Dr. John Guinan is an Investigator in the Eaton-Peabody Laboratories at Mass. Eye and Ear/Harvard Medical School. His primary research interest is in the area of auditory physiology. In particular, he studies cochlear mechanics, the effects of the olivocochlear efferent pathways of the cochlea, and how they affect human psychophysical performance. He is also interested in the methodology for clinical measurement of vestibular evoked myogenic potentials (VEMPs).

His work has provided a new concept of how the output of the cochlea is produced by the mechanical motions within the cochlea. He discovered that the inner hair cell stereocilia are driven by several separate cochlear mechanical vibration patterns.