FIG. 3.
Outer hair cell (OHC) gain reduction in the AN model can account for medial olivocochlear reflex (MOCR) effects in basilar membrane (BM) responses. Data points are BM input–output functions from guinea pig measured by Russell and Muragasu (1997, their Fig. 1B). Responses to a tone at the characteristic frequency (CF, 15 kHz) were made without (circles) and with (triangles) shocks to the MOC bundle. The dashed red line is the prediction from the auditory nerve (AN) model at the level of the BM [d(t) in Fig. 1] at a CF of 15 kHz, with full OHC gain. To fit the solid blue line, the COHC parameter of the AN model was varied to find the optimum reduction in gain, which was 15 dB. Model BM output values were scaled by a fixed value (vertical shift) to best match the physiological absolute values in the no-shock condition.