The cochlea of the dolphin, Tursiops truncatus: hair cells and ganglion cells.
A study of the cochlear hair cells in Tursiops truncatus showed 3451 inner and 13,933 outer hair cells, for a total of 17,384. This total is of the same order of magnitude as the value of 14,975 for the human ear. Determination of the ganglion cell population for the dolphin gave a total of 95,004 cells, which is about three times as many as in man. The large number of hair cells in the dolphin ear suggests a high order of auditory proficiency in general, and especially a marked ability of tonal differentiation. The large ratio of ganglion cells to hair cells suggests unusual capabilities in the utilization of auditory information.
D000818:Animals; D003051:Cochlea / Q000166:cytology*; D004289:Dolphins / Q000033:anatomy & histology*; D005724:Ganglia / Q000166:cytology