Ki. Mcanally et al., ACOUSTIC AND ELECTRIC FORWARD-MASKING OF THE AUDITORY-NERVE COMPOUND ACTION-POTENTIAL - EVIDENCE FOR LINEARITY OF ELECTROMECHANICAL TRANSDUCTION, Hearing research, 106(1-2), 1997, pp. 137-145
We investigated electro-mechanical transduction within the cochlea by
comparing masking of the auditory nerve compound action potential (CAP
) by acoustical and electrical maskers. Forward-masking of the CAP ref
lects the response to the masker of the cochlear location tuned to the
probe. Electrical stimulation was delivered through bipolar stimulati
ng electrodes within the basal turn of the scala tympani. The growth o
f masking of high-frequency probes which excite cochlear locations clo
se to the stimulating electrodes was similar for both acoustic and ele
ctrical maskers, suggesting a linear transduction of electrical energy
to mechanical energy. Exposure to intense acoustic stimulation caused
an equal loss of sensitivity to acoustic and electrical maskers. Mask
ing of lower-frequency probes by electrical maskers increased rapidly
with masker current, suggesting the direct electrical stimulation of n
eural elements. This masking was reduced by the administration of stry
chnine suggesting a contribution by the efferents towards masking of t
hese low-frequency probes.