Аннотация:The universal theory of “parametric” sound emitters is presented, taking into account the attenu-ation and diffraction of interacting waves in the quasi-optical approximation. Expressions are given that describe the structure of the low-frequency field excited by high-frequency waves with arbitrary amplitude and phase distributions on the surface of pump transducers. Universal formulas for calculating directivity patterns are given. The dynamics of pattern formation is described. The results of calculating the regime of highly distorted pump waves containing shock fronts are presented.