Figure 4. Responses of hair bundles from the bullfrog’s sacculus to sinusoidal frequency sweeps between 10 Hz and 200 Hz (A), 100 Hz and 500 Hz (B), and 1 kHz and 2 kHz (C).

Each stimulus was achieved by driving the laser’s source such that the amplitude of the sweep peaked at the maximum power output—12.5 mW for this fiber—while keeping its minimum above 0 mW. Each hair bundle was stimulated in the positive direction with 561 nm laser light; each trace is the average of 25 responses. Panel C portrays two 20 ms-long representative segments of the stimulus waveform, which would be unintelligible if displayed in full. These segments, located near the beginning and the end of the sweep, are aligned with the magnification of the simultaneous hair-bundle response (red dashed boxes).