Final answer:
Hair cells in the organ of Corti have bundles of stereocilia. When vibrations cause these to tilt, tip links are stretched, opening ion channels, leading to hair cell membrane depolarization and auditory signals being sent to the brain.
Step-by-step explanation:
When the bundles of stereocilia of the hair cells tilt, the tip links are stretched, opening gated ion channels. In the organ of Corti, hair cells contain these stereocilia arranged from tallest to shortest. These stereocilia are mechanoreceptors responsible for detecting sound vibrations. As the hair cells vibrate due to sound waves, the movement of the basilar membrane results in the sliding of the tectorial membrane against the stereocilia. This action causes the stereocilia to bend towards their tallest member, subsequently stretching tip links between them and leading to the opening of ion channels. As ion channels open, the hair cell membrane is depolarized, leading to a nerve impulse sent to the cochlear nerve. The intensity of sound is gauged by the number of hair cells stimulated at a specific location in the cochlea.