<Tr> <Th> NeuroLex ID </Th> <Td> nifext_61 </Td> </Tr> <Tr> <Td_colspan="2"> Anatomical terminology (edit on Wikidata) </Td> </Tr> <P> Hair cells are the sensory receptors of both the auditory system and the vestibular system in the ears of all vertebrates . Through mechanotransduction, hair cells detect movement in their environment . In mammals, the auditory hair cells are located within the spiral organ of Corti on the thin basilar membrane in the cochlea of the inner ear . They derive their name from the tufts of stereocilia called hair bundles that protrude from the apical surface of the cell into the fluid - filled cochlear duct . Mammalian cochlear hair cells are of two anatomically and functionally distinct types, known as outer, and inner hair cells . Damage to these hair cells results in decreased hearing sensitivity, and because the inner ear hair cells cannot regenerate, this damage is permanent . However, other organisms, such as the frequently studied zebrafish, and birds have hair cells that can regenerate . The human cochlea contains on the order of 3,500 inner hair cells and 12,000 outer hair cells at birth . </P> <P> The outer hair cells mechanically amplify low - level sound that enters the cochlea . The amplification may be powered by the movement of their hair bundles, or by an electrically driven motility of their cell bodies . This so - called somatic electromotility amplifies sound in all land vertebrates . It is affected by the closing mechanism of the mechanical sensory ion channels at the tips of the hair bundles . </P>

Where are the auditory receptors known as hair cells