Listening comprehension has gained more prominence in EFL/ESL classes. Due to this prominence, scholars have tried to shed light on different ways of improving learners' listening comprehension. One of these ways is using listening strategies. There is still a controversy over the effective role of these strategies in improving listening comprehension. Thus, the proposed strategies have always been reviewed and reformed. Adopting either strategy, the course shall be quite ineffective if it fails to increase learners' participation in the course. The purpose of this study was to investigate whether or not peer-cooperative self-access materials adaptation has any effect on learners' involvement and participation in listening classes. In addition, the present study tried to probe any possible changes in students' attitude toward listening as a result of the treatment. In order to accomplish the purpose of the study, 90 Iranian students who were studying at Islamic Azad University, an independent university, were selected based on their obtained scores in a language proficiency test (TOEFL). They were randomly assigned to one control and two experimental groups. Then they undertook a 17-session treatment. With a quasi-experimental pretest posttest design, it became evident that having students adapt listening materials improved listening comprehension performance. And also a positive change occurred in students' overall attitude toward listening.