ELECTRICALLY-EVOKED OTOACOUSTIC EMISSIONS FROM THE APICAL TURNS OF THE GERBIL COCHLEA

Electrically evoked otoacoustic emissions were measured with current d elivered to the second and third turns of the gerbil cochlea. The emis sion magnitude and phase are dependent on the characteristic frequency (CF) of the stimulating microelectrode location. The death of the ani mal resulted in an initial increase in emission below the CF of the el ectrode location and a decrease in emission near the CF of the electro de location. The group delay of the electrically evoked emission phase data is twice as large as the acoustically evoked cochlear microphoni c (CM) data obtained by Schmiedt and Zwislocki [J. Acoust. Soc. Am. 61 , 133-149 (1977)]. This suggests the possibility of two separate propa gation modes for the forward and reverse traveling waves.