A signal sensing module includes a substrate, a sensing electrode, a piezoresistive material layer and a sensing circuit. The substrate has a surface. The sensing electrode is disposed on the substrate and is exposed from the surface. The piezoresistive material layer is formed on the surface and covers the sensing electrode. The piezoresistive material layer has a resistance value. The sensing circuit is disposed in the substrate and adapted to sense a change of resistance value when a pressure wave passes through the piezoresistive material layer.