閩南語元音演變路徑與觸發因素

本文從次方言比較角度，對比台南、新竹、廈門、鹿港、金門等五地，尋找閩南語單元音歸併演變路徑及其相關變化的可能觸發因素。台南與厦門（鼓浪嶼一帶）的發音相似，傳統閩南語的o、ɔ分立，都轉爲ə、o分立，顯示語言異地同變之追求系統均衡的普遍趨勢。若系統存在固有央元音ə、ɨ音位，傾向阻擋o前移，以免降低固有ə與o區別度，在泉州腔的金門與同安均可見此現象。鹿港老一輩可見到僅以舌位高低區別o、ɔ，但中青年層也普遍出現o元音前移趨勢；說明固有央元音ə阻擋o央化不是必然，次方言接觸強度會進一步誘發差異演變。語言優勢效應也影響了閩南語元音變化，當優勢華語進入生活各領域，促使閩南語中青年層元音系統朝向等同於華語的三個舌位高度發展；目前廈門、金門與台灣各地青年層閩南語元音都是三個舌位高度。總結而言，元音系統內部平衡機制、優勢語言影響、與次方言接觸強度等動力，綜合影響了當今閩南語元音系統歸併變化。

In this paper, the triggers and derivation trail of mid-vowel convergence in Southern Min is described by comparing the vowel systems of five Southern Min sub-dialects, those of Tainan, Hsinchu, Xiamen, Lugang, and Kinmen. The vowel systems of Tainan and Xiamen (around Gulangyu Island) are similar, in that the traditional contrast between /o/ and /ɔ/ is now a contrast of /ə/ and /o/, the changes involved being [o]-centralization and [ɔ]-raising. These identical phonological processes occurring in two separate Southern Min subdialects have resulted from a common background of subdialect mixture of Zhangzhou and Quanzhou, and from a general tendency towards vowel dispersion. On the other hand, in Kinmen and Tongan subdialects of Quanzhou, an intrinsic phonemic /ə/ in the vowel system seems to prevent an original /o/ from centralizing, since such a change would upset the phonemic distinction between /o/ and /ə/. In Lugang, another Quanzhou subdialect spoken in Changhua County, phonemic /o/ is distinct in height from /ɔ/ for the elder generation, but for the middle and younger generations there is a general tendency towards /o/-centralization. This suggests that /ə/ has not been able to completely block /o/-centralization, especially when the speech community is surrounded by /o/-centralizing subdialects. As Mandarin is now the dominant language for the youth of Xiamen, Kinmen, and Taiwan, their Southern Min vowel systems have been greatly influenced: from a traditional four-vowel-height distinction, they have assimilated to the three-vowel-height of Mandarin. In sum, various factors in combination have resulted in a convergence among Southern Min vowel systems, i.e. a language internal symmetric mechanism, dominant language influence, and the strength of sub-dialectal contact.