This chapter focuses on aperiodic stochastic resonance induced by noise excitation and an aperiodic binary signal. We examine several typical nonlinear models to study this phenomenon, including bistable systems, asymmetric bistable systems, monostable systems, tri-stable systems, and fractional systems. Aperiodic stochastic resonance can be realized through an appropriate level of noise, as measured by the cross-correlation coefficient, and can also be enhanced by adjusting system parameters. Additionally, we address how vibrational resonance improves aperiodic stochastic resonance.