Sound Vibration Research Articles

Psychoacoustic measurement of phase and level for cross-talk cancellation using bilateral bone transducers: Comparison of methods.

Two bone-conduction hearing aids (BCHAs) could deliver improved stereo separation using cross-talk cancellation. Sound vibrations from each BCHA would be cancelled at the contralateral cochlea by an out-of-phase signal of the same level from the ipsilateral BCHA. A method to measure the level and phase required for these cancellation signals was developed and cross-validated with an established technique that combines air- and bone-conducted sound. Three participants with normal hearing wore bone transducers (BTs) on each mastoid and insert earphones. Both BTs produced a pure tone and the level and phase were adjusted in the right BT in order to cancel all perceived sound at that ear. To cross-validate, one BT was stimulated with a pure tone and participants cancelled the resultant signal at both cochleae via adjustment of the phase and level of signals from the earphones. Participants achieved cancellation using both methods between 1.5 and 8 kHz. Levels measured with each method differed by <1 dB between 3 and 5 kHz. The phase results also corresponded well for the cancelled ear (11° mean difference) but poorly for the contralateral ear (38.4° mean difference). The first method is transferable to patients with middle-ear dysfunction, but covers a limited frequency range.

EXPERIMENTAL STUDIES ON THE NOISE AND VIBRATION OF A SPECIAL BORING MACHINE DUE TO FORMATION OF THE OPERATOR´S WORKPLACE SOUND FIELD

The purpose of this study is to measure the octave sound pressure levels and vibrations of a boring machine. A theoretical analysis of the sound pressure levels near the boring machine is performed. The measurement results are given. It was found that the workplace sound pressure levels exceed the sanitary standards, which suggests that the excessive noise levels are due to the exposure to the cutter sound radiation and the axis being machined.

ANALYSIS OF THE EXPERIMENTAL STUDY OF THE AXLE LATHE MACHINE VIBROACOUSTIC CHARACTERISTICS FOR WORKPLACE NOISE REDUCTION

The purpose of this study is to measure the octave sound pressure levels and vibrations of a stanopod lathe. A theoretical analysis of the sound pressure levels near the osteoprosche machines has been performed. The results of measurements are given. It is obtained that the levels of sound pressure at the workplace exceed sanitary standards. This suggests that the increased noise levels are due to the impact of the sound radiation of the cutting tool and the axis being machined.

Simulation of noise generated by a rotary-screw mover as a result of friction

The article describes the theoretical study of the noise generation parameters under friction of a base cylinder of a rotary-screw mover. The analysis of the influence of parameters of the base cylinder (diameter, angle of winding of the helical blade, length) and the vehicle motion parameters (speed, mass) on the noise level arising from mover interaction with a single obstacle is presented in the paper. The conditions for the occurrence of sound vibrations are shown. Analysis of the research results allows us to conclude that a significant noise level generated by the rotary-screw mover can take place only when the vehicle is moving on ice. The created model and the obtained results can be applied by developers of all-terrain vehicles.

Sound Generation under Rotary-Screw Propulsion Unit Base Cylinder Bending

Theoretical results of sound generation parameters under rotary-screw propulsion unit base cylinder bending are dealt with in this article. Base cylinder parameters impact such as diameter, wall thickness, length as well as such vehicle movement parameters impact as speed and mass on noise level appearing at rotary-screw propulsion unit passing a single obstacle are analyzed in the paper. Sound vibrations onset conditions are shown. Research results allow one to conclude that a considerable sound level generated by rotary-screw propulsion units can appear only when the vehicle mass to rotor diameter ratio is greater than 25. The model produced and the results obtained might be useful when designing cross-country vehicles.

Highly flexible all-nonwoven piezoelectric generators based on electrospun poly(vinylidene fluoride)

Acoustic energy is a sustainable and clean form of energy that is always being generated and wasted in our environment. Acoustic energy harvesting technology is a very promising substitute for fossil fuels and can serve as a suitable power supply for small electronic devices, owing to the high efficiency of piezoelectric devices. Thus, many studies have investigated the conversion of sound energy into electricity for power generation. In this study, we successfully fabricated an all-nonwoven polymer-based piezoelectric generator with a high acoustic energy conversion efficiency and high flexibility. A dispersion of single-walled carbon nanotubes (SWCNTs) was sprayed onto electrospun poly(vinylidene fluoride) (PVDF) webs to produce flexible and durable electrodes. The thickness and flexibility of the PVDF web used as the active piezoelectric layer were controlled by the spinning time. The effect of flexibility on frequency response, sound pressure response, output power, and energy harvesting characteristics was investigated by observing sound wave-induced vibration behavior and evaluating the output characteristics of the generators. The all-nonwoven polymer-based generator with the highest flexibility showed the highest output voltage overall due to its excellent vibration characteristics. Due to its effectiveness and durability suitable for acoustic energy harvesting, this all-nonwoven polymer-based generator can be useful for a wide range of applications, such as wearable electronics and large area flexible devices.

A water-retaining, self-healing hydrogel as ionic skin with a highly pressure sensitive properties

Abstract In recent years, artificial skin materials have attracted increasing attention of researchers in the field of wearable devices, artificial robot, artificial intelligence and other fields. However, the skin possesses multiple functions as the largest human organ, so there is still tremendous challenge in mimicking human skin. In this work, we successfully fabricated a skin sensor by constructed a sandwich structure to introduce a PDMS (polydimethylsiloxane) as water-retaining layer into sodium dodecylbenzene sulfonate (SDBS) and Bimetallic ion (Fe3+, Al3+) prepared flexible hydrogel to maintain moisture. The results manifested that he average dehydration rate of the hydrogel was reduced by more than 97%, due to the coating of PDMS, compared to the uncoated hydrogel. More importantly, the addition of SDBS results in a graded porous structure of the hydrogel, which facilitates the transport of ions and thus achieves pressure-sensitive behavior such as pulse rhythm, sound vibration and joint bending. Additionally, the hydrogel fabricated by the bimetallic ion as a crosslinking agent has high mechanical strength and self-healing properties that can self-heal within 2 s without any stimulation, wherein the self-healing efficiency is as high as 95%. As-prepared the artificial skin can not only be applied to various fields such as artificial intelligence, sensors, and personal medical care, but also promotes the further development and exploits great potential applications of smart skin.

ADATABLE INDUSTRIAL 4.0 : AN IMPROVEMENT DETECTED OBSOLETE BUSHING CONDITION ON RUBBER CURING MACHINE INDUSTRY

Bushing is a part of rubber curing machine that have function as cushion pin joint , generally make from a bronze material. Pin joint have a function to connected with 1 paired linkage arm with rotated crank gear of each via pin joint to get closing force at rubber curing machine when mould closed. When bushing condition at pin joint on rubber curing machine was not good caused by friction. It will make closing force linkage arm left and right ( 1 paired ) on rubber curing machine unbalanced. So it will make closing force to force closed rubber mould undistributed evenly, so it caused mould rubber closed with gap. This condition will make defect rubber product open mould after cured finished. In this case is important to find new methode detection and monitored bushing condition. This research was done by measured vibration around pin joint at linkage arm by taking data of sound and acceleration on the real object research and used 2D software simulator to measured bushing condition good or not. Acceleration measurement was done by measured at axis Y and Z by used accelerometer sensor, and accelero sensor on cell phone via sains journal android application. And collected the data stress value on linkage arm by used nidle dial gauge millimeter scale. By simulation software are measured acceleration at axis X and Y with good bushing condition or vise versa.The actual data that was collected : acceleration, sound vibration and stress value and simulated data by software to be compare the amplitude and choose the biggest amplitude as new methode measurement of vibration to detect and monitor bushing condition.From the result data, detection of vibration around pin joint by acceleration value by used accelerometer sensor measured at axis Y and Z more prefer with the other measurement methode.

The Development of Cooperative Channels Explains the Maturation of Hair Cell’s Mechanotransduction

Hearing relies on the conversion of mechanical stimuli into electrical signals. In vertebrates, this process of mechanoelectrical transduction (MET) is performed by specialized receptors of the inner ear, the hair cells. Each hair cell is crowned by a hair bundle, a cluster of microvilli that pivot in response to sound vibrations, causing the opening and closing of mechanosensitive ion channels. Mechanical forces are projected onto the channels by molecular springs called tip links. Each tip link is thought to connect to a small number of MET channels that gate cooperatively and operate as a single transduction unit. Pushing the hair bundle in the excitatory direction opens the channels, after which they rapidly reclose in a process called fast adaptation. It has been experimentally observed that the hair cell’s biophysical properties mature gradually during postnatal development: the maximal transduction current increases, sensitivity sharpens, transduction occurs at smaller hair-bundle displacements, and adaptation becomes faster. Similar observations have been reported during tip-link regeneration after acoustic damage. Moreover, when measured at intermediate developmental stages, the kinetics of fast adaptation varies in a given cell, depending on the magnitude of the imposed displacement. The mechanisms underlying these seemingly disparate observations have so far remained elusive. Here, we show that these phenomena can all be explained by the progressive addition of MET channels of constant properties, which populate the hair bundle first as isolated entities and then progressively as clusters of more sensitive, cooperative MET channels. As the proposed mechanism relies on the difference in biophysical properties between isolated and clustered channels, this work highlights the importance of cooperative interactions between mechanosensitive ion channels for hearing.

Preparation and properties of flame‐retardant damping polyurethane and its application in floating deck

Flame‐retardant modified polyurethane (PU) damping layers were prepared using the combination of expandable graphite (EG), aluminum hydroxide, and phosphorus‐nitrogen flame‐retardant HF600B. The mechanical, thermal, damping, and flame retardancy properties of PU damping layer and the sound insulation, vibration damping, and fire resistance of the deck components were studied systematically. The results revealed that the incorporation of flame retardant depressed the mechanical performance in general, and there was no significant change in damping property. At the same time, the residual char ratio of damping layer increased obviously with the addition of HF600B, the vertical burning rating was upgraded from V‐2 to V‐0 and passed the low flame test of marine materials. The A60 fire test showed that the floating deck system with damping layer had a maximum temperature rise of 75°C on the backfire surface during the test, which is much lower than 180°C required in the A60 grade fire resistance and has good fire resistance. Sound insulation test of the deck components showed that only a 2 mm damping layer increased the average sound insulation by 3 dB, especially in the low‐frequency range by about 8 dB. The vibration test showed that the damping effect of the floating damping deck system on the steel plate surface and the dressing surface is increased by 1.1 and 4.0 dB in the range of 10–200 Hz, 9.2, and 4.7 dB in the range of 200–1,500 Hz, respectively. POLYM. ENG. SCI., 59:2136–2147, 2019. © 2019 Society of Plastics Engineers

НАКОПИЧЕННЯ УШКОДЖЕНЬ В ОСНОВНИХ НЕСУЧИХ КОНСТРУКЦІЯХ СПОРУД, РЕЗЕРВ ПРАЦЕЗДАТНОСТІ

The article presents the results of experimental studies of the strength and deformability of load bearing structures made of wood under the action of static loads. In most major cities of Ukraine there are a huge number of buildings that have historical and architectural value. To preserve these structures for centuries, it is necessary to constantly receive such information about the state of their supporting structures for making timely decisions about reinforcement, replacement, overhaul, etc. In the materials of building structures, changes occur during the period of operation associated with the appearance, development and accumulation of structural damage. These damages cause submicron and microcracks, which are the result of external mechanical effects on the structure and therefore the transition to the boundary state is the result of a slow accumulation of damage. Having developed a technique for registering damage, you can get a tool that allows you not only to monitor the current state of the structure, but also to predict the change in its bearing capacity over time. In the period of operation there is a change in the structure of materials bearing structures The development of this process consists of several stages, the main of which are: deformation of interatomic bonds, nucleation of a sub-microcrack as a result of breaking macromolecules that form the walls of tracheids. This turns out to be suddenly and is accompanied by weak sound signals, resembling a micro explosion. The interaction of submicrocracks leads to their merging and the occurrence of microcracks, and the merging and increase of microcracks - to the occurrence of macrocracks (trunk crack), which leads to the destruction of the material. This dynamic process, depending on the size, nature and time of action of the load, may stabilize over time or, continuing, lead to the destruction of the structure. Mechanical and electrical devices currently used (indicators, strain gauges and other devices) are not suitable for detecting and recording material damage. For this purpose, it is necessary to use non- destructive research methods that allow continuous observation of submicro- and micro-processes that take place in the structure of the material of the structure. Such methods for estimating the residual life are currently being successfully applied only in aviation and on important equipment (thermal, hydraulic, nuclear power plants, etc.) The processes are obvious. There is a need to comprehensively investigate the issue of damage accumulation in wooden structures under load, and the associated processes of changing the cross-sectional area and carrying capacity and use the results of the study in the calculation of structures. This makes it possible to reduce the consumption of materials and make the sections of wooden structures more economical, and also allows you to avoid excessive margins. The direction of improving the methods of designing and calculating wooden structures and determining the residual life of the main wooden structures of structures are not yet reflected in the technical literature. In this regard, it requires a comprehensive study. To study the processes of damage accumulation in the material of construction, a method was used that does not destroy the structure. This is an acoustic emission method, which is associated with the propagation in the material of elastic waves caused by the dynamic local restructuring of its structure. Acoustic emission signals appear at the onset of micro and macro defects and accompany the entire process of material deformation. This allows you to diagnose the state of the structure, since the emission of sound vibrations can be detected at the stage when the structure as a whole is still operational.

Electrostatically tunable small-amplitude free vibrations of pressurized electro-active spherical balloons

Designing tunable resonators is of practical importance in active/adaptive sound generation, noise control, vibration isolation and damping. In this paper, we propose to exploit the biasing fields (induced by internal pressure and radial electric voltage) to tune the three-dimensional and small-amplitude free vibration of a thick-walled soft electro-active (SEA) spherical balloon. The incompressible isotropic SEA balloon is characterized by both neo-Hookean and Gent ideal dielectric models. The equations governing small-amplitude vibrations under inhomogeneous biasing fields can be linearized and solved in spherical coordinates using the state–space formalism, which establishes two separate transfer relations correlating the state vectors at the inner surface with those at the outer surface of the SEA balloon. By imposing the mechanical and electric boundary conditions, two separate analytical frequency equations are derived, which characterize two independent classes of vibration for torsional and spheroidal modes, respectively. Numerical examples are finally conducted to validate the theoretical derivation as well as to investigate the effects of both radial electric voltage and internal pressure on the resonant frequency of the SEA balloon. The reported analytical solution is truly and fully three-dimensional, covering from the purely radial breathing mode to torsional mode to any general spheroidal mode, and hence provides a more accurate prediction of the vibration characteristics of tunable resonant devices that incorporate the SEA spherical balloon as the tuning element.

Hollow-structured MXene-PDMS composites as flexible, wearable and highly bendable sensors with wide working range

Although versatile piezoresistive pressure sensors show a great potential as human motion detection and wearable smart devices, it is still an issue to widen their working range and enhance their sensitivity. Herein, hollow-structured MXene-polydimethylsiloxane composites (MPCs) are fabricated by utilizing nickel foam as the three-dimensional substrate for dip-coating of MXene sheets followed by infiltrating of polydimethylsiloxane and etching of the nickel foam substrate. The resultant MPC performs a wide working range with bending angles of 0° to 180°, an excellent long-term reliability up to 1000 cycles under the bending angles of 15°, 30° and 150°, and a stable durability with a bending angle of 30° in a frequency range from 0.05 to 2 Hz as a bendable piezoresistive pressure sensor, which is attributed to the formation of dense conduction paths due to the interconnection of MXene sheets during the deformation of MPC. The sensor also exhibits an extremely low detection limit of 10 mg for pressure detection. Interestingly, the slippage of adjacent MXene sheets is beneficial for monitoring slight vibration of equipments and detecting subtle human motions. Thus, the MPC sensor could be applied for stereo sound and ultrasonic vibration monitoring, swallowing, facial muscle movement, and various intense motion detections, demonstrating its great potential as wearable smart devices.

Dissipative effect in liquid under exposure to low-frequency sound vibrations

The article describes the formation of dissipative structures in a liquid in a metal bowl when exposed to lowfrequency sound vibrations. The fluctuating volumes in a thick layer of liquid, that is, clusters of molecules, which make an oscillatory motion and with a loss of stability occupying a new position in the liquid, are investigated. An external synchronous effect on a group of molecules can lead to increasing oscillations and loss of stability not only inside the liquid, but these groups of molecules can leave the liquid through the free surface.Friction on the outer surface of a bowl made of a conductive bronze-containing alloy, which initiates the occurrence of sound vibrations, gives rise to the appearance of new structures in the fluid inside the bowl. The thickness of the liquid layer is about 50 mm. The coordinated addition of energy to the oscillating microvolumes of water allows them to release their potential energy and turn it into kinetic. Water droplets ejected vertically indicate the existence of intense vertical movement of individual volumes of fluid which create new structures and cells, like Benard cells, resulting from heating and vertical convection, but smaller sizes. The observed phenomenon is similar to “cold boiling”. Here, probably, the potential energy of the compressed water particles is released under the influence of external sound vibrations. Sound analysis was performed using an audio editor for several experiments of various lengths.In this work, the dissipative effect in a thick layer of liquid when exposed to low-frequency sound vibrations and the appearance of structures identical to Benard cells in limited volumes of water (and not in a thin layer) is first investigated. It should be assumed that the effect of sound vibrations can lead to blood turbulization and a change in the physical state of living organisms, which in terms of physical effect can be similar to the state of blood boiling with a rapid rise from the depth of the sea. The phenomenon can be used for the intensification of heat and mass transfer in heat exchange installations.

Exposure of Murattal Al-Quran Audio Enhances Cisplatin Activity on Growth Inhibition and Cell Cycle Modulation on Hela Cells

Cancer is a disease characterized by abnormal cell mechanisms. The development of alternative cancer treatments is still needed. One of them is the music therapy. The music therapy uses sound vibrations to improve healing. Al-Quran, the Holy book of muslims, recites with measured recitation produces beautiful tones. Reading and recitating of Al-Quran is an important form of worship for which a Muslim can expect reward and benefit in the Hereafter. Al-Fatihah is one of surahs in Al-Qur'an that is often read by Muslims and used as a prayer for healing. The purpose of this study was to determine the effect of cytotoxic activity and cell cycle modulation on Hela cells with exposure of murattal Al-Quran and cisplatin combination. Audio exposure murattal Al-Fatihah and its combination with cisplatin to HeLa cells were tested using the MTT method assay. Induction of apoptosis and modulation of cell cycle evaluated by flow cytometry method. Treatment used 30 minutes Audio Murattal (AM), Cisplatin 10 µg/mL (Cis), and the combination of AM + Cis caused a decrease in the viability of HeLa cells respectively 80.14%, 69.86%, and 64.32%. The results of flow cytometry explained that in treatment of AM there was inhibition in the G2-M phase and induction of apoptosis in the M5 phase. Whereas in treatment AM + Cis inhibition occurs in the S, G2-M phase, and induction of apoptosis in the M5 phase. Audio Murattal Al-Quran presents cytotoxic effects on HeLa cells and to provide a synergistic impact on cisplatin so that disclosure therapy murattal can be recommended for supporting therapy in the treatment of cancer (supportive therapy).Keywords: Al-Quran, Audio murottal, HeLa Cells, Cell Viability, Flow cytometry

Fatigue testing of integrated thin film metal membranes for implantable biomedical pressure sensors

The longevity of thin film membranes is vital for the lifetime monitoring of fluid pressure inside the human body. However, aging and mechanical fatigue of the thin film material hinders the long-term reliability of implantable pressure sensors. Despite this, designers tend to neglect the fatigue life analysis of thin films in the design and fabrication of MEMS pressure sensors. Here, we present a low-cost fatigue testing system, which is custom designed from a modern multimedia speaker and subwoofer system. The subwoofer acts as an acoustic booster to amplify the sound vibrations into large stress amplitudes required for displacing the thin film membranes. A Keyence laser displacement sensor records the displacements of the thin films triggered in response to the sound-based stress amplitudes. A scanning electron microscope (SEM) is used in observing the surfaces of the thin films. An FEA parametric study and the fatigue testing results show significant correlations, except for the displacements values as the input Gaussian random vibrations are exaggerated in the experiments to visualize the bursting nature of the thin film membranes.

Some Effects of Sound and Music on Organisms and Cells: A Review

In animals, the sound vibrations are captured by the auditory cells, then transformed into electrical signals and conveyed to the nervous centers where they can be interpreted such as music. A lot of studies concern the effect of sound on the auditory cells and on the brain. Nevertheless, musical vibrations also affect other cells types in several organisms. These researches being not of the same nature, they need to be classified in order to provide elements of understanding the effects of music on cell biology. A lot of works were done on the effects of music on non-auditory cells. Effects on growth, apoptosis, immune system, protein activities in animal, plant and bacterial cells have been shown. These effects are of a physiological nature and require molecules and physicochemical mechanisms. Some works were performed on vegetal or animal total organisms, others directly on cells themselves, using cell cultures. Few works concern eukaryotic unicellular organisms. Results of these studies show music and sound exert effects on the physiology. But the experiments and results are still well disparate, with effects of different types of music on organisms via auditory on non-auditory cells, sometimes involving both auditory and non-auditory cells. Whatever the large variation of results, the study of the effects of sound and especially music on the cells is a subject on the future, considering the immense possibilities offered by music in modulating physiology, with potential therapeutic applications.

THEORETICAL AND EXPERIMENTAL RESEARCH OF VIBROACOUSTIC SYSTEMS WITH THE SMALL NUMBER OF ELEMENTS

The known methods of acoustical calculation in buildings not fully describe the phenomenon of sound transmission. This paper presents theoretical studies of the sound and vibration in building models, a method of statistical energy analysis (SEА), taking into account nonresonant phenomena and experimental testing of the specified parameters. The SEA-based equations are obtained for the energy balance, the solution of which allows to determine the sound energy in rooms and sound vibration in structures. The energy coupling coefficients, including those allowing for non-resonant sound transmission from adjacent acoustic subsystems, internal losses and the density of mode oscillation are calculated. The results of calculations and measurements of building model fragments, including identical and double partitions, are presented. The proposed method of calculation allows to predict the sound transmission through the partition with regard to adjacent structures.

A Single-Case, Mixed Methods Study Exploring the Role of Music Listening in Vibroacoustic Treatment

Chronic pain is a widespread issue accompanied commonly by depression and anxiety. Chronic pain has been shown to alter brain processing within the emotional and reward circuits, pointing towards a possible link between pain and comorbid mood disorders. Pain relief may be achieved by alleviating depressive and anxious symptoms. Relaxation is important for pain relief and eliciting relaxation through music listening is shown to relieve pain, depression, anxiety, and discomfort among others. In addition to auditory stimuli, Vibroacoustic treatment – the tactile application of low frequency sinusoidal sound vibration, plus music listening and therapeutic interaction – has been shown to be beneficial for relieving these symptoms. Although the combination of music listening and low frequencies has been previously explored, the role of the music listening within the vibroacoustic treatment context is unknown. A single-case, mixed method crossover study was conducted with a client suffering from chronic pain and comorbid mood disorders, four sessions with music listening, and four sessions without. Quantitative outcomes showed the client was more relaxed, less anxious, and had less pain after the music sessions. Qualitative findings showed that the client at first could not relax without the music listening because of her severe anxiety, but learned to use music as a distractor from her thoughts to relax, but also that silence was equally important for her; these hinged on her making the choice based on her needs, which had previously been difficult for her.

The Cultural Interpretations of “Golden Sound and Jade Vibration”

The Cultural Interpretations of “Golden Sound and Jade Vibration”