An Active, Reflectionless Transmission-Line Model of the Cochlea: Revisited

Reflectionless transmission-line model of the cochlea tells us that the characteristic impedance Z(0)(x, s) = root Z(p)(x, s)Z(s)(x, s), as a function of the distance x from the stapes and complex angular frequency s, should be independent of x, where Z(p)(x, s) and Z(s)(x, s) denote the distributed parallel impedance representing the BM resonator and the distributed series impedance representing the cochlear fluid, RL and TM impedances, respectively. In this paper, we first show that Z(s)(x, s) is regarded as an input impedance of a 2-port transducer containing two velocity-controlled force sources with its force factor Z(0)(s) and Z(p)(x, s) loading. Secondly, we introduce a distributed transducer-resonator model with its real-valued force factor Z(0) and nonlinear active resonator loading.