scholarly journals A note on the sound transmission of a spherical sound wave through a double plate structure

2021 ◽  
Vol 1 (4) ◽  
pp. 045601
Author(s):  
Xiaofeng Wang ◽  
Bilong Liu ◽  
Hongbo Zhang
Keyword(s):  
Sound Wave ◽  
Sound Transmission ◽  
Plate Structure

scholarly journals Improvement on sound transmission loss through a double-plate structure by connected with a mass–spring–damper system

2017 ◽  
Vol 9 (7) ◽  
pp. 168781401771394 ◽  
Author(s):  
Qibo Mao ◽  
Hui Shen
Keyword(s):  
Resonance Frequency ◽  
Natural Frequency ◽  
Transmission Loss ◽  
Sound Transmission ◽  
Sound Transmission Loss ◽  
Plate Structures ◽  
Air Mass ◽  
Plate Structure ◽  
Global Cost ◽  
Mass Spring

It is well-known that the acoustic performance of double-plate structures deteriorates rapidly around the mass–air–mass resonance frequency. In this study, a mass–spring–damper system connected between incident and radiating plates is used to improve the sound transmission loss at low-frequency ranges. First, a full structural-acoustic modal coupling model is developed to analyze the vibration and acoustical behaviour of the double-plate structures with mass–spring–damper system. Because there are in-phase or out-of-phase vibrations between double plates, tuning the natural frequency of the mass–spring–damper system exactly to the mass–air–mass resonance frequency cannot guarantee the maximum improvement on transmission loss. Optimal natural frequency and mass of the mass–spring–damper system were found as a solution of optimization problem with a global cost function defined as frequency-averaged sound transmission loss in the desired frequency range (around mass–air–mass resonance frequency). Finally, some numerical calculation results are presented. The calculated results show that the sound transmission loss of a double-plate structure can be improved significantly using optimally tuned mass–spring–damper system. The results indicate that an overall improvement of 12 dB below 1000 Hz can be achieved when the mass of the mass–spring–damper system equals to 10% weight of the double-plate structure.

Sound transmission of a spherical sound wave through a finite plate

2017 ◽  
Vol 410 ◽  
pp. 209-216 ◽  
Author(s):  
Bilong Liu ◽  
Yan Jiang ◽  
Daoqing Chang
Keyword(s):  
Sound Wave ◽  
Sound Transmission ◽  
Finite Plate

scholarly journals Sound transmission by chamber prosthesis of the middle ear

2020 ◽  
Author(s):  
Wiktor L. Gambin
Keyword(s):  
Middle Ear ◽  
Sound Wave ◽  
Round Window ◽  
Sound Transmission ◽  
Sound Frequency ◽  
Round Window Membrane ◽  
Stapes Footplate ◽  
Flow Through ◽  
Temporal Bones ◽  
Vibrating Plate

AbstractTests done on specimens cut from the temporal bones show, that the stapedotomy can be more effective, if instead of the piston prosthesis, the ear chamber prosthesis is used. In that case, the vibrations of the eardrum are transferred to a plate with attachment sticked to the incus. The plate is suspended on a membrane stretched on the base of conical chamber which is filled with a fluid and placed in the middle ear cave. The sound wave caused by a vibrating plate, is focused at the chamber outlet placed in a small hole drilled in the stapes footplate. As in the case of the piston prosthesis behavior of the round window membrane differs from that observed in the normal ear. The flow through a narrow outlet of the conical chamber makes a more deflection of the central part of the round window membrane. The properties of the prosthesis elements are close to those of the removed parts of the middle ear. In spite of this, one can observe a different sound transmission inside the ear. When the sound is higher than 1000 Hz, the vibration amplitude of the plate is 5-10 dB higher than that for the stapes footplate in the healthy ear. However, when the sound is lower than 1000 Hz, this amplitude is lower than that for the stapes footplate. To explain it, a simplified model of the sound propagation in the ear given in the prior work is used. To get a better agreement with the test results, the model takes into account a damping of the sound wave by the round window membrane. Next, the model is adapted to the ear with chamber prosthesis. The factors that may have an effect on the behavior of the sound wave are examined. The first is shortening of the incus. It increases the leverage of the ossicles and the force acting on the prosthesis plate compared to that in the normal ear. Next factor is a reduction of the mass of the vibrating plate what makes a growth of its resonance frequency. This slightly reduces the amplitude of the plate for the low sounds and increases it for the medium and the higher sounds. At end, the lack of the influence of the flow through the conical chamber on the sound wave energy is shown. The assumed model gives the rules for amplitudes of the chamber plate as functions of the sound frequency. Their values for the sound frequency from 400 Hz to 8000 Hz and its graphs are shown and compared with those for the stapes footplate in the normal ear. One can see that if the sound frequency is higher than 1000 Hz, then the chamber prosthesis makes higher amplitudes of the sound wave than the normal ear. To explain their drop for frequencies lower than 1000 Hz, needs more tests in this range.

Active Control of Sound Transmission Trough a Double Wall Structure

2011 ◽  
Vol 138-139 ◽  
pp. 858-863
Author(s):  
Qi Bo Mao
Keyword(s):  
Active Control ◽  
Transmission Loss ◽  
Piezoelectric Materials ◽  
Sound Transmission ◽  
Wall Structure ◽  
Control Performance ◽  
Velocity Sensor ◽  
Plate Structure ◽  
Modal Model ◽  
Double Wall

Based on coupling structural-acoustic modal model, using piezoelectric materials and loudspeaker/microphones as actuator/sensors, the analytical simulations are presented for the actively controlled the sound transmission through double plate structure. Firstly, the results show the potential for using PVDF sensors to improve sound transmission loss. Secondly, the effects of parameters of actuator/sensor and double plate structure on control performances are discussed. And some useful conclusions are obtained, for example, if volume velocity sensor is applied to radiating plate, transmission loss will improve significantly, no matter what type actuators (i.e. loudspeakers or PZT actuators on either plate) are used; symmetrical rectangular PVDF sensors should be applied on radiating plate; using loudspeaker/microphone configuration should be avoided for the same thickness double plate structure; the increased thickness of cavity leads to the better control performance.

Simulation of Sound Wave Propagation With Damping for Realistic Sound rendering for Games and Interactive Applications

2012 ◽  
Author(s):  
Bruno Moreira ◽  
Mauricio Kischinhevsky ◽  
Marcelo Zamith ◽  
Esteban Clua ◽  
Diego Brandao
Keyword(s):  
Wave Propagation ◽  
Sound Wave ◽  
Interactive Applications ◽  
Sound Rendering
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