ABSTRACT
At the end of 1950s, it seemed that cochlear mechanics was reasonably well understood. This feeling began to loose its footing near the end of 1960s when two perplexing discoveries took place, both subsequently verified on numerous occasions. Johnstone and Boyle (1967) found on live guinea pigs that the local maximum of basilar membrane vibration was substantially sharper than seen by Békésy (1960) in postmortem preparations. Their measurements were soon confirmed by Rhode (1971) on squirrel monkeys, who also determined directly on the same preparations the relationship between the in vivo and postmortem vibration maxima (Rhode, 1973). Almost at the same time, Spoendlin (1966, 1970) demonstrated that most of the afferent nerve fibers entering the cochlea ended on IHCs and only 5% to 10% innervated the OHC. The conclusion was inevitable that practically all auditory information reached the auditory nerve through the IHC.
