English: (1) Mechanically gated ion channel (orange) is attached to a tip link, which consists of homodimers of cadherin 23 and protocadherin 15. (2) Inside a stereocilium, harmonin (green) links the cytoplasmic terminus of cadherin 23 (blue) to myosin 7A (black), a motor protein that tightly binds filamentous actin of the cytoskeleton (pink). (3) The vibrational energy in sound waves physically displaces the bundle toward the tallest stereocilium, increasing tension in the tip link that forces the ion channel to open. (4) Influx of the cations calcium (Ca2+; red) and potassium (K+; yellow) depolarizes the hair cell to trigger neurotransmitter release. Created with BioRender.com.