Human middle-ear model with compound eardrum and airway branching in mastoid air cells

Abstract

An acoustical/mechanical model of normal adult human middle-ear function is described for forward and reverse transmission. The eardrum model included one component bound along the manubrium and another bound by the tympanic cleft. Eardrum components were coupled by a time-delayed impedance. The acoustics of the middle-ear cleft was represented by an acoustical transmission-line model for the tympanic cavity, aditus, antrum, and mastoid air cell system with variable amounts of excess viscothermal loss. Model parameters were fitted to published measurements of energy reflectance (0.25-13 kHz), equivalent input impedance at the eardrum (0.25-11 kHz), temporal-bone pressure in scala vestibuli and scala tympani (0.1-11 kHz), and reverse middle-ear impedance (0.25-8 kHz). Inner-ear fluid motion included cochlear and physiological third-window pathways. The two-component eardrum with time delay helped fit intracochlear pressure responses. A multi-modal representation of the eardrum and high-frequency modeling of the middle-ear cleft helped fit ear-canal responses. Input reactance at the eardrum was small at high frequencies due to multiple modal resonances. The model predicted the middle-ear efficiency between ear canal and cochlea, and the cochlear pressures at threshold.

High frequency transient-evoked otoacoustic emission measurements using chirp and click stimuli

“…They concluded that the similarity of SFOAE and DPOAE at high response frequencies suggests that middle-ear function limits reverse propagation of the evoked OAE back to the ear-canal microphone. This spectral pattern was similar to a model prediction (Keefe, 2015) of the reverse middle-ear pressure reflectance magnitude. This model was developed based on human temporal-bone measurements up to 8 kHz (Nakajima et al, 2008; Puria, 2003).…”

Morphological and morphometrical aspects of the auditory ossicles in goat (Capra hircus)

“…The main function of this ossicular assembly is to mediate the transmission of vibrations from the tympanic membrane through the handle of malleus ( Manubrium mallei ) and send them over towards the components of the internal ear, acting as a transformer of impedance of the air acoustic energy towards the fluids of the inner ear (Wilson, 1987),(Keefe, 2015).…”

Research on coupling effects of actuator and round window membrane on reverse stimulation of human cochlea

“…The network topology of the human ear impedance model is illustrated in the equivalent circuit model in Figure 4, which is combined with reports by different investigators, 22,28,29 and used to study the role of the third windows during the forward and reverse stimulations. 24 Briefly, the ear canal is modeled as a lossy cylindrical tube with a length of 2 × 10 −2 m and a cross-sectional area of 4.3 × 10 −5 m 2 .…”

“…The parameters of each component are listed in Table 1.Three transformers (tympanic membrane area A TM = 6 × 10 −5 m 2 , ossicular lever ratio of middle ear N ME = 1.3, and the stapes footplate area A SF = 3.14 × 10 −6 m 2 ) are arranged in the middle ear to obtain the pressure gain and impedance matching of the middle ear. 28,29 The outer ear and the middle ear correspond to the middle-ear impedance Z ME in Figure 3 during reverse stimulation.…”

“…Furthermore, compared with the human ear finite-element model, 25–27 the superiorities of the circuit model are that the impedance of the various components of the human ear can be specified quantitatively by experimental measurements. 28–30 Moreover, the circuit element helps to simulate the piezoelectric actuator and the inefficient coupling of the actuator to the RWM. 22,31…”