This study investigates the voice onset time (VOT) of L2 English stops produced by native speakers of Chinese at different L2 proficiency levels. Four factors were examined: English proficiency, gender, place of articulation, and vowel context. High and low achievers of English were recruited as the experimental groups and native speakers of English as the control group. Each group consisted of 16 participants, 8 males and 8 females. Each participant took part in a read-aloud task, in which the target words were presented in an embedded sentence.

The results showed that the effects of L2 proficiency were significant in that high achievers outperformed low achievers who were affected by L1 negative transfer more seriously when producing native-like English stops. Additionally, when producing English stops, velar stops had significantly greater VOT values than either bilabial or alveolar ones. However, no significant gender differences were found. Male and female participants produced similar VOT values in English stops. Last, the vowel context was also a significant factor. The VOT lengths differed according to the context of a following vowels. More specifically, the VOT of a stop is significantly longer when followed by a tense vowel.

本研究調查有著不同英語(L2)程度的中文母語人士產生的英語塞音嗓音起始時間（VOT）。研究考察了四個因素：英語程度、性別、發音位置和元音特性。高成就和低成就的英語學習者被招募為實驗組，而英語母語者則為對照組。每個組別包括 16 名參與者，男女各 8 人。每位參與者參加了一項朗讀任務，其中目標詞語被呈現在一個句子中。

結果表明，英語(L2)程度的影響是顯著的，英語程度較高者在產生與母語相似的英語塞音時表現優於英語程度較低者，因為後者受到 L1 負面轉移較為嚴重。此外，在產生英語塞音時，軟顎塞音的 VOT 值顯著地大於雙唇塞音或齒龈塞音。然而，本研究並沒有發現顯著的性別差異:男性和女性參與者在產生英語塞音時產生的 VOT 值相似。最後，元音特性也是一個重要因素。根據後接元音的環境，VOT 值的長度有所不同。具體而言，當後接一個緊元音時，塞音的 VOT 值顯著地更長。