An investigation into the effectiveness of multi-faceted lexical instruction is also important because an insufficient knowledge of vocabulary appears to be a leading cause of stress among EFL listeners. Boyle (1984) determined, based upon the opinions of 60 students in Hong Kong, that they considered vocabulary the most important aid to the effectiveness of listening comprehension. Kelly’s (1991) later investigation scrutinized errors made by EFL learners in transcription and translation after listening to extracts recorded from the BBC. Between lexical, perceptional, and syntactical errors, lexical ignorance was again regarded to be the primary obstacle for these students. Taiwanese EFL learners experience the same difficulties as other EFL learners. Chao and Cheng (2004) investigated the listening difficulties of students from four senior high schools, and students in that study felt that their lack of a sufficient vocabulary led to listening difficulties. Along the same lines, Chien and Kao (2002) found that students believed an increased L2 vocabulary would improve listening comprehension. Since the limited vocabulary possessed by students presents obstacles to their successful comprehension of spoken English, we should assess the effectiveness of lexical intervention on their listening performance.