  We suggest a new type of radiation (acoustically induced radiation - AIR),
which is generated by ultrarelativistic particles channeling in crystal along a
crystal plane (or axis), which is bent by a transverse acoustic wave. The AIR
mechanism allows to make an undulator with characteristics inaccessible in the
undulators based on the motion of particles in the periodic magnetic fields and
also in the field of the laser radiation. The intensity of AIR can easily be
made larger than the intensity of the radiation in a linear crystal and can be
varied in a wide range by varying the frequency and the amplitude of the
acoustic wave.
