Rapid learning of minimally different words in five- to six-year-old children: effects of acoustic salience and hearing impairment

Word Learning in Deaf Adults Who Use Cochlear Implants: The Role of Talker Variability and Attention to the Mouth

OBJECTIVES

Although cochlear implants (CIs) facilitate spoken language acquisition, many CI listeners experience difficulty learning new words. Studies have shown that highly variable stimulus input and audiovisual cues improve speech perception in CI listeners. However, less is known whether these two factors improve perception in a word learning context. Furthermore, few studies have examined how CI listeners direct their gaze to efficiently capture visual information available on a talker's face. The purpose of this study was two-fold: (1) to examine whether talker variability could improve word learning in CI listeners and (2) to examine how CI listeners direct their gaze while viewing a talker speak.

DESIGN

Eighteen adults with CIs and 10 adults with normal hearing (NH) learned eight novel word-object pairs spoken by a single talker or six different talkers (multiple talkers). The word learning task comprised of nonsense words following the phonotactic rules of English. Learning was probed using a novel talker in a two-alternative forced-choice eye gaze task. Learners' eye movements to the mouth and the target object (accuracy) were tracked over time.

RESULTS

Both groups performed near ceiling during the test phase, regardless of whether they learned from the same talker or different talkers. However, compared to listeners with NH, CI listeners directed their gaze significantly more to the talker's mouth while learning the words.

CONCLUSIONS

Unlike NH listeners who can successfully learn words without focusing on the talker's mouth, CI listeners tended to direct their gaze to the talker's mouth, which may facilitate learning. This finding is consistent with the hypothesis that CI listeners use a visual processing strategy that efficiently captures redundant audiovisual speech cues available at the mouth. Due to ceiling effects, however, it is unclear whether talker variability facilitated word learning for adult CI listeners, an issue that should be addressed in future work using more difficult listening conditions.

Four-Year-Old's Online Versus Face-to-Face Word Learning via eBooks

Developmental research typically relies on face-to-face testing at laboratories, childcare centers, museums or playgroups. Current social distancing measures have led to a halt in research. Although face-to-face interaction is considered essential for research involving young children, current technology provides viable alternatives. This paper introduces an accessible, replicable and easy to follow method to conduct online developmental research with young children employing a word-learning task as an exemplar, including a detailed workflow and step-by-step guide to using easily accessible programs and platforms. Four-year-old children's (N = 56) performance on a word-learning task delivered online vs. face-to-face is provided as a method validation. Children's performance on the word-learning task was predominantly consistent across delivery modes, with only slight variation in performance between modes. The implications of these similar results across face-to-face and online methods are discussed alongside avenues for further research. Importantly, this paper presents an emerging methodological approach for the online administration of developmental science both within and beyond the COVID-19 pandemic, adding a new tool to current and future developmental scientist's toolkits.

Two-year-olds interpret novel phonological neighbors as familiar words

When children hear a novel word in a context presenting a novel object and a familiar one, they usually assume that the novel word refers to the novel object. In a series of experiments, we tested whether this behavior would be found when 2-year-olds interpreted novel words that differed phonologically from familiar words in only 1 sound, either a vowel or consonant. Under these conditions children almost always chose the familiar object, though examination of eye movements showed that children did detect the tested phonological distinctions. Thus, children discounted perceptible phonological variations when doing so permitted a resolution of the speaker's meaning without postulating a new word. Children with larger vocabularies made novel-word interpretations more often than children with smaller vocabularies did. The results suggest that although young children do interpret speech in terms of a learned phonological system, this does not mean that children assume that phonological distinctions imply lexical distinctions. (PsycINFO Database Record

Infants Encode Phonetic Detail during Cross-Situational Word Learning

Infants often hear new words in the context of more than one candidate referent. In cross-situational word learning (XSWL), word-object mappings are determined by tracking co-occurrences of words and candidate referents across multiple learning events. Research demonstrates that infants can learn words in XSWL paradigms, suggesting that it is a viable model of real-world word learning. However, these studies have all presented infants with words that have no or minimal phonological overlap (e.g., BLICKET and GAX). Words often contain some degree of phonological overlap, and it is unknown whether infants can simultaneously encode fine phonological detail while learning words via XSWL. We tested 12-, 15-, 17-, and 20-month-olds' XSWL of eight words that, when paired, formed non-minimal pairs (MPs; e.g., BON-DEET) or MPs (e.g., BON-TON, DEET-DIT). The results demonstrated that infants are able to learn word-object mappings and encode them with sufficient phonetic detail as to identify words in both non-minimal and MP contexts. Thus, this work suggests that infants are able to simultaneously discriminate phonetic differences between words and map words to referents in an implicit learning paradigm such as XSWL.