本研究旨在藉由測試台灣高職生對兩個英文母音(/i/ and /!/)之相對感受及發音困 難度以探討第二語言習得中對比分析假設之強硬版本在外語音段習得方面預測之精 確度。為了達到此目的，本研究之作者除了設計一套聽力與發音測驗來評估每位學 生對於該兩母音之感受及發音準確度之外，還提出兩項假設來驗證對比分析假設強 硬版本之預測：（1)倘若受試者在聽力及發音測驗上的表現/i/優於/!/，則證明該版本 在外語音段習得上之預測是精確的。（2)相反地，若測試的結果顯示學生在/!/聽力及 發音上的表現優於/i/，或兩個母音的表現不相上下，則證明該強硬版本之預測是錯 誤的。本研究一共網羅了39位來自北台灣一所私立高職的學生參與實驗。透過研究 者所設計之英文母音聽力及發音測試來了解受試者對受測母音之感受及發音能力。 俟所有測試成績收集完畢，研究者運用獨立樣本啦定來統計、分析相關資料。研究 結果顯示，受試者對於所受測之兩個母音之相對感受困難度為/i/ = /I/，而在相對發 音困難度上則為側/!/較為困難）。因此，本研究發現對比分析假設之強硬版本 所提出之預測僅發生在外語音段發音之習得上，而在感受習得上的預測並不成立。

This study primarily examined the predictions of the strong versiOn of the Contrastive Analysis Hypothesis (CAH) on Taiwanese vocational high school EFL students' acquisition of two English vowels (/if and /II) by investigating the learners' relative perceptual and productive difficulty of the vowels. To reach the goals, a listening identification test and a pronunciation test that were designed by the researchers were administered, and two research questions were formed. A total of 39 students from a private vocational high school in northern Taiwan were recruited to participate in this research. Their accuracy in perceiving and pronouncing the tested vowels was rated via the self-designed identification and production tests. After all the participants' test scores were collected, two independent-samples t-tests were conducted to analyze the data. The statistical results of the study showed that the relative perceptual difficulty of the two vowels for the students was /if = III but the relative productive difficulty for the learners was /J/ >Iii(> means more difficult than). The fmdings suggested that the predictions of the strong version of the CAH only worked for the participants' acquisition of the vowels in production.