台灣閩南語產製與感知中發聲起始時間與基本頻率的效果

The effect of VOT and F0 in the production and perception in Taiwanese Southern Min

谷口詩織(Shiori Taniguchi)

指導教授 ： 邱振豪

國立臺灣大學/文學院/語言學研究所/碩士(2021年)

https://doi.org/10.6342/NTU202101176

摘要

本研究的目的是調查嗓音起始時間 (Voice Onset Time; VOT) 和 基頻 (F0) 對台灣南部閩南語產製和感知的影響。過去的研究發現，塞音的 VOT 長短會影響後續母音的 F0。這種效果通常被稱為「跳音效果」。本研究針對在跳音效果相關的文獻中兩個未解決/未被注意的問題進行探討。第一個研究議題是關於聲調語言跳音效果的時間範圍（即，後續母音中的F0有多少部分是受前面的塞音的嗓音特質的影響）。部分研究報告指出，跳音效果僅持續很短的時間（約20 到 30 毫秒），而其他研究則報告了更長的持續時間（超過 100 毫秒）。本研究假設跳音效果的時間範圍是由音高目標的數量決定；在具有大量音高目標的語言中，跳音效果下降得更早，以保持音高目標之間的音素區別。為了檢驗這個假設，本研究調查了台灣閩南語不同嗓音特質其聲調曲線的相對比例。實驗要求二十名台灣閩南語母語者產製「清送氣」、「清不送氣」和「濁音」三類發聲對比的塞音音節首。結果顯示，接續在「清送氣」音後的F0最高，「清不送氣」次之，「濁音」最低。值得注意的是，這種跳音效果並沒有持續超過母音長度的 25%，這些結果表明在像台灣閩南這樣具有大量音高目標的語言中，跳音效果持續時間明顯較短。
第二個研究議題則是試圖了解在三類發聲對比的語言中，跳音效果如何影響受試者的感知判斷。先前泰語的研究指出，塞音除阻後的 F0 變化會影響濁、清音的聲判斷，但不影響送氣與否判斷。但F0 變化不影響送氣與否的判斷究竟是泰語特有的，還是也存在於其他具有類似三類發聲對比的其他語言中，依舊懸而未決。為了回答這個問題，另外二十名台灣閩南語母語者參加了VOT和F0的感知實驗。刺激材料調整了不同的VOT與F0組合，試圖檢視塞音除阻後的F0變化對判斷清濁音與送氣與否的影響。結果顯示，F0 變化會影響濁音與清音和送氣音與不送氣音的感知判斷。
綜上所述，本研究有助於我們理解塞音的嗓音起始如何影響聲調語言中後續母音的 F0。就時間範圍而言，台灣閩南語的跳音效果結束地較早。同時，感知實驗的結果也顯示了 F0 可以作為清濁和送氣對比的感知線索。這些發現也更進一步強化了F0在產製和感知中的角色以及彼此之間的聯繫。

關鍵字

跳音效果 ； 發聲判斷 ； 音高目標的數量 ； 三類發聲對比 ； 台灣閩南語

並列摘要

The purpose of this study is to investigate the effect of VOT (voicing quality of the consonant) and F0 of stops in the production and perception in Taiwanese Southern Min. The VOT of a stop is known to affect the F0 of the following vowel. This effect is often termed the ‘pitch skip effect.’ This study addresses two unanswered/unattended issues in the literature on the pitch skip effect. The first one is on the temporal extent of the pitch skip effect (i.e., how much of the F0 into the following vowel is influenced by the voicing quality of the preceding stop) in tone languages. Some studies report that the pitch skip effect lasts only for a short period of time (~20 to 30 ms) while some other studies report the longer durations (over 100 ms). This study hypothesizes that the temporal extent of the pitch skip effect is determined by the number of pitch targets; the pitch skip effect declines earlier (the proportion influenced by the effect is smaller) in languages with a large number of pitch targets to retain the distinction between the pitch targets. To test this hypothesis, the relative proportion of the influenced pitch contour in Taiwanese Southern Min was investigated. Twenty native speakers of Taiwanese Southern Min produced stop onsets with three-way contrasts across voiceless aspirated, voiceless unaspirated and voiced. The results show that the F0 after voiceless aspirated stops is the highest, followed by that after voiceless unaspirated stops and then voiced stops. Notably, this pitch skip effect ends before 25% into the vowel, suggesting an early decline of the pitch skip effect in languages with a large number of pitch targets like Taiwanese Southern Min.
The second one tackles the pitch skip effect on the perception in languages with three-way voicing contrasts. A previous research on Thai reports that the post-stop-release F0 change affects the voicing judgment in voiced-voiceless identification task but not in aspirated-unaspirated identification task. It remains unexplained whether the fact that the F0 change is not used for the perception of the aspirated-unaspirated contrast is specific to Thai or also present in other languages with similar three-way voicing contrasts. To answer this question, another twenty native speakers of Taiwanese Southern Min judged the voicing of continua varying by VOT and F0, and the effect of post-stop-release F0 change on voicing judgment was investigated. The results show that the F0 change affects the perception of voicing contrasts in both voiced-voiceless and aspirated-unaspirated identifications. This suggests that the F0 change may be associated with the perceptual contrasts in both voiced-voiceless and aspirated-unaspirated identifications in Taiwanese Southern Min.
Taken together, this study contributes to our understanding of how the voicing contrast of stops affects the F0 of the following vowel in tone languages. In terms of the temporal extent, the current study also reveals that the pitch skip effect declines earlier in Taiwanese Southern Min. Through the results of the perception experiment, it is also suggested that F0 may serve as a perceptual cue to the voicing and aspiration contrasts, which further strengthens the view of a strong F0 effect in both production and perception and the connection between them.

並列關鍵字

pitch skip effect ； voicing judgment ； number of pitch targets ； three-way voicing contrast ； Taiwanese Southern Min

參考文獻

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