What function do the OHCs have?
It is clear that the IHCs provide the vast majority, perhaps all, of the afferent information to higher neural centres.
Yet it had been known for a long time that damage to the OHCs alone resulted in a significant loss of hearing.
Direct measurements of basilar membrane motion in the early 1970’s indicated an important nonlinearity in basilar membrane motion.
Discovery of oto-acoustic emissions in the late 1970’s showed that the Organ of Corti was not simply a passive receiver of acoustic energy. There are also active elements feeding energy back into the system.