Sound Transmission Loss of Panels with Resonant Elements

Various types of resonant elements that can be used for increasing the transmission loss of panels in narrow frequency bands are analyzed. The main physical phenomena determining the transmission loss of sound waves in panels with resonant elements are studied. Three main principles of increasing the transmission loss realized in panels with resonant elements are described: the principle of soft reflection, the principle of hard reflection, and the principle of compensation. The relations for estimating the transmission loss of panels with resonant elements, which model the main physical phenomena governing the propagation of sound waves, are presented.