After having basic concept of second-order section, we can consider a cascade of second-order sections. The transfer functions H1,H2...Hn can be designed to approximate the response of the wave medium at the section outputs. Hm(s) can be the transfer function at the different place of x. Hdm(s) is the transfer function of differentiator output tap of different place of x. The figure 1 shows the transfer function in this project. The figure 2 shows the plot of 50 frequency responses of transfer functions of different place of x, the highest frequency as first one at x=base, the lowest frequency as last one at x=apex. As we can see, it is a cluster of low pass filters. Figure 3 shows the 50 frequency responses of transfer functions of differentiator output tap of different place of x. It is tuning at different frequency depending on different place of x. We can input signal with different frequencies and we can get the separated frequency signal at different taps. So the silicon cochlea model functions biological cochlea function. Next, we can see some test result of different input signal.
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