China
Africa
Explore chapters and articles related to this topic
Acoustic Criteria
Published in Randall F. Barron, Industrial Noise Control and Acoustics, 2002
The human ear is one of the more intricate and complex mechanical structures in the body. As shown in Fig. 6-1, the ear consists of three main parts: The outer ear, consisting of the pinna or visible ear, which acts as a horn to collect sound, and the meatus or auditory canal, which is terminated by the tympanic membrane or eardrum.The middle ear, which involves three small bones: the malleus or “hammer”, the incus or “anvil,” and the stapes or “stirrup”. These bones of the middle ear serve to transform the pressure variations in the air in the outer ear into mechanical motion. The eustachian tube in the middle ear serves to equalize the pressure between the outer and inner ear volumes.The inner ear, which contains the semicircular canals, the fluid gyroscope associated with maintaining balance of the body, and the cochlea, which analyzes, converts, and transmits information about sound from the outer ear to the brain through the auditory nerves.
Human Hearing and Noise Criteria
Published in David A. Bies, Colin H. Hansen, Carl Q. Howard, Engineering Noise Control, 2018
David A. Bies, Colin H. Hansen, Carl Q. Howard
Three tiny bones located in the air-filled cavity of the middle ear are identified in Figure 2.1 as the malleus (hammer), incus (anvil) and stapes (stirrup). They provide a mechanical advantage of about 3:1, while the relative sizes of the larger eardrum and smaller oval window result in an overall mechanical advantage of about 15:1. As the average length of the auditory canal is about 25 mm, the canal is resonant at about 4 kHz, giving rise to a further mechanical advantage about this frequency of the order of three.
The Human Ear
Published in David A. Bies, Colin H. Hansen, Engineering Noise Control, 2017
David A. Bies, Colin H. Hansen
Three tiny bones located in the air-filled cavity of the middle ear are identified in Figure 2.1 as the malleus (hammer), incus (anvil) and stapes (stirrup). They provide a mechanical advantage of about 3:1, while the relative sizes of the larger eardrum and smaller oval window result in an overall mechanical advantage of about 15:1. As the average length of the auditory canal is about 25 mm, the canal is resonant at about 4 kHz, giving rise to a further mechanical advantage about this frequency of the order of three.
Effect of ossicular chain deformity on reverse stimulation considering the overflow characteristics of third windows
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2022
Houguang Liu, Lin Xue, Jianhua Yang, Gang Cheng, Lei Zhou, Xinsheng Huang
To simulate the structural abnormalities of the ossicular chain, we used our previously reported FE model including the ear canal and middle ear (Zhou et al. 2016). In brief, the geometric model of the ear canal and middle ear are based on a series of histological section images collected from a human temporal bone (male, 60 years old, right ear). The volume of the air in the ear canal is 952.18 mm3, and the average length is about 26.32 mm. The volume of the malleus, incus, and stapes are 13.53, 15.54, and 2.95 mm3, respectively. The corresponding mass can be calculated from the measured dimensions. The definition of fluid-structure interaction surface, boundary conditions, and material properties of components in the model are consistent with those reported by Zhou et al. (2016). Figure 2 indicates the FE model of the ear canal and the middle ear. Coupled structural–acoustic analysis of the FE model was conducted using Abaqus (Dassault Systèmes, Johnston, RI, USA).
Design of a resilient ring for middle ear’s chamber stapes prosthesis
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2018
Emilia Anna Kiryk, Konrad Kamieniecki, Monika Kwacz
Stapes prostheses are used for surgical treatment of otosclerosis, which is an illness affecting auditory ossicles located in the middle ear. The ossicles (malleus, incus and stapes) link the outer and inner ear and transmit sound vibrations from the tympanic membrane to the oval window (OW). The stapes footplate (SF) is suspended on a highly elastic annular ligament (AL) in the OW niche. The AL enables the stapes to vibrate and to generate a pressure wave in the perilymph fluid. Otosclerosis immobilizes the stapes due to stiffening of the AL. This leads to a decrease in stimulation of the perilymph and manifests by conductive hearing loss (CHL). Otosclerosis is the cause of almost 22% of all CHL (Potocka et al. 2010).
Semi-automatic 3D reconstruction of middle and inner ear structures using CBCT
Published in Computer Methods in Biomechanics and Biomedical Engineering: Imaging & Visualization, 2023
Florian Beguet, Thierry Cresson, Mathieu Schmittbuhl, Cédric Doucet, David Camirand, Philippe Harris, Jean-Luc Mari, Jacques de Guise
The middle ear is a space filled with air located in the temporal bone between the outer ear and the inner ear. It contains a chain consisting of three movable ossicles: the malleus, the incus (Figure 1b) and the stapes (Figure 1c). The vibrations of the air captured by the eardrum are amplified along the ossicular chain and then transmitted to the inner ear via the oval window. The ossicles are eminently complex structures especially the stapes where a list of 14 probative measures has been determined (Farahani and Nooranipour 2008). In addition, each of these structures can be the cause of many hearing problems (Nager 1993).