  Superradiant gain is the process in which waves are amplified via their
interaction with a rotating body, examples including evaporation of a spinning
black hole and electromagnetic emission from a rotating metal sphere. In this
paper we elucidate theoretically how superradiance may be realized in the field
of acoustics, and predict the possibility of non-reciprocally amplifying or
absorbing acoustic beams carrying orbital angular momentum by propagating them
through an absorbing medium that is rotating. We discuss a possible geometry
for realizing the superradiant amplification process using existing technology.
