Sensory biophysics. Physiological acoustics

Macroscopic anatomical data concerning the peripheral auditory system are currently well defined. The same cannot be said for the intimate structure of the cochlea, although discoveries made some fifteen years ago concerning structures of dimensions approaching the micrometer have led to major advances in our understanding of cochlear physiology. For example, the fundamental role of the outer hair cells has been partly revealed by the study of anatomical structures, but also by the discovery of phenomena that were totally unknown just a few years ago: otoemissions. This new knowledge (some of which is still controversial), however important it may be, is still insufficient to provide a satisfactory understanding of the functioning not only of the peripheral auditory system, but also of the central nerve pathways.

While deficits arising from damage to the outer ear (eardrum) or middle ear (ossicles) are generally accessible to surgical techniques, the same cannot be said of so-called "nerve" deafness, i.e. cochlear or retro-cochlear deafness. Major efforts are therefore still required to improve the therapeutic approach to hearing pathologies and, hopefully, to effectively rehabilitate these different forms of deafness.