cochlear hair cell stereocilia quantity inner hair cell stereociliary bundle morphology trait inner hair cell stereocilia quantity Trait.ontology The proportion or numbers of the nonmotile, actin-filled specialized microvilli (stereocilia) normally arrayed on the inner sensory epithelial cells of the cochlea, which are normally in synaptic contact with the auditory nerve. VT:0001301 inner hair cell sterocilia number