Effects of age-related tympanic-membrane material properties on sound transmission in the middle ear in a three-dimensional finite-element model. (March 2022)

• Record Type: Journal Article
• Authors: Yu, You-Cheng; Wang, Tang-Chuan; Shih, Tzu-Ching
• Is Part Of: Computer methods and programs in biomedicine. Volume 215(2022)
• Publication Date: 2022-03
• Subjects: Age-related hearing loss -- Standing wave -- Acoustics absorption coefficient -- Finite element method -- Harmonic acoustics coupling; Medicine -- Computer programs -- Periodicals; Biology -- Computer programs -- Periodicals; Computers -- Periodicals; Medicine -- Periodicals; Médecine -- Logiciels -- Périodiques; Biologie -- Logiciels -- Périodiques; Biology -- Computer programs; Medicine -- Computer programs; Periodicals; Electronic journals; 610.28
• DOI: 10.1016/j.cmpb.2022.106619
• Languages: English
• ISSNs: 0169-2607

Abstract

Highlights: The Young's modulus of the tympanic membrane plays an important role on sound transmission in the middle ear. The acoustic-structural coupled finite element modeling of human ear for sound transmission was demonstrated. A statistical analysis was performed investigating the effects of age-related Young's modulus on sound transmission. Abstract: Background and objectives: The Young's modulus of the tympanic membrane (TM) is an important modeling parameter in computer simulations of the sound transmission in the ear. Understanding the material mechanics of the TM is essential to improve the coupling between the tympanic membrane and the auditory ossicles. However, the impact of the age-related Young's modulus of the TM on sound transmission is not well known. The objective of this study was to use a comprehensive finite element (FE) model to assess the impact of Young's modulus on sound transmission from the ear canal to the stapes footplate over acoustic frequencies. Methods: The FE model of the ear canal, the middle ear, and the inner ear, was constructed. The model was constructed with identical geometries and boundary conditions, but with three different Young's moduli for the TMs. The auditory ossicles, suspensory ligaments and tendons, and manubrium were also modeled as isotropic elastic materials. Beside, we evaluated the age-related Young's moduli of the TMs on sound transmission with the FE element fluid-structural interaction (FSI) model under acoustic loading conditions. Results: The impact of the age-related Young's moduli on the sound pressure distributions in the ear canal was significant over two frequency ranges of 1.4–3.2 and 8.6–10 kHz. Meanwhile, the significant differences of the displacement of the stapes occurred at around 1.6 kHz, where the displacement of the stapes decreased from 0.352 nm to 0.287 nm. Conclusions: The FSI model could demonstrate the influence of Young's modulus of the TM on the transfer of sound-induced vibrations form the ear canal to the stapes footplate. The FE model may provide appropriate information to the medical device development of artificial ossicles and hearing aids. Graphical abstract: Image, graphical abstract