The inner ear’s mechano-sensory “hair cells” rely on ion channels to convert sound-evoked mechanical vibrations of their hair bundles into electrical signals. Our group has recently discovered an unexpected transition between two functional states of the hair bundle at a threshold value of the electrical potential across the sensory hair-cell epithelium: a state of low mechanosensitivity (‘OFF STATE’), for which gating forces are weak and the hair bundle is quiescent, and a state of high mechanosensitivity (‘ON STATE’), for which gating forces are strong the hair bundle oscillates spontaneously. The aim of the traineeship will be to study this transition, determine whether it qualifies as first-order phase transition, and modulate its properties by external biochemical perturbations.