The present study attempted to investigate the effects of audio input enhancement on EFL learners' retention of intensifiers. To this end, two research questions were formulated. In order to address these research questions, this study attempted to reject two null hypotheses. Pretest-posttest control group quasi-experimental design was employed to determine the extent to which audio input enhancement could have an effect on the retention of intensifiers by EFL learners. Cluster sampling was used and 43 students participated in the study. They were assigned into two groups: an audio input enhancement group and a control group. A multiple choice test of English intensifiers was used during three phases of the study to collect the required data. The reliability of the test was estimated to be 0.74. At the initial stage, English-Beginner Test was administered to assure the students' homogeneity. Before implementing the treatment, a pre-test consisting of 20 multiple-choice items on intensifiers was administered to ensure that the participants' knowledge of the target forms was more or less the same. English intensifiers were taught through audio input enhancement in the experimental group; however, no input enhancement was applied in the control group.