity of the environments children learn in; the role of para-linguistic information; the pragmatic forces driving language learning; and the way communicative pressures impact language use and change. Using observational, empirical and computational findings, this volume highlights the effect of interpersonal communication on what children hear and what they learn. This anthology is inspired by and dedicated to Prof. Eve V. Clark – a pioneer in all matters related to language acquisition – and a major force in establishing interaction and communication as crucial aspects of language learning.

Abstract

A key part of learning to speak with others is figuring out when to start talking and how to hold the floor in conversation. For young children, the challenge of planning a linguistic response can slow down their response latencies, making misunderstanding, repair, and loss of the floor more likely. Like adults, children can mitigate their delays by using fillers (e.g., uh and um) at the start of their turns. In this chapter I analyze the onset and development of fillers in five children’s spontaneous speech from ages 1;6–3;6. My findings suggest that children start using fillers by 2;0, and use them to effectively mitigate delay in making a response.

Abstract

Conversation is a structured, joint action for which children need to learn a specialized set skills and conventions. Because conversation is a primary source of linguistic input, we can better grasp how children become active agents in their own linguistic development by studying their acquisition of conversational skills. In this chapter I review research on children’s turn-taking. This fundamental skill of human interaction allows children to gain feedback, make clarifications, and test hypotheses at every stage of development. I broadly review children’s conversational experiences, the types of turn-based contingency they must acquire, how they ask and answer questions, and when they manage to make timely responses