本研究旨在探討台灣高職生對英語子音之感受能力與發音能力之間的關係性。此外，本研究亦欲了解這些學生在此兩種能力上的精確度是否與子音在英文字中之位置有關。一共有的位來自北台灣某一所私立高級職業學校的學生參與本實驗。他們接受了一項針對兩個英語摩擦子音（即/s/及/θ/）所設計之聽力測驗及發音測驗。實驗所收集到的資料經由三個independent- samples t test統計測試分析，而其結果顯示：（1）這些學生對此兩子音之感受能力顯著陸地優於其發音能力；（2）當此兩子音出現在英文字字尾時，對這些學生們來說，比出現在字首時還更容易感受得出。但這種字尾優勢性並無延伸至其發音上之表現。因此，本研究發現，外語感受能力似乎發展於發音能力之前；而且在台灣這樣一個以英語為外語的情境中，對外語聲音在字首或字尾的感受難易度並不必然會對應於對外語聲音在字首或字尾之發音難易度。

This study primarily investigates whether Taiwanese vocational high EFL learners' perception precedes their production or otherwise their production precedes their perception by examining the relationship between the learners' perception and production of two English fricatives, /s/ and /θ/. Furthermore, the positions of the two fricatives in a word are scrutinized to discover if there is a significant difference between word-initial /s/ and /θ/ and word-final /s/ and /θ/ in perception and production. A total of 43 senior students from a private vocational high school in northern Taiwan were recruited to participate in this study. They were required to receive a listening identification test and a pronunciation test to measure their perception and production accuracy of the two consonants, /s/ and /θ/, in word-initial and word-final positions. The collected data were analyzed by three independent-samples t tests. The statistical results showed that the 43 participants' perception of the two consonants was significantly better than their production of the consonants. The results also revealed that when the two consonants occurred in word-final positions, they tended to be easier for the students to perceive; however, this word-final advantage did not extend to their production performance. The study suggested that FL perception precedes production and that in an EFL setting like Taiwan, the ease or difficulty in perceiving FL sounds in the word-initial or word-final position does not necessarily parallel the ease or difficulty in producing FL sounds in the word-initial or word-final position.