  Isogeometric analysis (IGA) has proven to be an improvement on the classical
finite element method (FEM) in several fields, including structural mechanics
and fluid dynamics. In this paper, the performance of IGA coupled with the
infinite element method (IEM) for some acoustic scattering problems is
investigated. In particular, the simple problem of acoustic scattering by a
rigid sphere, and the scattering of acoustic waves by an elastic spherical
shell with fluid domains both inside and outside, representing a full
acoustic-structure interaction (ASI) problem. Finally, a mock shell and a
simplified submarine benchmark are investigated. The numerical examples include
comparisons between IGA and the FEM. Our main finding is that the usage of IGA
significantly increases the accuracy compared to the usage of $C^0$ FEM due to
increased inter-element continuity of the spline basis functions.
