Correlative study of sensory cell density and cochlear length in humans.

In the group of 50 cochlea from 28 men aged 38-73 years a great variability in the length of the cochlear duct was found ranging from 28.0 to 40.1 mm. The variability in the number of inner and outer hair cells is not so prominent and the same holds for the variability in density. Average densities of the inner and outer hair cells decrease with increasing cochlear length. However, the long cochleae have a greater number of hair cells which indicates that long cochleae have more sensory cells in a given frequency region.