Noise reduction through periodic serial side branches containing two defects

Noise pollution is a challenging issue requiring the development of acoustic systems that can reduce noise. Besides environmental impacts noise pollution, it cause serious health problems. This work originally discusses reduction using new configuration side branches grafted in series with different terminations. The combination two serial resonators shows coupling effects. effect used to increase localized modes defective located middle structure. transmission waves be controlled by dimensions introduced defects as well their boundary conditions. We also show totally filter pass-bands. proposed structure then play role an acoustical filter.