scholarly journals External and middle ear sound pressure distribution and acoustic coupling to the tympanic membrane

2014 ◽  
Vol 135 (3) ◽  
pp. 1294-1312 ◽  
Author(s):  
Christopher Bergevin ◽  
Elizabeth S. Olson
Keyword(s):  
Pressure Distribution ◽  
Tympanic Membrane ◽  
Middle Ear ◽  
Sound Pressure ◽  
Acoustic Coupling

2D Modeling of the Human Ear Using the Equivalent Mechanical Impedance

2020 ◽  
Author(s):  
Chahbi Aziz ◽  
Assif Safaa ◽  
Faiz Adil ◽  
Hajjaji Abdelowahed.
Keyword(s):  
Tympanic Membrane ◽  
Middle Ear ◽  
Sound Pressure ◽  
Mechanical Impedance ◽  
Ossicular Chain ◽  
Body Parts ◽  
Frequency Range ◽  
Ear Canal ◽  
Finite Elements Analysis ◽  
Human Tympanic Membrane

Several mass–spring–damper models have been developed to study the response of the human body parts. In such models, the lumped elements represent the mass of different body parts, and stiffness and damping properties of various tissues. The aim of this research is to develop a 2D axisymmetric model to simulate the motion of the human tympanic membrane. In this contribution we develop our model using a Comsol Multiphysics software to construct a 2D axisymmetric objects, the acoustic structure interaction between the ear canal (field of propagation of the acoustic wave) and the structure of ear (skin, cartilage, bone, tympanic membrane) was solved using finite elements analysis (FEA). A number of studies have investigated the motion of the human tympanic membrane attached to the ossicular chain and the middle ear cavity. While, in our model the tympanic annular is assumed to be fixed and the loading of what comes behind the tympanic membrane as the ossicular chain, middle ear cavity and cochlea were replaced by the equivalent mechanical impedance of a spring mass damper system. The obtained results demonstrate that the maximum displacements of the umbo are obtained at the frequency range of [0.9 - 2.6] kHz, the sound pressure gain had the shape of peak with a maximum at [2 – 3] kHz frequency range. The umbo displacement depends on the damping coefficient d, and the sound pressure at the tympanic membrane was enhanced compared to that at the ear canal entrance.

On the hearing effects of a cholesteatoma growing: A biomechanical study

2021 ◽  
pp. 095441192110466
Author(s):  
Leonor Mendonça ◽  
Carla F Santos ◽  
Fernanda Gentil ◽  
Marco Parente ◽  
Bruno Areias ◽  
...  
Keyword(s):  
Tympanic Membrane ◽  
Middle Ear ◽  
Sound Pressure ◽  
Chronic Otitis Media ◽  
Biomechanical Study ◽  
The Finite Element Method ◽  
High Frequencies ◽  
Initial Stage ◽  
Hearing Function ◽  
Stapes Footplate

Chronic otitis media enables the appearance of a benign middle ear tumor, known as a cholesteatoma, that may compromise hearing. To evaluate the influence of a cholesteatoma growth on the hearing function, a computational middle ear model based on the finite element method was used and three different size of cholesteatoma were modeled. The cholesteatoma solidification and the consequent degradation of the ossicles were also simulated as two condition that commonly occurs during cholesteatoma evolution. A sound pressure level of 80 dB SPL was applied in the tympanic membrane and a steady state analysis was performed for frequencies from 100 Hz to 10 kHz. The displacements of both the tympanic membrane and the stapes footplate were measured. The results were compared with a healthy case and it was shown that the cholesteatoma development leads to a decrease in the umbo and stapes displacements. The ossicles degradation simulation showed the higher difference comparing with the cholesteatoma in an initial stage, with lower displacements in the stapes footplate mainly for high frequencies. The observed displacement differences are directly connected to hearing loss, being possible to conclude that cholesteatoma evolution in the middle ear will lead to hearing problems, mainly in an advanced stage.

Middle ear mechanics in normal, diseased and reconstructed ears

1998 ◽  
Vol 112 (8) ◽  
pp. 715-731 ◽  
Author(s):  
Saumil N. Merchant ◽  
Michael E. Ravicz ◽  
Susan E. Voss ◽  
William T. Peake ◽  
John J. Rosowski
Keyword(s):  
Structure Function ◽  
Tympanic Membrane ◽  
Middle Ear ◽  
Ossicular Chain ◽  
Acoustic Stimulation ◽  
Tympanic Membrane Perforation ◽  
Acoustic Coupling ◽  
Type Iv ◽  
Middle Ear Mechanics ◽  
Wide Range

AbstractA review of the structure-function relationships in normal, diseased and reconstructed middle ears is presented. Variables used to describe the system are sound pressure, volume velocity and acoustic impedance. We discuss the following(1) Sound can be transmitted from the ear canal to the cochlea via two mechanisms: the tympanoossicular system (ossicular coupling) and direct acoustic stimulation of the oval and round windows (acoustic coupling). In the normal ear, middle-ear pressure gain, which is the result of ossicular coupling, is frequency-dependent and smaller than generally believed. Acoustic coupling is negligibly small in normal ears, but can play a significant role in some diseased and reconstructed ears.(2) The severity of conductive hearing loss due to middle-ear disease or after tympanoplasty surgery can be predicted by the degree to which ossicular coupling, acoustic coupling, and stapes-cochlear input impedance are compromised. Such analyses are used to explain the air-bone gaps associated with lesions such as ossicular interruption, ossicular fixation and tympanic membrane perforation.(3) With type IV and V tympanoplasty, hearing is determined solely by acoustic coupling. A quantitative analysis of structure-function relationships can both explain the wide range of observed postoperative hearing results and suggest surgical guidelines in order to optimize the post-operative results.(4) In tympanoplasty types I, II and III, the hearing result depends on the efficacy of the reconstructed tympanic membrane, the efficacy of the reconstructed ossicular chain and adequacy of middle-ear aeration. Currently, our knowledge of the mechanics of these three factors is incomplete. The mechanics of mastoidectomy and stapedectomy are also discussed.

scholarly journals High-Speed Holographic Shape and Full-Field Displacement Measurements of the Tympanic Membrane in Normal and Experimentally Simulated Pathological Ears

2019 ◽  
Vol 9 (14) ◽  
pp. 2809 ◽  
Author(s):  
Haimi Tang ◽  
Payam Razavi ◽  
Koohyar Pooladvand ◽  
Pavel Psota ◽  
Nima Maftoon ◽  
...  
Keyword(s):  
Tympanic Membrane ◽  
Middle Ear ◽  
High Speed ◽  
Sound Pressure ◽  
Motion Pattern ◽  
Motion Patterns ◽  
Full Field ◽  
Field Displacement ◽  
Frequency Domains ◽  
Before And After

To improve the understanding of the middle-ear hearing mechanism and assist in the diagnosis of middle-ear diseases, we are developing a high-speed digital holographic (HDH) system to measure the shape and acoustically-induced transient displacements of the tympanic membrane (TM). In this paper, we performed measurements on cadaveric human ears with simulated common middle-ear pathologies. The frequency response function (FRF) of the normalized displacement by the stimulus (sound pressure) at each measured pixel point of the entire TM surface was calculated and the complex modal indicator function (CMIF) of the middle-ear system based on FRFs of the entire TM surface motions was used to differentiate different middle-ear pathologies. We also observed changes in the TM shape and the surface motion pattern before and after various middle-ear manipulations. The observations of distinguishable TM shapes and motion patterns in both time and frequency domains between normal and experimentally simulated pathological ears support the development of a quantitative clinical holography-based apparatus for diagnosing middle-ear pathologies.

scholarly journals Numerical Model on Sound-Solid Coupling in Human Ear and Study on Sound Pressure of Tympanic Membrane

2011 ◽  
Vol 2011 ◽  
pp. 1-13
Author(s):  
Yao Wen-juan ◽  
Ma Jian-wei ◽  
Hu Bao-lin
Keyword(s):  
Tympanic Membrane ◽  
Middle Ear ◽  
External Auditory Canal ◽  
Sound Pressure ◽  
Least Squares Method ◽  
Three Dimensional ◽  
Element Model ◽  
Response Analysis ◽  
Fe Model ◽  
Pressure Function

Establishment of three-dimensional finite-element model of the whole auditory system includes external ear, middle ear, and inner ear. The sound-solid-liquid coupling frequency response analysis of the model was carried out. The correctness of the FE model was verified by comparing the vibration modes of tympanic membrane and stapes footplate with the experimental data. According to calculation results of the model, we make use of the least squares method to fit out the distribution of sound pressure of external auditory canal and obtain the sound pressure function on the tympanic membrane which varies with frequency. Using the sound pressure function, the pressure distribution on the tympanic membrane can be directly derived from the sound pressure at the external auditory canal opening. The sound pressure function can make the boundary conditions of the middle ear structure more accurate in the mechanical research and improve the previous boundary treatment which only applied uniform pressure acting to the tympanic membrane.

scholarly journals Recovery from tympanic membrane perforation: Effects on membrane thickness, auditory thresholds, and middle ear transmission

2019 ◽  
Vol 384 ◽  
pp. 107813 ◽  
Author(s):  
Lingling Cai ◽  
Glenna Stomackin ◽  
Nicholas M. Perez ◽  
Xiaohui Lin ◽  
Timothy T. Jung ◽  
...  
Keyword(s):  
Tympanic Membrane ◽  
Middle Ear ◽  
Tympanic Membrane Perforation ◽  
Membrane Thickness ◽  
Auditory Thresholds ◽  
Membrane Perforation

Causes of failure of combined approach tympanoplasty in the treatment of acquired cholesteatomas of the middle ear and the mastoid

1995 ◽  
Vol 109 (8) ◽  
pp. 710-712 ◽  
Author(s):  
T. R. Kapur
Keyword(s):  
Tympanic Membrane ◽  
Eustachian Tube ◽  
Middle Ear ◽  
Squamous Epithelium ◽  
Combined Approach ◽  
Tube Obstruction ◽  
Incomplete Removal ◽  
Tube Dysfunction ◽  
Cause Of Failure ◽  
Causes Of Failure

AbstractForty cases of failed combined approach tympanoplasty were analysed. The commonest cause of failure was adhesions between the facial ridge and the tympanic membrane, causing segmental attico-mastoid malaeration in 51.3 per cent of cases followed-up continually. Other causes were, large dermoids, incomplete removal of squamous epithelium, and eustachian tube obstruction. Eustachian tube dysfunction did not appear to be a major cause of failure.

Anatomical Effects of Sudden Middle Ear Pressure Changes

1979 ◽  
Vol 88 (3) ◽  
pp. 368-376 ◽  
Author(s):  
A. Axelsson ◽  
J. Miller ◽  
M. Silverman
Keyword(s):  
Tympanic Membrane ◽  
Middle Ear ◽  
Round Window ◽  
Applied Pressure ◽  
Positive Pressure ◽  
Air Bubbles ◽  
Scala Tympani ◽  
Middle Ear Pressure ◽  
Contralateral Ear ◽  
Pressure Changes

Acute middle ear (ME) and inner ear changes following brief unilateral phasic ME pressure changes (up to ± 6000/mm H2O) were studied in the guinea pig. Middle ear findings included perforation of the tympanic membrane, serous and serosanguinous exudate and hemorrhage of tympanic membrane and periosteal vessels. Changes were related to magnitude of applied pressure. Perforation and hemorrhage were more commonly seen with negative rather than positive pressure. Air bubbles behind the round window were seen with positive pressures. Occasional distortion, but never perforation of the round window, was noted. Hemorrhage of the scala tympani was observed with both positive and negative pressures; scala vestibuli hemorrhage was found with negative ME pressure. In some instances pressure direction and magnitude related changes were seen in the contralateral ear.

Bioengineering. Effect of Depth of Conical-Shaped Tympanic Membrane on Middle-Ear Sound Transmission.

2001 ◽  
Vol 44 (4) ◽  
pp. 1097-1102 ◽  
Author(s):  
Takuji KOIKE ◽  
Hiroshi WADA ◽  
Toshimitsu KOBAYASHI
Keyword(s):  
Tympanic Membrane ◽  
Middle Ear ◽  
Sound Transmission
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