There are many strange features in sound perception. These can be understood with self-tuned nonlinear oscillator model of cochlea which is self-tuned near Hopf bifurcation. This model enables us to understand dynamic response, high sensitivity of cochlea, two-tone suppression and residue perception of cochlea. Neural coding mechanism can be interpreted as mapping histogram of inter-spike intervals. We included inter-firing limit of neural pulse in which neuron can not response to external stimulus. This coincides with previous results and we could find parameter change may cause complexity in neural pulse signal.