This page covers the behavior of acoustic waves at interfaces and applications in guiding structures and resonators. It explains how vibrating surfaces generate acoustic waves, starting from point sou...This page covers the behavior of acoustic waves at interfaces and applications in guiding structures and resonators. It explains how vibrating surfaces generate acoustic waves, starting from point sources, and discusses the principle of reciprocity in linear acoustics, where acoustic antennas have proportional receiving and transmitting characteristics. Additionally, it briefly mentions electrodynamic-acoustic devices.