本文主要分析大肚方言漳腔及泉腔的方音差異及新興音變，我們調查53 位發音人，探究兩個研究問題：（一）臺中大肚方言漳腔及泉腔區的方音差異為何？（二）大肚漳腔及泉腔方言有哪些異於漳泉競爭的新興音變？大肚方言跟臺灣各地的漳、泉區相較起來，音變有同有異。不同的是臺灣多數方言點的調查顯示泉腔[dz]的衰退比漳腔快，然而大肚卻是漳腔區的[dz]比泉腔區更快衰退；相同處則是大肚泉腔區兩個央元音的崩潰是高央元音[ ]比中央元音[ə]更快消失，泉腔區的陽平變調也逐漸向漳腔的中平調靠攏。大肚方言有兩個跟漳泉變體競爭無關的新興音變，即/o/元音及陽入原調的變異與變化。泉腔區的/o/元音主要趨向展唇化成為[ə]，元音系統趨向/i, e, a, u, ə, /六元音演變；漳腔區/o/元音的變體以[ ]佔多數，因此元音系統主要趨向/i, e, a, u, /五元音，漳腔區也有部分/o/元音讀[ə]，亦即朝向/i, e, a, u, ə, /六元音。大肚方言陽入原調有共同的音變趨勢，不管漳腔或泉腔區，[-p]、[-t]、[-k]尾的陽入原調都有[33]逐漸被[32]取代的趨勢，喉塞尾的陽入調則以中平長調[33]佔多數。

This study analyzes the differences between Changchou and Chuanchou accents and new sound variations of the Taiwanese Hokkien in Tatu, also known as Dadu. We surveyed 53 informants to investigate two research questions: (1) What are the differences between Changchou and Chuanchou accents in Tatu? (2) What are the new sound changes of Changchou and Chuanchou accents in Tatu, which are not due to the competition between these two accents? For Changchou and Chuanchou accents, there are some common tendencies in sound change for both Tatu dialect and Taiwanese Hokkien. The results of this study showed that the high central vowel [ ] disappears earlier than the central vowel [ə]. In addition, the yangping tone sandhi of Chuanchou accent gradually develops into the mid-level tone. However, compared with most previous investigations revealing that sound [dz] declines faster in Chuanchou accents around Taiwan, this study found Changchou accents declines faster instead in Tatu dialect. We also probed two new sound changes of the vowel /o/ and the lower register entering tone in Tatu dialect. While the changes show no dominance to either accent, they are irrelevant to the competition of both accents. For example, the vowel /o/ found in Chuanchou accent mainly becomes [ə], a more spreading and unrounded vowel. The vowel system is mainly converted to the six vowels, /i, e, ə, a, u, /. In the other hand, the variants of the vowel /o/ in Changchou accent are mostly [ ], so that the system of five vowels /i, e, a, u, / dominates. Still, part of the vowel /o/ is pronounced as [ə], which constitutes a system of six vowels /i, e, ə, a, u, /. Secondly, the lower register entering tone has a common sound change in both Changchou and Chuanchou accents in Tatu dialects. Those tones ending with [-p]、[-t]、[-k] tend to change from [33] to [32], while the majority ones with a glottal stop remain mid-level tone [33].