ABSTRACT
PURPOSE: The current study aims to evaluate gender variations in the efferent auditory system functioning in the ANSD population and compare them to normal hearing persons using contralateral suppression of spontaneous OAE (SOAEs). METHODS: For the current study, a total of 54 ears were considered prospectively. 27 ears with normal hearing (NH) sensitivity were in group I, while 27 ears with ANSD were in group II. All of the subjects had a regular audiological examination followed by synchronised SOAE recordings with and without broadband noise (in the contralateral ear) at 50 dB SPL and statistical analysis was carried out. RESULTS: Wilcoxon signed rank test revealed a significant decrease in SOAE amplitude with contralateral noise stimulation in NH, while no such trend was observed in ANSD. However, contralateral SOAE stimulation resulted in significant high-frequency shifts for both the ANSD and NH groups in the noise condition. In the comparison of gender effects on SOAE amplitude and frequency shifts using Mann-Whitney, no significant gender differences were seen. The lack of gender differences in SOAE suppression is explained based on global standing wave theory and local oscillator theory. CONCLUSIONS: Contralateral effect of noise on SOAE shows frequency shifts, but not amplitude shifts both of which are not affected by gender effects.
