Electrical tuning is a mechanism by which vertebrates such as frogs and reptiles, which lack a long cochlea, discriminate sound. Mammals have long cochleae, and are able to distinguish different sounds by mechanisms such as mechanical tuning, in which the stiffness and length of hair cells’ stereocilia makes a given cell best suited to respond to a certain type of stimulus. The basilar membrane of animals with long cochleae also vibrates at different locations along the membrane in response to different frequency sounds. Since the reptilian ear lacks a long cochlea, electrical tuning provides an alternative mechanism for perceiving differences in sound.