Figure 1.

Schematics of the sources of the CM, ANN, and CAP (A–C) and examples of ECochG responses obtained from two CI subjects (D,E). (A) Typical input-output function of hair cell transduction (top row) producing asymmetries in saturation points as a function of intensity (bottom row). (B) The ANN is produced by the convolution (^*) of a unit potential, or shape of an action potential as it appears at the round window, and the cyclic response to a low frequency in the population of unit responses, which is equivalent to the cycle histogram. The waveform expected is shown to the right. (C) The CAP is produced by the convolution (^*) of the unit potential and well-timed onset responses in the population. (D,E) Responses from two subjects to a low and a high frequency tones. For each subject and frequency, the first three rows are, respectively, the responses to condensation phase of stimulation, the difference between the responses to condensation and rarefaction phases (not shown), and the sum of the responses to the two phases. The fourth row depicts an “average cycle” which is the average of all cycles from condensation phase stimuli in a window after the CAP, and from rarefaction stimuli after flipping and shifting the response in time to match that of the condensation phase. See text for further explanation of features identified in these examples.