兩歲遲語兒童的聲調知覺及其與詞彙學習的關係

Lexical-Tone Perception and Word Learning Abilities in Two-Year-Old Late-Talking Children

兩歲遲語兒的詞彙發展明顯落後同年齡幼兒。嬰幼兒的語音知覺能力是他們詞彙學習的基礎；而台灣目前普遍使用華語，其中「聲調」是華語的重要語音單位，具有標示音節詞彙意義的功能；因此「聲調知覺」能力在華語一般幼兒的詞彙發展上，扮演重要角色。本研究的主要目的在探索是否華語兩歲遲語兒在「聲調知覺」能力與一般幼兒有差異，以及聲調知覺能力與詞彙學習效能的關聯如何。本研究包含「遲語組」（n = 34）與配對性別、生理年齡、出生序及家中主要語言的「對照組」（n = 34）。研究作業包含華語嬰幼兒溝通發展量表、嬰幼兒發展測驗、測量聲調知覺能力的「聲調指認作業」（配對兩個單音節詞之聲調是最小對比）以及測量詞彙學習效能的「新詞學習作業」（指涉物選取與保留作業的形式）。結果發現遲語組的聲調知覺能力與詞彙學習效能皆較對照組差；相關分析的結果顯示遲語組的聲調知覺能力與詞彙學習效能有關，且逐步迴歸分析顯示，遲語組的聲調知覺能力對其詞彙學習效能的變異量有單獨之解釋量。本研究呈現華語兩歲遲語兒的聲調知覺能力落後配對幼兒，且他們的聲調知覺能力與詞彙學習效能有正向關聯。這些結果意涵，華語兩歲遲語兒較差的聲調知覺能力會干擾他們的詞彙學習效能。

The late-talking (LT) 2-year-old toddlers perform delayed vocabulary skills compared to their peers. Speech perception skills are essential to vocabulary development. For example, infants' speech perception abilities facilitate word learning, and speech perception in early infancy is predictive of later vocabulary development at 2-3 years of age. Lexical tones manifest the lexical meanings of syllables in Mandarin and are essential for typically-developing infants to learn words. Typically-developing 2-3 year-old children produce four lexical tones, but it is still an open issue regarding to the effects of lexical tone perception on word learning in Mandarin LT toddler. The goal of this study was to investigate whether the lexical-tone perception ability was associated with the word-learning performance in Mandarinspeaking LT toddlers. The participants were 2-year-old LT children (n = 34) and typically-developing children (TD, n = 34), matched with gender, chronological age, major language at home, and birth order. The lexical-tone perception ability was assessed with the forced-choice picture-pointing task, in which the child had to discriminate the lexical-tone minimal word pairs and map words with corresponding pictures. The word-learning efficiency was assessed with the referentselection and the word retention tasks. Results showed that the LT group performed poorer than the TD group in lexicaltone perception and word-learning efficiency. For the LT group, results of the correlation analyses showed that lexicaltone perception was correlated with word-learning efficiency. For the TD group, lexical-tone perception was correlated with vocabulary size and syntactic complexity. For the LT group, the stepwise regression analyses showed that the wordlearning efficiency could only be accounted for by lexical-tone perception. For the TD group, the results showed that the word-learning efficiency could be accounted for by vocabulary size and word using. The results demonstrate the poor lexical-tone perception ability in Taiwanese LT children. Moreover, the LT group's lexical-tone perception is associated with the word-learning efficiency, suggesting that the fragile lexical-tone representation could adversely affect the wordlearning efficiency in LT.