This study examines the authenticity of overall speech speed of audio materials found in three Korean Listening textbooks. Based on the analysis and the comparison of the overall speech speed in the conversation of native Korean speakers and that of the audio materials, it was observed that the average speech speed of the audio materials is slower than that of authentic conversation. It was observed that this is due to the slower speed of pronouncing syllables in the conversations of the audio materials. It was also found that the proportion of pause is higher in the audio materials than in the authentic conversation, so that the speech speed is slower in the audio materials. The frequency of the pauses observed during the speech of a single speaker was higher than that of authentic conversations. Contrast to the different length of pauses found in authentic conversations, the length of pause in the audio materials turned out to be similar in most cases. This shows that speech speed and length of pause in numerous listening textbooks used in classrooms are not authentic. In order to add more authenticity to the listening materials, it is necessary to take such findings in practice. (Korea University)