Estimation of outer-middle ear transmission using DPOAEs and fractional-order modeling of human middle ear

ESTIMATION OF OUTER-MIDDLE EAR TRANSMISSION USING DPOAES AND FRACTIONAL-ORDER MODELING OF HUMAN MIDDLE EAR by Maryam Naghibolhosseini Advisor: Glenis R. Long Our ability to hear depends primarily on sound waves traveling through the outer and middle ear toward the inner ear. Hence, the characteristics of the outer and middle ear affect sound transmission to/from the inner ear. The role of the middle and outer ear in sound transmission is particularly important for otoacoustic emissions (OAEs), which are sound signals generated in a healthy cochlea, and recorded by a sensitive microphone placed in the ear canal. OAEs are used to evaluate the health and function of the cochlea; however, they are also affected by outer and middle ear characteristics. To better assess cochlear health using OAEs, it is critical to quantify the impact of the outer and middle ear on sound transmission. The reported research introduces a noninvasive approach to estimate outer-middle ear transmission using distortion product otoacoustic emissions (DPOAEs). In addition, the role of the outer and middle ear on sound transmission was investigated by developing a physical/mathematical model, which employed fractional-order lumped elements to include the viscoelastic characteristics of biological tissues. Impedance estimations from wideband reflectance measurements were used for parameter fitting of the model. The model was validated comparing its estimates of the outer-middle ear sound transmission with those given by DPOAEs. The