  We study the validity of a Smoluchowski-Kramers approximation for a class of
wave equations in a bounded domain of $\mathbb{R}^n$ subject to a
state-dependent damping and perturbed by a multiplicative noise. We prove that
in the small mass limit the solution converges to the solution of a stochastic
quasilinear parabolic equation where a noise-induced extra drift is created.
