This paper is concerned with the study of decay rates of the energy
associated to a semilinear wave equation with variable coefficients in a
smooth domain, subject to acoustic boundary conditions and dissipative
boundary memory feedback, where a general Borel measure is involved.
Under quite weak assumptions on this measure, we show the decay rates of
the semilinear system are described by solutions to a first order
nonlinear, dissipative ODE, which recovering and extending some of the
results from the literature. The method we used are energy multiplier
methods, geometric analysis and a standard integral inequality.