scholarly journals МОДЕЛЮВАННЯ ЗАВИТКИ ВНУТРІШНЬОГО ВУХА ЛЮДИНИ

2012 ◽  
Author(s):  
S. A. Naida ◽  
О. A. Zubchenko
Keyword(s):  
Resonance Frequency ◽  
Sound Pressure ◽  
Basilar Membrane ◽  
Travelling Wave ◽  
Oval Window ◽  
Long Line

<p>There was conducted the simulations of a cochlea of an interior ear of the human by means of a long line. The following regularities of operation of a cochlea were determined: without the count of flexibilities Reissner's and basilar membranes swing pressure on walls of a cochlear course does not exceed 3,6 % from pressure in the field of an oval window; allocation of a differential of sound pressure fluctuates in a time with frequency; taking into account the slenderness of a membrane and dependence of a standing of resonances from <em>f </em>are spotted by non-uniformity of a basilar membrane; the differential travelling wave exists only near to a resonance on each  frequency where the amplitude buildup of oscillations to a maximum happens for many continuances of resonance frequency.</p><p>Small relative meaning of range of pressure of travelling wave could become the parent of that Peterson's and Bogert's work has not had the further evolution.</p>

Finite Element Model of Human Cochlea Considering of the Helicotrema Size

2013 ◽  
Vol 456 ◽  
pp. 576-581 ◽  
Author(s):  
Li Fu Xu ◽  
Na Ta ◽  
Zhu Shi Rao ◽  
Jia Bin Tian
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Basilar Membrane ◽  
Round Window ◽  
Element Model ◽  
Oval Window ◽  
Fe Model ◽  
Cochlear Duct ◽  
Human Cochlea ◽  
Set Up

A 2-D finite element model of human cochlea is established in this paper. This model includes the structure of oval window, round window, basilar membrane and cochlear duct which is filled with fluid. The basilar membrane responses are calculated with sound input on the oval window membrane. In order to study the effects of helicotrema on basilar membrane response, three different helicotrema dimensions are set up in the FE model. A two-way fluid-structure interaction numerical method is used to compute the responses in the cochlea. The influence of the helicotrema is acquired and the frequency selectivity of the basilar membrane motion along the cochlear duct is predicted. These results agree with the experiments and indicate much better results are obtained with appropriate helicotrema size.

scholarly journals Experimental Investigations of Different Loudspeakers Applied as Synthetic Jet Actuators

Actuators ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 224
Author(s):  
Paweł Gil ◽  
Joanna Wilk
Keyword(s):  
Thermal Resistance ◽  
Resonance Frequency ◽  
Sound Pressure Level ◽  
Heat Sink ◽  
Sound Pressure ◽  
Pressure Level ◽  
Synthetic Jet ◽  
Experimental Investigations ◽  
Driving Frequency ◽  
Jet Velocity

The paper presents the preliminary results of the experimental investigation of four various loudspeakers used for driving the synthetic jet actuator. The parameters, characteristic synthetic jet velocity, pressure inside the cavity, device sound pressure level (SPL), and the heat sink thermal resistance, were presented for various input power and driving frequency. The resonance frequency was determined based on electrical impedance. The highest synthetic jet momentum velocity was achieved at diaphragm resonance frequency. The maximum sound pressure level was observed, also at resonant frequency. For the same real power delivered to the actuator and for its resonance frequency, the heat sink thermal resistance had the lowest value for the specific loudspeaker. In turn, the synthetic jet velocity reached maximum for this actuator. For all actuators tested, the sound pressure level was dependent on momentum velocity.

Analysis for Vehicle Interior Noise Using Helmholtz Resonator

2005 ◽  
Author(s):  
Wakae Kozukue ◽  
Ichiro Hagiwara ◽  
Yasuhiro Mohri
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Resonance Frequency ◽  
Sound Pressure ◽  
Helmholtz Resonator ◽  
The Finite Element Method ◽  
Vehicle Interior ◽  
Vehicle Cabin ◽  
Set Up ◽  
Element Method

In this paper the reduction analysis of the so-called ‘booming noise’, which occurs due to the resonance of a vehicle cabin, is tried to carry out by using the finite element method. For the reduction method a Helmholtz resonator, which is well known in the field of acoustics, is attached to a vehicle cabin. The resonance frequency of a Helmholtz resonator can be varied by adjusting the length of its throat. The simply shaped Helmholtz resonator is set up to the back of the cabin according to the resonance frequency of the cabin and the frequency response of the sound pressure at a driver’s ear position is calculated by using the finite element method. It is confirmed that the acoustical characteristics of the cabin is changed largely by attaching the resonator and the sound quality is quite varied. The resonance frequency of the resonator can be considered to follow the acoustical characteristics of the cabin by using an Origami structure as a throat. So, in the future the analysis by using an Origami structure Helmholtz resonator should be performed.

Damage of the Auditory System Associated with Acute Blast Trauma

1989 ◽  
Vol 98 (5_suppl) ◽  
pp. 23-34 ◽  
Author(s):  
Michele Roberto ◽  
Roger P. Hamernik ◽  
George A. Turrentine
Keyword(s):  
Auditory System ◽  
Sound Pressure ◽  
Basilar Membrane ◽  
Organ Of Corti ◽  
Blast Waves ◽  
Mechanical Fracture ◽  
Sound Pressure Levels ◽  
Temporal Bones ◽  
Blast Trauma ◽  
The Impact

This paper reviews the results of several studies on the effects of blast wave exposure on the auditory system of the chinchilla, the pig, and the sheep. The chinchillas were exposed at peak sound pressure levels of approximately 160 dB under well-controlled laboratory conditions. A modified shock tube was used to generate the blast waves. The pigs and sheep were exposed under field conditions in an instrumented hard-walled enclosure. Blast trauma was induced by the impact of a single explosive projectile. The peak sound pressure levels varied between 178 and 209 dB. All animals were killed immediately following exposure, and their temporal bones were removed for fixation and histologic analysis using light microscopy and scanning electron microscopy. Middle ears were examined visually for damage to the conductive system. There were well-defined differences in susceptibility to acoustic trauma among species. However, common findings in each species were the acute mechanical fracture and separation of the organ of Corti from the basilar membrane, and tympanic membrane and ossicular failure.

A fully coupled subwavelength resonance approach to filtering auditory signals

2019 ◽  
Vol 475 (2228) ◽  
pp. 20190049 ◽  
Author(s):  
Habib Ammari ◽  
Bryn Davies
Keyword(s):  
Basilar Membrane ◽  
Travelling Wave ◽  
Frequency Separation ◽  
Mathematical Explanation ◽  
Layer Potential ◽  
Cochlear Hair Cells ◽  
Resonant Modes ◽  
Acoustic Pressure Wave ◽  
Frequency Map ◽  
Set Up

The aim of this paper is to understand the behaviour of a large number of coupled subwavelength resonators. We use layer potential techniques in combination with numerical computations to study an acoustic pressure wave scattered by a graded array of subwavelength resonators. Using this approach, the spatial frequency separation properties of such an array can be understood. Our set-up is inspired by the graded structure of cochlear hair cells on the surface of the basilar membrane. We compute the resonant modes of the system and explore the model's ability to decompose incoming signals. We propose a mathematical explanation for phenomena identified with the cochlea's ‘travelling wave’ behaviour and tonotopic frequency map.

scholarly journals The Biophysical Function of the Human Eardrum

2021 ◽  
Vol 3 (2) ◽  
pp. 103-107
Author(s):  
Janos Vincze ◽  
Gabriella Vincze-Tiszay
Keyword(s):  
Hair Cell ◽  
Inner Ear ◽  
Acoustic Signal ◽  
Basilar Membrane ◽  
Primary Auditory Cortex ◽  
Oval Window ◽  
Speech Comprehension ◽  
Sound Waves ◽  
Auditory Ossicles ◽  
Hearing System

The hearing analyzer consists of two main systems: the peripheral hearing system, formed of the outer ear, the middle ear and the inner ear and the central hearing system, which contains the nervous pathways which ensure the transmission of the nervous influx and the hearing area where the information is analyzed and the hearing sensation is generated. The peripheral hearing system achieves the functions of transmission of the sound vibration, the analysis of the acoustic signal and the transformation of the acoustic signal in nervous inflow and the generation of the nervous response. The human hearing is characteristics: 1. The eardrum vibrates from the sound waves; 2. Auditory ossicles amplify the stimulus; 3. In an oval window, the vibration is transmitted to the fluid space of the inner ear; 4. It vibrates the basilar membrane; 5. What is pressed against the membrane tectoria; 6. The stereocilliums of the hair cell bend, ion channels open; 7. Hair cell depolarizes; 8. Stimulus is dissipated in cerebrospinal fluid VIII (vestibulo¬cochlearis); 9. Temporal lobe primary auditory cortex (Brodman 41, 42); 10. Association pathways: speech comprehension (Wernicke area).

A Novel Analysis of the Mechanics of Cochlea, the Inner Ear

2003 ◽  
Author(s):  
Amitava Biswas
Keyword(s):  
Tympanic Membrane ◽  
Traveling Waves ◽  
Hair Cells ◽  
Basilar Membrane ◽  
Oval Window ◽  
Outer Hair Cells ◽  
Acoustic Energy ◽  
Longitudinal Contraction ◽  
Column System ◽  
The Impact

The human ear is often regarded as a paragon of mechanical engineering. To understand how the hearing system works, scientists have proposed detailed models of its specific aspects—the transfer of acoustic energy from the atmosphere to the tympanic membrane via the external ear; the coupling of the tympanic membrane to the oval window of the cochlea via ossicles; the resultant fluidic oscillations in the cochlear ducts; the formation of traveling waves in the basilar membrane of the cochlea; the mechanical stimulation of inner hair cells by the basilar membrane; and the consequential transduction of nerve impulses. Scientists have also proposed models to explain the phenomenon of enhancement of the traveling waves in the basilar membrane by synchronized co-contraction in the length of outer hair cells (OHCs). Although it is unrealistic that any OHC would contract in length without expanding in diameter, the models proposed by other analysts have so far incorporated the longitudinal contraction of OHCs only, suggesting that the impact of any diametric expansion of OHCs would be relatively trival. Here we show that the basilar membrane would behave like a Beam-Column system, which may be significantly influenced by the diametric expansion of OHCs.

Two-tone suppression in the basilar membrane of the cochlea: mechanical basis of auditory-nerve rate suppression

1992 ◽  
Vol 68 (4) ◽  
pp. 1087-1099 ◽  
Author(s):  
M. A. Ruggero ◽  
L. Robles ◽  
N. C. Rich
Keyword(s):  
Auditory Nerve ◽  
Outer Hair Cell ◽  
Basilar Membrane ◽  
Frequency Tuning ◽  
Low Frequency ◽  
Nerve Fibers ◽  
Oval Window ◽  
Outer Hair Cells ◽  
Probe Intensity ◽  
Rate Suppression

1. The vibratory response to two-tone stimuli was measured in the basilar membrane of the chinchilla cochlea by means of the Mossbauer technique or laser velocimetry. Measurements were made at sites with characteristic frequency (CF, the frequency at which an auditory structure is most sensitive) of 7-10 kHz, located approximately 3.5 mm from the oval window. 2. Two-tone suppression (reduction in the response to one tone due to the presence of another) was demonstrated for CF probe tones and suppressor tones with frequencies both higher and lower than CF, at moderately low stimulus levels, including probe-suppressor combinations for which responses to the suppressor were lower than responses to the probe tone alone. 3. For a fixed suppressor tone, suppression magnitude decreased as a function of increasing probe intensity. 4. The magnitude of suppression increased monotonically with suppressor intensity. 5. The rate of growth of suppression magnitude with suppressor intensity was higher for suppressors in the region below CF than for those in the region above CF. 6. For low-frequency suppressor tones, suppression magnitude varied periodically, attaining one or two maxima within each period of the suppressor tone. 7. Suppression was frequency tuned: for either above-CF or below-CF suppressor tones, suppression magnitude reached a maximum for probe frequencies near CF. 8. Cochlear damage or death diminished or abolished suppression. There was a clear positive correlation between magnitude of suppression and basilar-membrane sensitivity for responses to CF tones. 9. Suppression tended to be accompanied by small phase lags in responses to CF probe tones. 10. Because all of the features of two-tone suppression at the basilar membrane match qualitatively (and, generally, also quantitatively) the features of two-tone rate suppression in auditory-nerve fibers, it is concluded that neural two-tone rate suppression originates in mechanical phenomena at the basilar membrane. 11. Because the lability of mechanical suppression parallels the loss of sensitivity and frequency tuning due to outer hair cell dysfunction, the present findings suggest that mechanical two-tone suppression arises from an interaction between the outer hair cells and the basilar membrane.

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