The mammalian cochlea has complicated nonlinear dynamics and exhibits various nonlinear responses to a sound stimulation. In this paper, a novel cochlea model the nonlinear dynamics of which is described by an asynchronous cellular automaton (triggered by multiple clocks) is presented. It is shown that the model can reproduce typical nonlinear responses observed in physiological measurements of a mammalian cochlea. Also, the model is implemented in a field programmable gate array and its operation is validated by laboratory measurements. It is shown that the model consumes much less hardware resources than a conventional representative simplified cochlea model.