Vibration Transducer Research Articles

A vibration transducer framework for the measurement and reconstruction of vibration signals via low-rate sampling

This study presents a novel, cost-effective, and highly accurate computer vision-based vibration transducer framework, enabling the measurement and reconstruction of vibration signals using video frames captured at a low frame per second (fps) relative to the Nyquist rate of the measured signal. In the proposed framework, an assembly consisting of several spring-mass systems serves as the primary sensor, while a camera module tracks the motion of the seismic masses as the secondary sensor. The setup, along with the modified compressive sensing equation (CS) equation, results in a transducer scheme that can recover the base motion signals from the displacement history of seismic masses sampled at rates much lower than the maximum predominant frequency of the original signal. The performance of the proposed transducer framework has been successfully verified by numerical simulations. In addition, an experimental study has been conducted in order to validate the concept under modelling and measurement error.

Study on the effect of the excited area on the vibration characteristics of a thin circular plate

Abstract In this paper, the vibration modes and radiated directivity of a thin circular plate excited by a sandwich longitudinal vibration transducer are studied. The finite element model is set up to study the effect of the contact area between the transducer and the circular radiation plate on the vibration modes and the radiation characteristics. The first six vibration modes of the thin vibration plate are analyzed, and the results show that the vibration modes of the area-excited thin circular plate are different from those of the free vibration thin circular plate and the point-excited thin circular plate. Simulation results show that under different contact areas, the thin circular plate vibrates in different modes. With the increase of the excitation area, the frequencies of each mode of the circular plate gradually increase. Moreover, the excited area also affects the radiative directivity. With the increase of the excited area, the main lobe width of the radiative directivity becomes narrower.

Design optimization and experimental verification of ultrasonic stack for micro hot embossing of polymers

Ultrasonic micro hot embossing (UMHE) is a prominent technique used in numerous sectors to produce micro parts since it is cheaper, faster, and more accurate. Amplitude uniformity is a crucial parameter in UMHE in order to manufacture micro parts with accurate dimensions and high-quality surfaces, even though limited research has been conducted on the uniformity of ultrasonic amplitude at the horn face during the embossing process. This paper presents an experimental and numerical study for designing an ultrasonic transducer and horn tailored to the micro hot embossing of polymer micro parts. A finite element (FE) simulation model combined with the Taguchi method has been developed to optimize the horn geometry and maximum amplitude uniformity. The Taguchi orthogonal array of 25 design runs has been generated and simulated using the developed FE modal analysis model, and then the optimized geometry was used to fabricate the horn. Applied torque and operating time calibrate and evaluate the transducer vibration characteristics. Experimental and simulation results revealed that the fabricated ultrasonic transducer and horn of a straight microfeature has a natural frequency of 28.8 kHz and has an 11 µm average peak-to-peak amplitude with 0.963 amplitude homogeneity along the microfeature face. The achieved frequency separation was greater than 0.85 kHz, whereas the gain ratio was 1.2. The design methodology developed in this paper showed great potential and has been numerically validated for various microfeature shapes across the horn face. Consequently, it can be applied to various ultrasonic applications beyond UMHE.

DIMENSONAREA ȘI CONSTRUCȚIA TRADUCTOARELOR PIEZOELECTRICE DE VIBRAȚII

The paper presents the construction of piezoelectric accelerometers, the mechano-electrical transfer mode, typical constructions, basic characteristics, and theoretical approaches to the vibration phenomenon appearing in accelerometry and calculation possibilities of the various characteristics of the transducers. In the second part of the paper, the functional testing of such a transducer is also presented, piezoelectric vibration transducers being useful for vibration determination and dynamic balancing of electric machines. In general, vibration transducers provide, through mechano-electrical conversion according to different principles, an electrical signal directly proportional to a vibration parameter (acceleration, travel speed, amplitude); depending on the principle, they can be piezoelectric, electrodynamic, inductive, capacitive, resistive or based on the Hall effect, with magnetic fluids, interferometric, laser, servo-accelerometers, etc. Since there is no universal accelerometer, each one is intended to encompass the characteristics of a concrete application best, the way of stressing the photosensitive medium in the first place, the design,, as well as the other characteristics, vary from one construction to another.

Requirements for vibroacoustic methods of the quality assessment of vehicles traction electric motors

The progression and refinement of traction electric motors play a pivotal role in the enhancement of vehicles. With constant advancements in power efficiency, diagnostic tools, and reliability, electric traction motors are becoming more economical in terms of operational costs. This article underscores the significance of methods used in assessing the technical proficiency of traction electric motors, coupled with their testing techniques. The vibration characteristics of these motors serve as a prime criterion in assessing their quality throughout their lifecycle – from design and manufacturing to operation. A groundbreaking proposition made in this article is the evaluation of electric traction motors’ health based on their vibration acceleration within an expansive frequency range of 5 Hz to 10 kHz. This contrasts the conventional approach which focuses on vibration speed in a restricted frequency spectrum up to 1000 Hz, as outlined by current standards. Such permissible vibration classes are essential in ensuring the high-quality design, technical finesse, and dependability of traction electric motors. Exceeding these vibration thresholds can result in rapid wear and tear, diminishing the motor’s reliability and lifespan. Hence, motors that surpass these permissible vibrations are not advised for vehicular use. Additionally, the article sheds light on requisite equipment controls for accurately gauging vibrations and noise levels in electric motors. Delving deeper into the nuances, the methods for mounting vibration transducers and electric motors on testing platforms are elucidated. These methods are pivotal in obliterating any hindrances that could impede the precise measurement of vibrations induced by an electric motor.

Introduction to the Technical Committee on Engineering Acoustics

This talk will introduce ongoing work in the Technical Committee on Engineering Acoustics (TCEA) of the Acoustical Society of America. Engineering Acoustics encompasses the theory and practice of creating tools to generate and investigate acoustical phenomena and then to apply the knowledge of acoustics to practical utility. This includes the design and modeling of acoustical and vibrational transducers, transducer arrays, and transduction materials or systems in all media and frequency ranges. It is also concerned with the design of acoustical instrumentation, metrology, and the calibration of those systems. It further considers all aspects of measurement, fabrication, and computational techniques as they relate to acoustical phenomena and their utility. The talk will provide an introduction of a broad range of research topics in TCEA, with specific highlights on exciting new areas of research.

The numerical analysis in heat transfer, fluid flow, and irreversibility of a pin-fin heatsink under the ultrasonic vibration with different transducer power assignment scenarios

The hydrothermal performance and entropy generation rate in a pin–fin heatsink were numerically investigated under different vibration transducer power distribution scenarios between 11 transducers located at 3 walls of the heatsink. Two cases were investigated; Case#A and Case#B which are different in 3 transducer locations on one wall of the heatsink. The highest convection coefficient (h) in Case#A was obtained for a variable power scenario, which escalated pressure drop (ΔP) by 91.94%. However, the highest h in Case#B was obtained for the constant power scenario. In addition, h, average temperature of CPU, and thermal resistance factor in Case#A are 5.84% higher than, 0.41% lower than, and 5.34% lower than those in Case#B. The PEC factor for Case#A is higher than unity (1.31) only under the constant power scenario, while the PEC of Case#B is higher than unity under different studied scenarios. Frictional irreversibility (Ṡfr) for Case#A was obtained as 1.45–74.56% higher than that for Case#B due to the swirl flow generated by the high-power transducers and creating the huge velocity gradients in Case#A. Nevertheless, the high flow mixing in Case#A leads to reducing the temperature gradients against Case#B, thereby thermal irreversibility (Ṡth) in Case#A is almost 7.05–19.69% lower than that of Case#B.

Vibration loading of self-propelled sprayer booms on ultra-low pressure tires

BACKGROUND: The article presents the results of experimental studies of the vibration loading of the booms of a self-propelled sprayer equipped with ultra-low pressure tires 1020x420-18 model Bel-79 when driving through single artificial bumps. Based on the results of the tests, the dependences of the influence of maximum vertical accelerations on the suspension of rods on the speed of movement at different air pressure in the tires and levels of filling the sprayer tank with process liquid were obtained. It has been established that with a decrease in the filling of the tank with process liquid and an increase in the speed of movement, the level of fluctuations on the sprayer booms proportionally increases relative to the full filling. When moving a self-propelled sprayer through artificial irregularities with the booms opened in the working position, located at a distance of 700 mm from the supporting surface, in the entire range of speeds from 3 m/s to 12 m/s, the oscillation amplitude at the ends of the booms did not exceed 80 mm.
 AIMS experimental evaluation of the impact of operational parameters of a mobile power tool equipped with ultra-low pressure tires on the vibration loading of sprayer booms.
 METHODS: Methods of laboratory and field research on the passage of a mobile power tool equipped with a boom sprayer through artificial bumps are given. The maximum vertical accelerations on the sprayer booms were determined using the ASSISTANT TOTAL instrument complex, which consists of a measuring unit with a vibration analyzer and an AR38R vibration transducer.
 RESULTS: The dependences of the influence of air pressure in ultra-low pressure tires and the speed of movement of the MEV-600 on the level of fluctuations of the sprayer booms when moving along artificial single irregularities are obtained. The minimum level of fluctuations on the rods at different air pressures in tires and different degrees of tank filling reaches at a MES speed of 9 m/s. The most vibration-loaded for sprayer booms is the empty driving mode.
 CONCLUSIONS: 
 The minimum level of fluctuations on the sprayer booms takes place in the speed range of 7.5 - 10.5 m/s. When the air pressure in the tires is reduced from 80 kPa to 20 kPa, the vibration loading of the rods is reduced by 2.8 times. An increase in vibration loading takes place in the range of filling level of the sprayer tank from 50% to empty. When moving along individual irregularities in the speed range from 3 m/s to 12 m/s, the sprayer booms were stably in a horizontal position, no intense vibrations and resonant modes of boom sections were observed.

Theoretical study on resonance frequencies of vibration modes of Janus-Helmholtz transducer

Janus-Helmholtz transducer has the characteristics of high-power and broadband transmission due to the coupling between the longitudinal resonance of the driver and the liquid cavity resonance of Helmholtz resonator. Traditional view holds that the low frequency resonance peak in the transmitting voltage response curve in water is fluid cavity mode of Helmholtz resonator while the high frequency resonance is the longitudinal mode of Janus transducer. However, in the past few decades, a large number of experimental studies have found that this conclusion is questionable. This work is to distinguish the two resonances in the response curve and the two vibration modes of Janus-Helmholtz transducer. Based on the Janus-Helmholtz transducer prototype reported in the literature, the resonance frequencies of the vibration modes of Janus-Helmholtz transducer are studied theoretically. The structure dimensions and material parameters of the prototype are listed in detail. The test results and simulation results of conductivity are also presented. The longitudinal resonance of the driver is determined by using the equivalent circuit method and finite element analysis. Radiation masses of both Janus transducer and typical longitudinal vibration transducer are also calculated to analyze the phenomenon of the sharp decrease of longitudinal resonance frequency in water. Acoustic modal analysis by using ANSYS software is performed to investigate the resonance frequency of complex Helmholtz resonator in Janus-Helmholtz transducer. Correction length on the vent introduced by external fluid sound radiation is used to obtain the accurate Helmholtz resonance frequency. The sound pressure distribution of Helmholtz resonator obtained through finite element method is investigated, and the correct equivalent formula for solving the Helmholtz resonance frequency is obtained. The results reveal that the first resonance in the response curve is driver resonance while the second one is Helmholtz resonance, which is contrary to the traditional view. The considerable reduction of driver resonance frequency in water is mainly due to the large radiation mass on the four large radiation surfaces of the Janus transducer, which also causes the sharp response of driver resonance. In Janus-Helmholtz transducer, there are two Helmholtz resonators with the same size, instead of only one resonator in the traditional view. The two resonance frequencies solved by the method proposed in this work are in good agreement with the test and simulation results. These conclusions play an important role in correctly understanding the structure and characteristics of Janus-Helmholtz transducer at source, as well as provide technical support for structural optimization and innovation, thus improving the acoustic emission properties of the transducer.

Radial sandwich radial-bending composite transducer designed based on acoustic black hole theory

A novel radial sandwich radial bending composite transducer is proposed based on the increasing amplitude of bending waves in the structure of an acoustic black hole (ABH). The transducer consists of a radial sandwich circular ring transducer and an outer acoustic black hole structure. The existence of the ABH structure realizes the conversion between radial vibration and bending vibration of the transducer, and improves the acoustic radiation performance of the transducer. Based on the one-dimensional acoustic black hole bending vibration theory, the bending vibration equation of the circular ABH structure is given. An analytical model of the ABH structure bending vibration is established by using the method of geometrical-acoustics, and the eigen frequency of its bending vibration is given. The relationship between the electromechanical conversion performance and the size of the transducer is discussed by using the finite element method, and the results show that when the eigen frequency of the bending vibration of the ABH structure is close to the resonant frequency of the transducer, the electromechanical coupling coefficient of the transducer reaches a maximum value. The radiation sound pressure field, radiation sound intensity, and radiation directionality of the transducer in the air are also analyzed by the finite element method. The results indicate that the presence of the ABH structure can improve the electromechanical conversion performance of the bending vibration of the transducer, enhance the acoustic radiation performance of the transducer, make the transducer exhibit radiation directionality and the lower order of the bending vibration mode of the ABH structure, the stronger radiation directionality of the transducer towards the left side and the right side. Finally, in order to verify the accuracy of the simulation and theory, we made a prototype transducer and carried out the experimental test of transducer electrical impedance and vibration mode. The measured results are in good agreement with the simulation results. The displacement distribution of the radiation surface of the transducer at resonance frequency is measured, which verifies the bending vibration mode of the ABH structure. This type of transducer is expected to be used as acoustic projector in the air or water.

Bond-pad damage in ultrasonic wedge bonding

Utilizing SEM/EDX analysis, microscale fracture at the bond-pad is detected when Cu wire is wedge bonded to a Cu or Al substrate. It is found that when a bond is fractured by pulling the wire similar to a pull test, a bulge on the wire and a cavity in the substrate are formed and fracture occurs in the original substrate. Using a 3D optical profiler, it is revealed that for a constant bond force and bond power, cavity's depth, radius, and surface area increase with bond time. These metrics are proposed as new factors for optimizing the wedge bonding process. A suitable combination of bonding parameters should maximize the cavity's surface area (as it pertains to bond's pull force) while minimizing the cavity's depth relative to the substrate's thickness to prevent damage in the substrate. Furthermore, employing Molecular Dynamics simulations, a possible plastic deformation mechanism for bond-pad damage is proposed. The mechanism points to the potential benefits of using a small-grain-sized substrate, a low transducer's vibration amplitude, and a high transducer's frequency for minimizing the cavity's depth.

Study of the phase characteristics of vibration sensors and conditions of orthogonalization of their measuring basis for the systems of vibration control and vibration testing of materials

To identify the most vibration-sensitive structures of the materials during vibration tests, it is necessary to determine the vibration vector in an orthogonal basis The effectiveness of the tests depends on the accuracy of the vector measurement. The transverse sensitivity of tri-axial vibration transducers, which have found vast application in various vibration measuring and material testing systems, leads to increased measurement errors and limits the frequency range of measurements. The errors can be reduced to almost zero using the proposed method of electronic orthogonalization, which involves rotation of the sensitivity vectors until they coincide with the orthogonal basis, resulting in zero transverse sensitivity. This approach has been successfully developed and works rather well in the low frequency band of the vibration transducer frequency response, wherein the amplitude-characteristics are linear and there is no phase shift in the channels. An emphasis is made on the influence of the phase characteristics of vibration sensors on the formation of orthogonalizing matrices that determine the requirements for an orthogonalizer. The structure of the installation for automated recording amplitude-frequency and phase-frequency responses of the vibration transducer, methodology and results of experimental study of a tri-axial piezoelectric accelerometer (TPA) with one inertia element and oblique-angle measuring basis are presented. The results obtained under vibration activated in three mutually perpendicular directions along the measuring axes show that the transducer measuring system is properly designed to provide for effective broadband orthogonalization of the measuring basis. The results obtained can be used to develop orthogonalizing transducers that eliminate transverse sensitivity in a wide frequency range, as well as to improve the design of sensors and their metrological characteristics.

Investigation to resonant frequency control of high power ultrasonic transducer based on the beating model

The response time of the resonant frequency tracking is a critical parameter to evaluate the performance of a high power ultrasonic system. In this investigation, we present a novel approach of frequency tracking based on the beating vibration model, which demonstrates improvement result compared with the conventional PLL method. We explore and enclose quantitatively the static and dynamic characteristics of the transducer at conditions of different temperatures, driving voltages and frequencies. It is found that the beating vibration occurs if the driving frequency is deviated from the optimal natural frequency. To reveal the mechanism of the beating vibration, an equivalent model is established. We propose a novel calculation algorithm of trust domain method to search accurately the resonant frequency in the response time, ensuring the resonant vibration of the ultrasonic transducer. The verification experiment is conducted in a PFGA and DSP controller, which verifies that the resonant frequency is determined within 30 ms. Our proposed approach can quickly decrease the beating time and fast achieving the resonant vibration, compared with the other frequency tracking methods.

Analysis and Optimization of Bending Vibration Modes of a Trilaminar Bending Ring Transducer with Unequal Diameters

In this study, we propose a fast calculation method that utilizes Kirchhoff’s hypotheses and electroelasticity theory to derive the resonant frequency, antiresonant frequency, and effective electromechanical coupling coefficient of a trilaminar bending ring transducer with unequal diameters. The accuracy of the theoretical method is validated through finite element analysis (FEM) and experimental tests. Furthermore, we perform optimization of the effective electromechanical coupling coefficient of the first-order bending vibration of the trilaminar bending ring transducer. Our optimization results indicate that, under the free inner and fixed outer boundary conditions, the effective electromechanical coupling coefficient initially increases to a maximum value and then rapidly decreases as r1/r2 increases. This behavior can be attributed to the out-of-phase vibrations and the in-phase electric field excitation on both sides of the bending ring vibration nodal circle. Finally, we present the optimized size configuration required to achieve the maximum effective electromechanical coupling coefficient. This study provides theoretical guidance for the design and optimization of trilaminar bending ring transducers with unequal diameters and has the potential to significantly advance the field of crosswell seismic source technology.

Vibroconverter mathematical model based on the levitation effect

Modern requirements for the safe operation of nuclear power plants dictate the need to introduce systems for early reactor plants state diagnosis. Vibrations have always been a threat to the safe nuclear power plants operation, therefore, solving the issues of improving the nuclear power plants vibronoise diagnostics accuracy, especially in the field of ultra-low frequencies, is an urgent task. The most promising way to solve the problem of flexible guides in electromechanical vibration transducers is the levitation effect, which makes it possible to completely eliminate mechanical contact and, accordingly, reduce the sensitivity threshold of the transducer. The article presents an analysis of existing vibration transducers and offers analogue and digital mathematical models of the magnetic levitation system, taking into account the influence of the electromagnetic force nonlinearity. The characteristics of such a nonlinear system are studied using the method of harmonic linearization, which makes it possible to obtain an equivalent linear system. At the same time, the third order terms of the electromagnetic force expansion in the Taylor series are taken into account, which made it possible to obtain a more accurate analogue the vibration transducer model. For the developed vibration transducer digital model, using the z-form method, a system function and the corresponding difference equation were obtained. Expressions and graphs of transient, pulse and frequency characteristics are derived for both analogue and digital vibration converter models, which allow us to conclude about the accuracy and adequacy of the developed digital model. Using obtained vibration transducer digital models will make it easier to model its operation and reasonably select the vibration transducer initial parameters.

Binocular Vision-Based Method Used for Determining the Static and Dynamic Parameters of the Long-Stroke Shakers in Low-Frequency Vibration Calibration

The long-stroke shaker is essentially required for the calibration of low-frequency vibration transducers, whose performance parameters have significantly impact on the calibration accuracy. The accurate measurement of these parameters is the prerequisite to establish a reliable vibration metrology and traceability system. Currently, an optical collimator or a reference accelerometer is applied to get the static parameter, the laser interferometry or tri- axial sensor-based method is used to obtain the dynamic parameters. However, the former relies on an extra device which increases the complexity and cost of calibration system, and the latter is always difficult to accomplish the accurate and efficient measurement of these parameters. In this study, a binocular vision-based long-stroke shaker performance measurement method is investigated, which has ability to determine the static and dynamic parameters simultaneously during the calibration. This vision method obtains the shaker's bending by measuring the inclinations at the different positions of its guideway, and achieves the amplitude characteristic, distortion, repeatability as well as transverse ratio measurements by accurately acquiring the spatial displacements at different frequencies. Comparison experiments with the two commonly used inclination esti- mation methods, and the laser interferometry and sensor- based method demonstrate that the investigated method is able to get the satisfactory accuracies both for the static and dynamic parameters of long-stroke shaker in vibration calibration.

A novel EDM method using longitudinal-torsional ultrasonic vibration (LTV) electrodes to improve machining performance for micro-holes

This study proposes a new EDM method using longitudinal-torsional ultrasonic vibration (LTV) electrodes for micro-hole machining to address the problems of debris removal and difficult working fluid exchange in micro-hole processing, which can enhance the micro-hole machining performance. A 38.9 kHz ultrasonic vibration transducer is developed for LTV electrodes, and the fluid distribution in the micro-holes gap is simulated when LTV electrodes were used to process micro-hole. The effect of ultrasonic amplitude on flow rate and debris removal efficiency is discussed. A study is conducted to analyze the morphogenesis of the electrode extremity and the micro-hole inlet/outlet at different amplitudes. This study finds that applying appropriate ultrasonic amplitude (2–4μm longitudinal amplitude, 0.2–0.35μm torsional amplitude) to the electrode effectively reduces the electrode tip and corner wear and the flanging burr of the micro-hole inlet/outlet. Compared EDM micro-hole machining with the rotating electrode only, the material removal rate (MRR) is increased by nearly two times with the simultaneous application of 4 μm longitudinal ultrasonic amplitude and 0.35μm torsional ultrasonic amplitude to the electrode, and reduction of electrode wear and micro-hole taper by approximately 60% and 80% respectively.

The effects of biodiesel produced from waste cooking oils on vibroacoustic properties of a heavy-duty diesel engine

This paper aims to investigate the vibroacoustic properties of biodiesel produced from waste cooking oils and petroleum-based diesel fuel depending on engine speed and load. Tests were conducted on a diesel engine with a 6 L cylinder volume which is used in today’s heavy-duty commercial vehicles. The engine tests were performed at various speeds and a constant engine load of 100 Nm. A vibration transducer and microphone were used to obtain the experimental data to determine vibroacoustic properties. The root mean square and coherence methods have been used for vibration analysis. The results show that the vibration amplitude of B100 at high engine speeds is slightly higher than that of pure petroleum-based diesel fuel (PBDF). B100 has a maximum 8.5% higher vibration amplitude relative to PBDF at an engine speed of 1500 rpm, where the engine is in the maximum torque intensity. Coherence analysis showed that the engine sound increased with increasing engine speed. The highest sound pressure level was 94.9 dB with B100 at an engine speed of 2000 rpm.

A computational method for modeling the multi-physical interactions of electromagnetic wind energy harvesters in tandem arrangement

This work presented a coupled formulation for evaluating the interaction of multiple inductive energy harvesters. The multi-physics problem of Fluid–Structure Interaction (FSI) and electromagnetic induction was addressed through a coupled model based on Computational Fluid Dynamics (CFD) approach and an electro-mechanical formulation.The Navier–Stokes equations were coupled to those of an oscillating rigid body and the Faraday’s law of induction for representing the electromagnetic vibration transducers. The proposed model was implemented by developing an OpenFOAM library. A finite element model (FEMM) was used for obtaining the magnetic flux derivative. The library was configured to map out the electromagnetic field and mechanical properties for each harvester and then, the electro-mechanical equations were solved by the explicit Runge–Kutta 2nd order scheme. For validating the coupled formulation, numerical simulations of an inductive energy harvester composed of two cylinders in tandem were conducted and compared to experiments published in the scientific literature. In order to demonstrate that the proposed formulation could be suitable for modeling complex configurations of harvesters, numerical simulations of three electromagnetic energy harvesters in array were executed and their performance was evaluated.

0486 The Effect of Acoustic Resonance Therapy on CPAP Adherence

Abstract Introduction CPAP is the gold standard therapy for OSA. Unfortunately, a significant percentage of patients do not tolerate CPAP therapy. Of those who struggle, a significant portion state that nasal congestion is a limiting factor. Acoustic Resonance Therapy (ART) is a new non-medication based treatment for nasal congestion. We sought to determine if patients struggling with Medicare CPAP adherence and reporting nasal symptoms would benefit by the addition of ART. Methods This was an IRB approved, prospective, non-randomized, controlled pre-/post-treatment study. Twenty-five adult participants with an OSA diagnosis (AHI>5) were enrolled by BetterNight (OSA management, San Diego, CA). Participants were new to CPAP within the previous 90 days and were not Medicare adherent. Participants self-reported nasal congestion as a significant contributor to non-adherence. After struggling with CPAP for varying durations, participants began the Sonu vibrational headband system (SoundHealth Systems, Los Altos, CA) for 15 minutes each evening, immediately prior to wearing CPAP, on 28 sequential nights. The Sonu headband is worn circumferentially just above the eyebrows. It utilizes a smartphone application and the self-facing camera to capture a facial scan and estimate sinonasal volume which determines the appropriate resonant frequencies and harmonics. Two vibrational transducers produce a signal in the audible acoustic range, from 80 Hz to 16 KHz. Total nasal symptom scores (TNSS) were obtained at baseline and self-reported daily during Sonu use. Results Participants were 64% male, age 48.2±12.9, AHI 31.6±22.7, BMI 32.5±6.6 (mean±SD). On days the 25 participants used CPAP, mean hours (h) of use increased during the intervention from 2.7h±1.9 to 4.0h±2.2 (48%,p=0.004). On a subset of 12 participants for whom 28 days of pre/post data was available, mean total hours of CPAP use increased from 64.8h±51.6 to 94.0h±59.4 (45%,p=0.0107). CPAP Medicare adherence increased from 30.0%±27.4 to 45.8%±35.0 (53%,p=0.0175). TNSS decreased from 4.8±2.2 to 2.1±1.9 (-56%,p=0.0016). Conclusion The use of the Sonu headband was associated with increased hours of CPAP use, improved CPAP adherence and reduced nasal symptoms. Support (if any)