The phenomenon of parametric interaction of coupled waves exhibit a vital role in nonlinear acoustics. An attempt has been made to investigate numerically the possible instability and the parametric amplification of acoustic wave when laser beam interacts nonlinearly with a low frequency transverse acoustic wave in presence of transverse magnetostatic field in a heavily doped n-type piezoelectric semiconductor. Using a hydrodynamic model of a homogeneous plasma, the amplification of acoustic waves has been studied when a magnetostatic field is applied perpendicular to the direction of the pump wave propagation. For numerical simulation we use Newton-Raphson method for finding possibility of nonrealor imaginary roots. It is observed that imaginary part of the root becomes positive. So the instability of acoustic wave occurs and hence amplified for the present situation. The values of physical parameters are used for InSb crystal in this article.