Donald W. Nielsen
Central Inst. for the Deaf, 818 South Euclid Ave., St. Louis, MO 63110
For those in the society whose main interest lies in other acoustic fields, the presentation will review current topics in physiology of audition. Much basic physiological research has been focused on the micromechanics of the cochlea, the end organ of hearing. For many years the cochlear tuning process was throught to be passive and mechanical; however, recent studies indicate that active motion of one group of cochlear hair cells adds to and sharpens the tuning. The results and implications of studies of outer hair cell motion will be discussed. Also discussed will be the cochlear implant, a device that addresses injury or loss cochlear hair cells, the cause of most incurable forms of deafness. With this device, the electric fields of electrodes surgically implanted in the cochlea stimulate the nerve supply in the absence of normal hair cells. Also presented will be recent advances in molecular biology that attempt to induce growth or regrowth of hair cells in cochleae that have none.