This study investigated the effects of incorporating e-books into instructional material on reading and listening development among secondary school students with different levels of English proficiency. The experimental group utilized an e-book in regular English class, and the control group used a print version with the same content. An achievement test and focus-group interview followed the six-week e-book intervention. The test results showed that the e-book had a positive impact on listening comprehension, particularly for low-proficiency students. For these students, multimedia input combined with a standard accent seemed more effective for the development of listening skills than access to only the foreign-accented English spoken by the teacher. Furthermore, the use of visual aids, such as images and captions, might support listening comprehension by helping the students visualize auditory input and providing contextual information. Audio-only input might not be enough for low-proficiency students, who have relatively limited capability to recognize words from speech. With regard to reading, the e-book intervention resulted in higher test scores compared to the print book, but the between-group difference did not reach statistical significance. Possible reasons include a small sample size in each proficiency group as well as technical restrictions and distraction caused by multimedia material. The interview data indicates that the use of technology was not perceived as particularly beneficial for learning. Instead, diverse classroom activities and interactions were considered more important than the technology itself to draw students' attention and sustain their motivation. Pedagogical implications of the results are discussed.