China
Africa
Explore chapters and articles related to this topic
Human Hearing and Subjective Response to Sound
Published in Malcolm J. Crocker, A. John Price, Noise and Noise Control, 2018
Malcolm J. Crocker, A. John Price
The eardrum is connected to the malleus, the first of the three small bones known as the auditory ossicles (see Figure 2.2). The inner ear air cavity is connected to the back of the mouth by the Eustachian tube. The smallest of the ossicles, the stapes, which is about half the size of a grain of rice, is connected to a small oval window in the cochlea. The cochlea consists of spiral fluid-filled cavities inside the bone of the skull. The cochlea is comprised of a passageway which makes two and one half turns rather like a snail shell. Connected to the cochlea are the semicircular canals which are the balance mechanism and unrelated to hearing. The passageway of the cochlea is separated into lower and upper gallery by a membraneous duct figure 2.3). The upper and lower galleries are connected together only at the apex. Figure 2.4 is chematic representation showing the cochlea rolled."
Communication: Language and Speech
Published in Frank H Hawkins, Harry W Orlady, Human Factors in Flight, 2017
Frank H Hawkins, Harry W Orlady
While the vocal system generates speech, it is the auditory system which senses it and conveys vocal communication to the brain. As this mechanism is of vital importance in ensuring the effectivity of the communication, we should look at it more closely (Fig. 7.3). The external ear leads via an auditory canal to the tympanic membrane, or eardrum. The variations of pressure in the air cause this tightly stretched membrane to vibrate. Attached to this membrane, in the middle ear, are three tiny bones or ossicles called the hammer (malleus), the anvil (incus) and the stirrup (stapes). These bones are attached to the oval window of the inner ear, where a diaphragm sets in motion the fluid inside the cochlea. Within the cochlea is the Organ of Corti, a complex structure which contains the auditory nerve ends and the hair cells. The various components in this system can be seen as transformers and amplifiers.
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.
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
The result shows that the presence of the third windows overall increases the reverse stimulation’s performance, especially in the cases of ossicular chain fixation. Specifically, under normal condition, the magnitude of the reverse transfer function of the three-window model is greater than that of the two-window model in the low frequencies below 300 Hz. This is because the existence of the third windows causes volume velocity shunt flow, which increases the pressure difference between the scala vestibuli and scala tympani (Xue et al. 2020). With regard to the ossicular chain fixation, the malleus fixation and the incus fixation increase the reverse middle-ear impedance. The existence of the third windows increases the volume velocity shunt flow, so that the reverse transfer functions of the three-window model in these two cases are higher than that of the two-window model below 700 and 1000 Hz, respectively. For stapes fixation, we calculated two cases: an increase in single stiffness of the stapes and an increase in the impedance of the stapes. Under the condition of an increase in single stiffness of the stapes, compared with the two-window model's reverse transfer function, the three-window model's reverse transfer function has a higher magnitude below 2000 Hz. Above 2000 Hz, the three-window model exhibits low magnitude, which is mainly the result of the resonance response caused by the increase in the single stiffness of the stapes. Under the condition that an increase in the impedance of the stapes, the three-window model's reverse transfer function has higher magnitude in overall frequency ranges.
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 optimal parameters previously found were used for the overall validation of the method and its repeatability. The Table 2 presents the results of the global validation of the inner ear, the malleus and the incus. The mean and standard deviation of the four performance measures for the right and left ears of 15 patients are displayed.