A direct (mechanical) model uses the variables of air and water pressure, fluid velocity and viscosity, and displacement. An electrical analog model uses a different set of variables, namely, voltage and current. The outer and middle parts of the ear can be represented with a collection of coils, capacitors, and an ideal transformer to represent the leveraging effect of the ossicles. This circuit terminates with a capacitor representing the oval window. From there, the two channels are represented with a sequence of inductors and resistors for fluid flow within each channel with the two channels joined with a sequence of series resonant RLC circuits. Voltages across capacitances represent basilar membrane displacements. Element values along the cochlea are tapered in a logarithmic fashion to represent lowering frequency responses with distance.