Аннотации:
This review deals with experimental and theoretical aspects of acoustic superradiance, and also spontaneous coherent radiation of elastic multipoles. B. Peculiarities of sound superradiation excited by pulsed and stationary coherent external fields are considered. The creation of phonon avalanches as ac. The usefulness and perspectives of acoustic superradiance detection in the dynamical solid state problem investigations are also pointed out. © 1976.