The present study was an attempt, to empirically investigate if there was any significant difference between authentic listening materials and their simplified version in terms of the listening comprehension of Iranian EFL learners. To this end, two groups of thirty subjects were chosen. One group received authentic listening materials and the other group received the same topic in simplified version through ten sessions. The subjects studied Top Notch Book, level 3. The listening parts were followed with seven listening comprehension questions to assess the listening comprehension of the subjects. Then, at the end of the course, the listening comprehension scores of the two groups were compared by a T-Test. The result showed that simplified demonstration of materials had a benefit over the use of authentic version. A questionnaire was also given to the subjects at the beginning and at the end of the course to find out their motivation toward using authentic or simplified materials. The result indicated that there was no significant difference between two groups in terms of motivation.