Students of Kanazawa Institute of Technology have been conducted “Experience on Sound propagation phenomena” for high school students as demonstration on campus visit day. To easily understand the phenomena, we have visualized a sound pressure distribution and then provided hands-on passive noise reduction experience. We prepared a glass tube with formed polystyrene balls and applied acoustic wave from the end. In the tube, the balls were arranged to distributions of sound pressure. Therefore, the high school students can observe standing wave in the tube. After the observation, our students have demonstrated various noise reduction experiments using polymer tubes with branched or bypassed structures. In the demonstration, the high school students felt an effect of the noise reduction structure not only using their own ear and finger for qualitative evaluation, but also using experimental apparatus for quantitative evaluation. In this paper, we describe the demonstrations and show the theory underlies the noise reduction experiment, and also discussed about an educational effectiveness of the hands-on experiments.