University of Al-Qadisiyah Al-Qadisiyah Journal for Engineering Sciences 1998-4456 6 2 2013 06 28 INVESTIGATION THE EFFECT OF THE REACTIVEMUFFLER CONNECTIONS ON NOISE ATTENUATION دراسة تأثير طرق الربط لكاتم الصوت التفاعلي على تخفيض الضوضاء 177 192 80753 EN Dr. Muna S. Kassim Journal Article 2013 06 01 A pollutant of concern to the mankind is the exhaust noise in the internal combustion engine. However this noise can be reduced sufficiently by means of a well designed muffler. The suitable design and development will help to reduce the noise level. The author design and fabricate a reactive muffler, spherical and cylinder shapes, afterward compared the noise level for these shapes with parallel and series connections. Transmission loss and transmission coefficient are calculated experimentally and theoretically for one, double and three mufflers in parallel and in series. Exhaust noise levels will aid the manufacturer in determining the correct muffler to meet the required noise reduction. These mufflers tested in frequency ranging between (50-600) Hz. In this study, the rustles show that the parallel connection is best than the series connection. https://qjes.qu.edu.iq/article_80753_88f8db49422bedbaeebe882c385fd0cc.pdf