Yue yu ying er dao xiang shi yu yan zhong sheng diao de yin gao bian hua: yu diao de ying xiang ji qi yu ying er yu yan fa zhan de guan xi

Ph.D.The main goal of this study is to provide new evidence regarding the debate over the primary function of infant-directed speech (IDS) by testing two hypotheses with lexical tones in IDS of Cantonese. The hyperarticulation hypothesis postulates that IDS serves a didactic linguistic function to facilitate infant language learning by making the contrasts between phonemes more salient. Alternatively, the prosodic hypothesis argues that IDS simply serves communicative functions through exaggerating prosody, and modifications of phonemes are unintended byproducts of prosodic modulation. Lexical tones offer a unique test case for identifying the primary function of IDS, as they are phonemically contrastive, yet its primary cue, pitch, is also a primary prosodic cue.In Experiment 1.1 (Chapter 2), the acoustic analyses of Cantonese IDS from 28 caregivers to their 15-month-old infants revealed an increase of intra-talker variation of lexical tones in IDS along with an expansion of tonal space, compared to adult-directed speech. The acoustic contrasts between lexical tones appeared not to be more salient in IDS, when considering both tonal space and tone variation.In Experiment 1.2 (Chapter 3), through correlation tests, strong positive relations were observed between lexical tone and intonational modifications in individual caregivers’ IDS, indicating that caregivers who exaggerated intonation more in IDS tended to produce lexical tones with both more expanded space and greater variation within categories. Multiple regression analyses further showed that the intonational factor but not the speech register significantly predicted both the tonal space and tone variation. The effects of the intonational factor on lexical tones were not modified by speech register, indicating no additional factor in IDS influencing the acoustic realization of lexical tones that cannot be accounted for by the intonational factor.In Experiment 2 (Chapter 4), both the tonal space expansion and the increase of tone variation were found to be present also in pet-directed speech (PDS). In PDS, intonation was exaggerated for communicative functions, but no hyperarticulation for a linguistic function was expected. Hence, the findings suggest that the lexical tone adjustments in IDS can be driven by intonational effects per se, regardless of whether there is any need for facilitating language learning.These new findings provide consistent evidence for the prosodic hypothesis. IDS may not provide more salient tone contrasts, and the lexical tone adjustments in IDS are very likely byproducts of intonational modifications. The support for the prosodic hypothesis by lexical tones further adds important evidence to the debate on the primary function of IDS. IDS may primarily serve a non-linguistic function.Additionally, the current study conducted an exploratory investigation into the influence of tone modifications in IDS on infant language development. In Experiment 3 (Chapter 5), the infants’ language outcomes were evaluated concurrently and later at 30-36 months old and correlated to the tone modifications in their caregivers’ IDS. No significant correlation was observed for the tonal space expansion, whereas negative correlations were found with respect to the increase of tone variation. Greater tone variation within categories in language input might pose challenges to infant language learning.本文主要目的是通過對粵語嬰兒導向式語言（兒向語）中聲調的研究來檢驗兩種假設，以此為兒向語主要功能的探討提供新的證據。語音誇張假設認為兒向語通過突出音位間的差別對比，發揮著語言教學功能，能夠促進嬰兒語言學習。另一韻律假設則認為兒向語只是通過誇張的韻律變化發揮交際溝通功能，而音位上的變化只是韻律調整的意外產物。聲調為研究兒向語主要功能提供了一個特殊案例，因為它既區別音位，又主要運用韻律線索音高作為區別性特徵。實驗一第一部份（第二章）對28 位看護人對其嬰兒（15 月齡）的粵語兒向語進行了語音分析。結果顯示與成人導向式語言相比，兒向語中除聲調整體空間的擴大外，每個看護人內部聲調的變化程度也有所上升。當同時將聲調空間和聲調變化程度納入考慮時，聲調間的差別對比在兒向語中並未得到突出。實驗一第二部份（第三章）中，通過相關性分析，我們發現各看護人兒向語中聲調與語調的變化顯示出較強的相關性，也就是說，兒向語的語調變化更為誇張的看護人往往也更多地擴大其聲調空間，同時其聲調內部變化程度也增加更多。多元回歸分析進一步顯示語調因素能夠顯著預測聲調空間大小及聲調變化程度而語域則不能。語調因素對聲調的作用不因語域的不同而改變，說明兒向語中應該不存在額外的無法被語調因素解釋的聲調影響因素。實驗二（第四章）中，聲調空間的擴大及聲調內變化程度的上升被發現同樣存在於寵物導向式語言中。寵物導向式語言中，語調發生著類似兒向語中的變化以發揮交際溝通功能，但一般認為不存在指向語言教學功能的語音誇張。因此，該實驗的發現說明兒向語中聲調的變化會受語調變化本身的影響而產生，無論是否存在語言教學的需要。本文的新發現一致為韻律假設提供了證據。兒向語中聲調間的差別對比並未得到突出，且聲調變化很可能是語調變化的產物。聲調研究對韻律假設的支持為有關兒向語主要功能的探討增添了重要證據。兒向語可能主要發揮著非語言教學的交際溝通功能。此外，本文還對兒向語中聲調變化對嬰兒語言發展的影響進行了探索性研究。實驗三（第五章）中，我們對嬰兒當時及一段時間後（30-36 月齡時）的語言發展進行了評估，並對所得結果與其看護人兒向語中聲調變化的關聯性進行了檢驗。對於兒向語中聲調空間的擴大，我們沒有發現任何顯著的相關性，但聲調內部變化程度的增加被發現與嬰兒語言發展結果呈現負相關。語言輸入中聲調內部較大的變化可能會為嬰兒語言學習帶來挑戰。Wang, Luchang.Thesis Ph.D. Chinese University of Hong Kong 2020.Includes bibliographical references (leaves 127-138).Abstracts also in Chinese.Title from PDF title page (viewed on January 19, 2022).Wang, Luchang