A–C, Membrane voltage responses to ±110 pA step injections; stimulus is shown at the top. A, Hair bundle exposed to 2.8 mm Ca2+ endolymph, generating 36 pA steady-state MET current. B, MET is mechanically blocked with a stiff probe, hyperpolarizing the cell and making it more nonlinear. C, MET is mechanically blocked and the cell is depolarized to best resonant voltage with 293 pA DC injection. Insets are first 30 ms. Calibration: 2 mV, 2 ms. D, Whole-cell voltage-clamp recording of a family of BK tail currents in response to a series of 10 ms voltage steps to various potentials; stimuli are shown at the top. E, Mean tail current activation curve (n = 17) and fit using a Boltzmann equation (V1/2 of −43 ± 2 mV; slope of 3 ± 1 mV). F, Comparison of the BK activation (gray) and the current–voltage relationship for a single cell: squares represent the resting potential for varying amounts of injected current. The axis is reversed from E.