Contralateral stimulation does not influence the suppression tuning curves of spontaneous otoacoustic emissions

Abstract

Little is known about the effects of contralateral acoustic stimulation on suppression tuning curves (STCs). Studies have examined the effect, but may have been confounded by activation of the acoustic reflex and the possibility of transcranial crossover of the contralateral signal. This study compared the sharpness (Q10 of STCs of SOAEs with and without contralateral stimulation that employed wideband noise. The intensity of the contralateral noise was well below the acoustic reflex threshold. The STCs of four female subjects were examined. The results revealed no change in the sharpness (Q10 of the tips of the STCs with and without contralateral stimulation. The lack of change in the STCs is inconsistent with prior findings based on recording obtained from single neurons in the auditory nerve in anesthetized animals and may reflect an insensitivity of the STC measures to dynamics of the efferent auditory system.