Exploration of the Phonetic Difference in Stops between Hakka Infant-Directed Speech and Adult-Directed Speech

客語成人語與兒向語的塞音語音差異探索

鄭明中(Ming-Chung Cheng)

《Concentric： Studies in Linguistics》 40卷1期 (2014/05) Pp. 1-35

https://doi.org/10.6241/concentric.ling.40.1.01

摘要

本研究旨在探討客語六個塞音［p, t, k, p^h, t^h, k^h］在成人語與兒向語中的語音表現差異是否對嬰兒的塞音習得有所助益。本研究的參與者包括五組母嬰配對。本研究所使用的成人語與兒向語語料，從嬰兒一個月大開始錄製，進行到嬰兒六個月大為止，每月錄音一次，為期半年。本研究所探討的塞音聲學參數包括濁音起始時間（VOT）、衝直條能量集中頻率區（以下簡稱強頻區）、以及輔音對音節長度比值（以下簡稱音節比），並採用PRAAT對語音進行切音與測量的工作。本研究結果如下：第一，不論塞音發音部位（雙唇、齒齦、軟顎）或後接元音（[i, a, u]）的差異，兒向語在送氣塞音的VOT上比成人語顯著來得長，但兩種語體在不送氣塞音的VOT上並沒有顯著的長短差異。兒向語裡送氣塞音與不送氣塞音的VOT差異擴大，有助於提升語音範疇化，促進語音可學性。第二，與成人語相比，兒向語裡不同發音部位的塞音（[p/p^h]，[t/t^h]，[k/k^h]）的強頻區都呈現顯著擴張，但是兩種語體中不同發音部位塞音都還是保持彼此之間在頻率上的顯著區別。整體而言，兒向語裡VOT及強頻區的變化維持著「變（化）中有（穩）定」，亦即兒向語中的語音擴張並不影響原先塞音在VOT及頻率上所呈現的語音分布格局。第三，就音節比而言，兒向語的比值均不大於成人語。這樣的結果，除了可以說明元音與輔音之間在發音上的本質差異之外，更可以顯示出維持適當的聲韻比例在語言習得中的重要角色。最後、本研究支持兒向語輔音研究中以感知為本的「語音提升」概念。總得來說，整體研究結果顯示，母親們系統性與技巧性地調整客語兒向語塞音的語音內容，這樣的調整無疑地有助於嬰兒對於塞音的習得。

關鍵字

兒向語 ； 成人語 ； 客家話 ； 塞音 ； 濁音起始時間

並列摘要

This study was concerned with phonetic realizations of six oral stops /p, t, k, p^h, t^h, k^h/ in Hakka collected from infant-directed speech (IDS) and adult-directed speech (ADS), and explored whether phonetic differences between them advantage infants’ language acquisition. Five mother-infant dyads took part in the recordings of ADS and IDS over the first six months after infants’ birth. Phonetic-acoustic correlates of oral stops were investigated, including voice onset time (VOT), spectral peak frequency of the release bursts, and obstruent/syllable (O/S) ratio. The results of this research were listed as follows. First, regarding VOT, IDS had longer VOT than ADS in aspirated stops, but not in nonaspirated stops, no matter which factor (i.e. place of articulation of stops or following vowel context [i, a, u]) was taken into consideration. The expanded VOT difference between aspirated and nonaspirated categories in IDS might benefit infants’ phonetic categorization and facilitate language learnability. Next, compared with ADS, spectral peak frequencies of stops produced in different places of articulation (PoAs) were significantly heightened in IDS, but stops with different PoAs remained spectrally separable from one another. Third, the O/S ratios in IDS were not larger than those in ADS, illustrating not only the articulatory difference between vowel and consonant in lengthening but also the role of proper onset-rime percentages in syllables for language acquisition. Finally, this study supported the concept of perceptually-based ＂phonetic enhancement＂ in IDS consonantal studies. To be conclusive, mothers modified Hakka stops addressed to infants systematically and strategically, and provided well-specified VOT distinctions among different stops.

並列關鍵字

infant-directed speech ； adult-directed speech ； Hakka ； stops,voice onset time

參考文獻

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