Abstract:
Introduction: Otoacoustic emissions (OAEs) are sounds that originate in cochlea and are measured in external auditory canal and provide a simple, efficient and non-invasive objective indicator of healthy cochlear function. Olivo cochlear bundle (OCB) or auditory efferent system is a neural feedback pathway which originated from brain stem and terminated in the inner ear and can be evaluated non-invasively by applying a contralateral acoustic stimulus and simultaneously measuring reduction of OAEs amplitude. In this study gender differences in TEOAE amplitude and suppression of TEOAE were investigated. Method: This study was performed at Akhavan rehabilitation centre belonging to the University of Social welfare and rehabilitation sciences, Tehran, Iran in 2011. 60 young adults (30 female and 30 male) between 21 and 27 years old (mean= 24 years old, SD=1.661) with normal hearing criteria were selected. Right ear of all cases were tested to neutralize side effect if there is any. Results: According to Independent T-test, TEOAE amplitude was significantly greater in females with mean value of 24.98 dB (p-value <0.001) and TEOAE suppression was significantly greater in males with mean value of 2.07 dB (p-value <0.001). Conclusion: This study shows that there is a significant gender difference in adult’s TEOAE (cochlear mechanisms) and TEOAE suppression (auditory efferent system). The exact reason for these results is not clear. According to this study different norms for males and females might be necessary.
Machine summary:
Iranian Rehabilitation Journal, Vol. 9, No. 14, 2011 Original Article Gender difference in TEOAEs and contralateral suppression of TEOAEs in normal hearing adults Farzaneh Zamiri Abdollahi*; Yones Lotfi, MD.
University of Social Welfare and Rehabilitation sciences, Tehran, Iran Introduction: Otoacoustic emissions (OAEs) are sounds that originate in cochlea and are measured in external auditory canal and provide a simple, efficient and non-invasive objective indicator of healthy cochlear function.
Olivo cochlear bundle (OCB) or auditory efferent system is a neural feedback pathway which originated from brain stem and terminated in the inner ear and can be evaluated non-invasively by applying a contralateral acoustic stimulus and simultaneously measuring reduction of OAEs amplitude.
Key words: TEOAEs, Contralateral suppression of TEOAEs, Efferent system, Androgen Submitted: 17 May 2011 Accepted: 012 Sep 2011 Introduction Otoacoustic emissions (OAEs) are sound waves that originate from cochlea and emit back into the external ear canal.
The Independent T-test results show that there is a significant difference between males and females in TEOAE amplitude and TEOAE suppression.
Et al (2006) continued study of gender effects on OAE and indicated that in human beings and Rhesus monkeys, Click-Evoked Otoacoustic emissions (CEOAEs) are more powerful in females than males, and this gender difference is the result of greater exposure to androgens prenatally in males (12).
Conclusion This study among others shows that there is a significant gender difference in TEOAE (which is by product of cochlear mechanisms) and TEOAE suppression (which is due to effects of auditory efferent system on cochlea).