  This work presents a quantitative theoretical study of the sound attenuation
in the unconventional multiband superconductor Sr2RuO4 below the
superconducting transition temperature Tc. Sound attenuation in this material
is shown to have the remarkable property of being able to identify different
nodal structures on different bands. The nodal structures on the \gamma band on
the one hand, and on the \alpha and \beta bands on the other, are both found to
be characterized by the existence of point nodes, but are significantly
different in their quantitative aspects.
