Difference between shock pulse and vibration

Consider a metal ball hitting a metal bar. At the moment of impact, a pressure wave spreads through the material of both bodies (1). The wave is transient (quickly dampens out). When the wave front hits the shock pulse transducer, it will cause a dampened oscillation of the transducer's reference mass. The peak amplitude is a function of the impact velocity (v).
During the next phase of the collision, both bodies start to vibrate (2). The frequency of this vibration is a function of the mass and the shape of the colliding bodies.