Influences of vowel and tone variation on emergent word knowledge: a cross‐linguistic investigation

Abstract

To learn words, infants must be sensitive to native phonological contrast. While lexical tone predominates as a source of phonemic contrast in human languages, there has been little investigation of the influences of lexical tone on word learning. The present study investigates infants' sensitivity to tone mispronunciations in two groups of infants. For one group (Chinese learners), tone is phonemic in their native language, and for the second group (English learners), tone is non-phonemic and constituted suprasegmental variation. In Experiment 1, English learners were trained on novel word-object pairings and tested on their recognition of correct pronunciations, tone and vowel mispronunciations of these words at 18 and 24 months. In Experiment 2a, bilingual English-Chinese learners were tested on a similar task translated into Chinese at the same age intervals. Results demonstrate that non-tonal learners treated tonal and vowel substitutions alike as mispronunciations at 18 months but only treated vowel substitutions as mispronunciations at 24 months. Tonal learners treated both tonal and vowel substitutions as mispronunciations at both ages. In Experiment 2b, bilingual non-tone language learners were tested on the same set of tasks replicating a similar set of results as monolingual non-tone language learners (Experiment 1). Findings point to an early predisposition to treat tone as a defining characteristic of words regardless of its lexical relevance at 18 months. Between 18 and 24 months, learners appear to ascribe lexical relevance to tone in a language-specific manner. The current study identifies the influences of tone variation on memories for newly learned words and the time period during which lexical tone - a highly frequent constituent of human languages - actually becomes lexical for early learners. Findings are contextualized with prevailing models of the developing lexicon.

Tone Attrition in Mandarin Speakers of Varying English Proficiency

“…Tone-language learners' tone discrimination is maintained within the first year of life, whereas intonation-language learners' tone discrimination worsens (Mattock & Burnham, 2006;Mattock, Molnar, Polka, & Burnham, 2008;Yeung, Chen, & Werker, 2013; see also Harrison, 2000). At the lexical level, language-specific pitch processing seems to develop by about 11 months for recognition of word forms (Singh & Foong, 2012) and by about 17 months for word learning (Hay, Graf Estes, Wang, & Saffran, 2014;Quam & Swingley, 2010;Singh, Hui, Chan, & Golinkoff, 2014).…”

The Distribution of Talker Variability Impacts Infants’ Word Learning

“…They are willing to treat pitch contour as lexically contrastive (Singh et al, 2014;Frota et al, 2012;Hay et al, 2015; see also Quam & Swingley, 2010). Until roughly 20 months of age, children are generally more willing than older learners to accept even non-word-like symbols, such as gestures, noise-maker sounds, and pictograms, as potential words (Namy, 2001;Namy & Waxman, 1998;Woodward & Hoyne, 1999).…”

“…At the same time, younger infants are more willing than older learners to attend to acoustic dimensions that are not contrastive in their language. For instance, before about 17 months, English-learning infants are willing to learn and differentiate words based on their pitch patterns (Singh et al, 2014;Hay et al, 2015; see also Quam & Swingley, 2010). Thus, even after the early "perceptual reorganization" for native-language sound discrimination, infants are still learning to attend to contrastive dimensions and listen through noncontrastive dimensions in word learning.…”

Spoken word recognition in early childhood: Comparative effects of vowel, consonant and lexical tone variation

“…In auditory word segmentation, tone language learning infants appear to integrate tones into wordforms in a language-specific manner by 11 months (Singh & Foong, 2012). Later, by 18 months, toddlers learning a tone language integrate lexical tones into newly learned words (Singh, Tam, Chan, & Golinkoff, 2014). Finally, studies with preschool and school-aged children demonstrate that native tone language learners can discriminate familiar words based on lexical tone with a high level of accuracy in auditory discrimination experiments (Burnham et al, 2011;Ciocca & Lui, 2003;Wong, Ciocca, & Yung, 2009).…”

“…Previous studies investigating novel word learning have revealed that tone is recognized to be phonemic in toddlers: language-specific integration of lexical tone into word learning is evident at 2 years of age (Singh et al, 2014). As such, responses to mispronunciation effects were studied within a sample of toddlers (2.5-3.5 years), when vowels, consonants and tones are likely to be recognized as lexically relevant and substitutions in any of these phonemes treated as a mispronunciation.…”