This study investigated the multidimensional effects of extensive listening (EL) on learners’ language gains, selection of study materials, practice styles, and their perceived effectiveness of EL. Fifty-five university students took part in a four-month EL experiment. Each week students kept a listening log recording what materials they selected, how they practiced, and how much time they practiced. Students also reported the content they practiced to their instructor at the weekly meeting. Language gains were measured through a pre-test and a post-test on students’ aural vocabulary test (Listening Vocabulary Levels Test, LVLT) and general listening comprehension (TOEIC). The perceived effectiveness of EL was collected through a 32-item questionnaire. Overall, students made significant improvements on their aural vocabulary knowledge and listening comprehension, which were consistent with their perceived effectiveness of EL. The questionnaire results revealed that most students liked and were able to select their study materials that suited their language levels and interests. In addition, EL was found to be a very individual activity because many students were reluctant to share or discuss with their friends about what they had practiced. Their practice style was mainly a combination listening plus viewing. Some issues encountered in the implementation of EL were discussed and suggestions were made.