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.
Since the reptilian ear lacks a long cochlea, electrical tuning provides an alternative mechanism for perceiving differences in sound.
With a combination of voltage-gated calcium channels and calcium sensitive K+ channels, the cells set up an oscillation in voltage and oscillate in response to a depolarizing stimulus.
The delays can be as short as 0.7 ms or as long as 150 ms, whereas the Ca2+ entry always occurs within about 1 ms.[1] Thus, by varying the length of delay for K+ to leave, cells' ion concentrations can oscillate at specific frequencies.