Learner journals or diaries have been used in various educational contexts to motivate learning and learner reflection. This study examines how learner journals, especially listening logs for extensive listening in a self-regulated environment, affected university students' listening proficiency, and how the students reported on their listening activities. Forty-two students who took an English listening practice course at a university kept a weekly listening log for a semester. They wrote their listening experience with various listening materials on different topics they chose. The TOEFL tests as pre-and post-tests were conducted to find out the effects of listening logs. A paired-samples test indicated there was a significant difference between the two tests. Analysis of listening logs showed that writing listening logs regularly influenced the students' improved listening comprehension and facilitated motivation. Also, students reflected on their listening strategies, and became accustomed to listening to a variety of listening resources. In addition, students often mentioned learning logs built confidence in their own listening and helped them to manage their learning. Finally, the study discusses the educational implications for listening logs and makes suggestions for future research.