This paper describes the evaluation of the dynamic behaviors of an isolated neoprene layer in the shape of a rectangular bumper inserted between two aluminum blocks. An experimental verification methodology is applied to obtain the damping ratios of rubber as a cushioning material and the isolation layer system. For the experiment, a finite element model with two degrees of freedom is established to compare the vibrational reduction characteristics. Dynamic responses are observed from the results of the finite element method by applying the general viscous damping ratio and Rayleigh proportional damping ratio. The results from the two individual damping ratios are similar to each other in terms of the frequency response function. Additionally, the natural frequencies and damping ratios decrease significantly as the portion of voids increases in the rectangular isolation layer. The procedure proposed herein allows one to predict the vibration-reduction behavior for various bump patterns of any damping material.