Cochlear microphonics have been explained in terms of a varying resistance at the hair cells that modulates resting currents and voltages in an electric network powered by biological dc “batteries.” In this paper, the distributed electric circuit of a 2‐mm‐long section of the first turn of the cochlea is approximated by a lumped network consisting only of linear elements, and including both fixed and variable capacitances across membranes as well as the variable resistance. When this circuit is driven by sinusoidal parameter variations, the voltage and current analogous to the cochlear microphonic and its concomitant hair‐cell current exhibit these steady‐state phenomena: (1) frequency‐sensitive gain; (2) frequency‐ and amplitude‐sensitive phase shift; (3) dc shifts of both polarities in response to purely ac stimulation, analogous to the summating potential; (4) waveform distortion. These results show that an additional stage of signal processing may exist between basilar‐membrane vibration and nerve spike trains, and certainly between basilar‐membrane vibration and observed cochlear potentials.