This study evaluates whether early vocalizations develop in similar ways in children across diverse cultural contexts. We analyze data from daylong audio-recordings of 49 children (1-36 months) from five different language/cultural backgrounds. Citizen scientists annotated these recordings to determine if child vocalizations contained canonical transitions or not (e.g., "ba" versus "ee").Results revealed that the proportion of clips reported to contain canonical transitions increased with age. Further, this proportion exceeded 0.15 by around 7 months, replicating and extending previous findings on canonical vocalization development but using data from the natural environments of a culturally and linguistically diverse sample. This work explores how crowdsourcing can be used to annotate corpora, helping establish developmental milestones relevant to multiple languages and cultures. Lower inter-annotator reliability on the crowdsourcing platform, relative to more traditional in-lab expert annotators, means that a larger number of unique annotators and/or annotations are required and that crowdsourcing may not be a suitable method for more fine-grained annotation decisions. Audio clips used for this project are compiled into a large-scale infant vocal corpus that is available for other researchers to use in future work.

This study evaluates whether babbling emerges similarly in children across diverse cultural contexts. We analyze data from daylong audio-recordings of 52 children (1-36 months) from six different language/cultural backgrounds. Citizen scientists annotated these recordings to determine if child vocalizations were canonical or not (e.g., "ba" versus "ee"). Results revealed that canonical babble increased with age. Further, a 0.15 canonical babble ratio emerged around 7 months, replicating and extending previous findings with data from the natural environments of a culturally and linguistically diverse sample. This work exemplifies how crowdsourcing can be used to annotate corpora, helping establish developmental milestones relevant to multiple languages and cultures. Audio clips used for this project are compiled into a large-scale infant babble corpus that is available for other researchers to use in future work.

Infants amass thousands of hours of experience with particular items, each of which is representative of a broader category that often shares perceptual features. Robust word comprehension requires generalizing known labels to new category members. While young infants have been found to look at common nouns when they are named aloud, the role of item familiarity has not been well-examined. This study compares 12-18-month-olds' word comprehension in the context of pairs of their own items (e.g. photos of their own shoe and ball) versus new tokens from the same category (e.g. a new shoe and ball). Our results replicate previous work showing that noun comprehension improves rapidly over the second year, while also suggesting that item familiarity appears to play a far smaller role in comprehension in this age-range. This in turn suggests that even before age two, ready generalization beyond particular experiences is an intrinsic component of lexical development.

Infants amass thousands of hours of experience with particular items, each of which is representative of a broader category that often shares perceptual features. Robust word comprehension requires generalizing known labels to new category members. While young infants have been found to look at common nouns when they are named aloud, the role of item familiarity has not been well-examined. This study compares 12-18-month-olds’ word comprehension in the context of pairs of their own items (e.g. photos of their own shoe and ball) versus new tokens from the same category (e.g. a new shoe and ball). Our results replicate previous work showing that noun comprehension improves rapidly over the second year, while also suggesting that item familiarity appears to play a far smaller role in comprehension in this age-range. This in turn suggests that even before age two, ready generalization beyond particular experiences is an intrinsic component of lexical development.

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