The left panel represents the electrical part of the equations where V, R, C, and are, respectively, the membrane voltage, resistance and capacitance associated with the charge transferred by prestin, and the rate of the transferred charge (current). The right panel represents the mechanical part of the model equations, where the membrane resultant, N, and the rate of passive strain, , play the role of the voltage and current, respectively. The VE-box represents the viscoelastic transformation between the resultant, passive strain, and strain rate. The low central panel with the transformer (two coils) represents the electromechanical coupling with transformer ratio T between the resultant, N, and the mechanical component of the voltage, Vmech.