The acoustic response for waves normally incident upon a burning surface region is analyzed. The combustionprocess involves heat conduction within the solid, an irreversible surface pyrolysis process, and adistributed gas-phase reaction zone with conduction and diffusion. Linear differential equations determiningthe acoustic response are derived for arbitrary frequencies and simplified to a single second-order equationfor the case in which the frequency is small compared to the reciprocal of a characteristic gaseous reactiontime. An approximate analytical solution to this last equation, valid when the over-all activation energyfor the gaseous reaction is large, is shown to yield a simple formula for the admittance, which determinesthe acoustic response. This admittance formula implies that sound waves are attenuated at low frequenciesand, in most cases, amplified only when the frequency approaches the reciprocal of the reaction time. Inparticular, it is inferred that a pure solid ammonium perchlorate deflagration will not amplify acousticvibrations, and therefore, presumably, will not experience oscillatory combustion.