Sensitivity of Acoustic Resonance Properties to a Change in Volume of Piriform Sinuses

2016 ◽  
Vol 821 ◽  
pp. 671-676 ◽  
Author(s):  
Vojtěch Radolf
Keyword(s):  
Computational Models ◽  
Vocal Tract ◽  
Acoustic Resonance ◽  
Mode Shapes ◽  
Finite Element Models ◽  
Antiresonance Frequency ◽  
Resonance Frequencies ◽  
Resonance Properties ◽  
1D Model

Piriform sinuses (PS), side branches of the human vocal tract, produce extra resonances and antiresonances which influence the quality of produced voice. These acoustic resonant characteristics can be numerically simulated by 3D finite element models of the vocal tract with lateral cavities. Computations that use these accurate methods are very time consuming, therefore this study introduces a simplified 1D mathematical model to analyse acoustical effects of side branches. Although the 1D model cannot capture higher-frequency transversal mode shapes, the resulted changes caused by piriform sinuses partially correspond to recent findings of 3D computational models. New pair of resonances around 5 kHz followed by an antiresonance frequency were detected in the results of the model including PS. The first four resonance frequencies lying below the first new resonance of PS decreased with increasing PS volume and similarly both the new resonances of PS. The higher original resonances increased with increasing PS volume.

Assessment of Tongue Position and Laryngeal Height in Two Professional Voice Populations

2020 ◽  
Vol 63 (1) ◽  
pp. 109-124
Author(s):  
Carly Jo Hosbach-Cannon ◽  
Soren Y. Lowell ◽  
Raymond H. Colton ◽  
Richard T. Kelley ◽  
Xue Bao
Keyword(s):  
Vocal Fold ◽  
Vocal Tract ◽  
Current Knowledge ◽  
Acoustic Resonance ◽  
Contact Dynamics ◽  
Voice Disorder ◽  
Music Program ◽  
Tongue Position ◽  
Singer Groups ◽  
Professional Voice

Purpose To advance our current knowledge of singer physiology by using ultrasonography in combination with acoustic measures to compare physiological differences between musical theater (MT) and opera (OP) singers under controlled phonation conditions. Primary objectives addressed in this study were (a) to determine if differences in hyolaryngeal and vocal fold contact dynamics occur between two professional voice populations (MT and OP) during singing tasks and (b) to determine if differences occur between MT and OP singers in oral configuration and associated acoustic resonance during singing tasks. Method Twenty-one singers (10 MT and 11 OP) were included. All participants were currently enrolled in a music program. Experimental procedures consisted of sustained phonation on the vowels /i/ and /ɑ/ during both a low-pitch task and a high-pitch task. Measures of hyolaryngeal elevation, tongue height, and tongue advancement were assessed using ultrasonography. Vocal fold contact dynamics were measured using electroglottography. Simultaneous acoustic recordings were obtained during all ultrasonography procedures for analysis of the first two formant frequencies. Results Significant oral configuration differences, reflected by measures of tongue height and tongue advancement, were seen between groups. Measures of acoustic resonance also showed significant differences between groups during specific tasks. Both singer groups significantly raised their hyoid position when singing high-pitched vowels, but hyoid elevation was not statistically different between groups. Likewise, vocal fold contact dynamics did not significantly differentiate the two singer groups. Conclusions These findings suggest that, under controlled phonation conditions, MT singers alter their oral configuration and achieve differing resultant formants as compared with OP singers. Because singers are at a high risk of developing a voice disorder, understanding how these two groups of singers adjust their vocal tract configuration during their specific singing genre may help to identify risky vocal behavior and provide a basis for prevention of voice disorders.

ADAPTAÇÃO E APLICAÇÃO DE MÉTODOS DE INTELIGÊNCIA COMPUTACIONAL PARA A ESTIMAÇÃO DE UMA FONTE DE POLUENTES EM ESTUÁRIOS

Engevista ◽  
2014 ◽  
Vol 17 (2) ◽  
pp. 152
Author(s):  
Radael De Souza Parolin ◽  
Pedro Paulo Gomes Watts Rodrigues ◽  
Antônio J. Silva Neto
Keyword(s):  
Computational Intelligence ◽  
Computational Models ◽  
Source Position ◽  
Iterative Search ◽  
Contaminant Source ◽  
Resources Management ◽  
Search Spaces ◽  
Grid Points ◽  
Computational Intelligence Methods

The quality of a given water body can be assessed through the analysis of a number of indicators. Mathematical and computational models can be built to simulate the behavior of these indicators (observable variables), in such a way that different scenarios can be generated, supporting decisions regarding water resources management. In this study, the transport of a conservative contaminant in an estuarine environment is simulated in order to identify the position and intensity of the contaminant source. For this, it was formulated an inverse problem, which was solved through computational intelligence methods. This approach required adaptations to these methods, which had to be modified to relate the source position to the discrete mesh points of the domain. In this context, two adaptive techniques were developed. In one, the estimated points are projected to the grid points, and in the other, points are randomly selected in the iterative search spaces of the methods. The results showed that the methodology here developed has a strong potential in water bodies’ management and simulation.

Split beam method for determining mode shapes of cantilever beams under multiple loading conditions

2021 ◽  
pp. 107754632110276
Author(s):  
Jun-Jie Li ◽  
Shuo-Feng Chiu ◽  
Sheng D Chao
Keyword(s):  
Operation Mode ◽  
Point Contact ◽  
Mode Shapes ◽  
Cantilever Beams ◽  
Loading Conditions ◽  
Mechanical Responses ◽  
Relative Contribution ◽  
Resonance Frequencies ◽  
Beam Method ◽  
Multiple Loading

We have developed a general method, dubbed the split beam method, to solve Euler–Bernoulli equations for cantilever beams under multiple loading conditions. This kind of problem is, in general, a difficult inhomogeneous eigenvalue problem. The new idea is to split the original beam into two (or more) effective beams, each of which corresponds to one specific load and bears its own Young’s modulus. The mode shape of the original beam can be obtained by linearly superposing those of the effective beams. We apply the split beam method to simulating mechanical responses of an atomic force microscope probe in the “dynamical” operation mode, under which there are a stabilizing force at the positioner and a point-contact force at the tip. Compared with traditional analytical or numerical methods, the split beam method uses only a few number of basis functions from each effective beam, so a very fast convergence rate is observed in solving both the resonance frequencies and the mode shapes at the same time. Moreover, by examining the superposition coefficients, the split beam method provides a physical insight into the relative contribution of an individual load on the beam.

Application of partial eigenvalue assignment techniques to dampen electromechanical oscillations in multi-machine power systems

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Erick Baleeiro da Silva ◽  
José Mário Araújo
Keyword(s):  
Power Systems ◽  
The Other ◽  
Mode Shapes ◽  
Eigenstructure Assignment ◽  
Power System Stabilizers ◽  
Control Effort ◽  
Electromechanical Oscillations ◽  
Oscillation Modes ◽  
Partial Controllability

AbstractIn this study, a methodology for partial eigenstructure assignment (PEVA) is applied to dampen electromechanical oscillations in electrical multi-machine power systems. The approach is anchored in allocating a small number of undesirable eigenvalues, for example, which are poorly damped, preserving the other eigenvalues in the system - the so-called no-spillover spectrum. The new position of the selected eigenvalues is carried out based on the partial controllability analysis of the system, in order to minimize the control effort. Simulation examples using a system with 68 buses, 16 generators and five areas showed that the presented methodology is efficient in dampening the local and inter-area oscillation modes when compared to the classic power system stabilizers (PSS). The quality of the solution is illustrated through computer simulations, eigenvalues tables and mode-shapes.

scholarly journals Sounding out falsified medicines from genuine medicines using Broadband Acoustic Resonance Dissolution Spectroscopy (BARDS)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anas Alfarsi ◽  
Céline Caillet ◽  
Garry Fawbert ◽  
Simon Lawrence ◽  
Jacob Krüse ◽  
...  
Keyword(s):  
Active Ingredient ◽  
Lower Cost ◽  
Principal Component ◽  
Acoustic Resonance ◽  
South East Asia ◽  
Acoustic Signatures ◽  
Falsified Medicines ◽  
Acoustic Phenomenon ◽  
The Eu

AbstractThe trade in falsified medicine has increased significantly and it is estimated that global falsified sales have reached $100 billion in 2020. The EU Falsified Medicines Directive states that falsified medicines do not only reach patients through illegal routes but also via the legal supply chain. Falsified medicines can contain harmful ingredients. They can also contain too little or too much active ingredient or no active ingredient at all. BARDS (Broadband Acoustic Resonance Dissolution Spectroscopy) harnesses an acoustic phenomenon associated with the dissolution of a sample (tablet or powder). The resulting acoustic spectrum is unique and intrinsic to the sample and can be used as an identifier or signature profile. BARDS was evaluated in this study to determine whether a product is falsified or genuine in a rapid manner and at lower cost than many existing technologies. A range of genuine and falsified medicines, including falsified antimalarial tablets from south-east Asia, were tested, and compared to their counterpart genuine products. Significant differences between genuine and falsified doses were found in their acoustic signatures as they disintegrate and dissolve. Principal component analysis was employed to differentiate between the genuine and falsified medicines. This demonstrates that the tablets and capsules included here have intrinsic acoustic signatures which could be used to screen the quality of medicines.

scholarly journals A Randomized Controlled Trial of Two Semi-Occluded Vocal Tract Voice Therapy Protocols

2015 ◽  
Vol 58 (3) ◽  
pp. 535-549 ◽  
Author(s):  
Mara R. Kapsner-Smith ◽  
Eric J. Hunter ◽  
Kimberly Kirkham ◽  
Karin Cox ◽  
Ingo R. Titze
Keyword(s):  
Quality Of Life ◽  
Vocal Tract ◽  
Controlled Trial ◽  
Voice Quality ◽  
Voice Handicap Index ◽  
Voice Therapy ◽  
Control Group ◽  
Perceptual Evaluation ◽  
Therapy Program

PurposeAlthough there is a long history of use of semi-occluded vocal tract gestures in voice therapy, including phonation through thin tubes or straws, the efficacy of phonation through tubes has not been established. This study compares results from a therapy program on the basis of phonation through a flow-resistant tube (FRT) with Vocal Function Exercises (VFE), an established set of exercises that utilize oral semi-occlusions.MethodTwenty subjects (16 women, 4 men) with dysphonia and/or vocal fatigue were randomly assigned to 1 of 4 treatment conditions: (a) immediate FRT therapy, (b) immediate VFE therapy, (c) delayed FRT therapy, or (d) delayed VFE therapy. Subjects receiving delayed therapy served as a no-treatment control group.ResultsVoice Handicap Index (Jacobson et al., 1997) scores showed significant improvement for both treatment groups relative to the no-treatment group. Comparison of the effect sizes suggests FRT therapy is noninferior to VFE in terms of reduction in Voice Handicap Index scores. Significant reductions in Roughness on the Consensus Auditory-Perceptual Evaluation of Voice (Kempster, Gerratt, Verdolini Abbott, Barkmeier-Kraemer, & Hillman, 2009) were found for the FRT subjects, with no other significant voice quality findings.ConclusionsVFE and FRT therapy may improve voice quality of life in some individuals with dysphonia. FRT therapy was noninferior to VFE in improving voice quality of life in this study.

Kinematics of birdsong: functional correlation of cranial movements and acoustic features in sparrows

1993 ◽  
Vol 182 (1) ◽  
pp. 147-171 ◽  
Author(s):  
M. W. Westneat ◽  
J. H. Long ◽  
W. Hoese ◽  
S. Nowicki
Keyword(s):  
Vocal Tract ◽  
Active Role ◽  
Acoustic Properties ◽  
Zonotrichia Albicollis ◽  
Low Frequencies ◽  
Acoustic Frequency ◽  
Mean Frequency ◽  
Singing Behavior ◽  
Resonance Properties ◽  
Melospiza Georgiana

The movements of the head and beak of songbirds may play a functional role in vocal production by influencing the acoustic properties of songs. We investigated this possibility by synchronously measuring the acoustic frequency and amplitude and the kinematics (beak gape and head angle) of singing behavior in the white-throated sparrow (Zonotrichia albicollis) and the swamp sparrow (Melospiza georgiana). These birds are closely related emberizine sparrows, but their songs differ radically in frequency and amplitude structure. We found that the acoustic frequencies of notes in a song have a consistent, positive correlation with beak gape in both species. Beak gape increased significantly with increasing frequency during the first two notes in Z. albicollis song, with a mean frequency for note 1 of 3 kHz corresponding to a gape of 0.4 cm (a 15 degrees gape angle) and a mean frequency for note 2 of 4 kHz corresponding to a gape of 0.7 cm (a 30 degrees gape angle). The relationship between gape and frequency for the upswept third note in Z. albicollis also was significant. In M. georgiana, low frequencies of 3 kHz corresponding to beak gapes of 0.2-0.3 cm (a 10–15 degrees break angle), whereas frequencies of 7–8 kHz were associated with flaring of the beak to over 1 cm (a beak angle greater than 50 degrees). Beak gape and song amplitude are poorly correlated in both species. We conclude that cranial kinematics, particularly beak movements, influence the resonance properties of the vocal tract by varying its physical dimensions and thus play an active role in the production of birdsong.

scholarly journals Aspects of Uncertainty Analysis for Large Nonlinear Computational Models

2010 ◽  
Vol 24-25 ◽  
pp. 25-41 ◽  
Author(s):  
Keith Worden ◽  
W.E. Becker ◽  
Manuela Battipede ◽  
Cecilia Surace
Keyword(s):  
Finite Element ◽  
Monte Carlo ◽  
Computational Models ◽  
Element Model ◽  
Finite Element Models ◽  
Bayesian Algorithm ◽  
Basic Principles ◽  
Structure Interaction ◽  
Output Uncertainty ◽  
Input Uncertainties

This paper concerns the analysis of how uncertainty propagates through large computational models like finite element models. If a model is expensive to run, a Monte Carlo approach based on sampling over the possible model inputs will not be feasible, because the large number of model runs will be prohibitively expensive. Fortunately, an alternative to Monte Carlo is available in the form of the established Bayesian algorithm discussed here; this algorithm can provide information about uncertainty with many less model runs than Monte Carlo requires. The algorithm also provides information regarding sensitivity to the inputs i.e. the extent to which input uncertainties are responsible for output uncertainty. After describing the basic principles of the Bayesian approach, it is illustrated via two case studies: the first concerns a finite element model of a human heart valve and the second, an airship model incorporating fluid structure interaction.

Heat Transfer Implications of Acoustic Resonances in HP Turbine Blade Internal Cooling Channels

2015 ◽  
Author(s):  
C. Selcan ◽  
B. Cukurel ◽  
J. Shashank
Keyword(s):  
Heat Transfer ◽  
Turbine Blade ◽  
Cooling System ◽  
Resonance Condition ◽  
Order Approximation ◽  
Acoustic Resonance ◽  
Mode Shapes ◽  
Internal Cooling ◽  
The Impact ◽  
Standing Sound

In an attempt to investigate the acoustic resonance effect of serpentine passages on internal convection heat transfer, the present work examines a typical high pressure turbine blade internal cooling system, based on the geometry of the NASA E3 engine. In order to identify the associated dominant acoustic characteristics, a numerical FEM simulation (two-step frequency domain analysis) is conducted to solve the Helmholtz equation with and without source terms. Mode shapes of the relevant identified eigenfrequencies (in the 0–20kHz range) are studied with respect to induced standing sound wave patterns and the local node/antinode distributions. It is observed that despite the complexity of engine geometries, as a first order approximation, the predominant resonance behavior can be modeled by a same-ended straight duct. Therefore, capturing the physics observed in a generic geometry, the heat transfer ramifications are experimentally investigated in a scaled wind tunnel facility at a representative resonance condition. Focusing on the straight cooling channel’s longitudinal eigenmode in the presence of an isolated rib element, the impact of standing sound waves on convective heat transfer and aerodynamic losses are demonstrated by liquid crystal thermometry, local static pressure and sound level measurements. The findings indicate a pronounced heat transfer influence in the rib wake separation region, without a higher pressure drop penalty. This highlights the potential of modulating the aero-thermal performance of the system via acoustic resonance mode excitations.

Quantify Resonance Inspection With Finite-Element-Based Modal Analyses

2010 ◽  
Author(s):  
K. Lai ◽  
X. Sun ◽  
C. Dasch
Keyword(s):  
Finite Element ◽  
High Stress ◽  
Mesh Size ◽  
Element Model ◽  
Sensitivity Study ◽  
Production Level ◽  
Mode Shapes ◽  
Resonance Spectroscopy ◽  
Frequency Spectra ◽  
Resonance Frequencies

Resonance inspection uses the natural acoustic resonances of a part to identify anomalous parts. Modern instrumentation can measure the many resonant frequencies rapidly and accurately. Sophisticated sorting algorithms trained on sets of good and anomalous parts can rapidly and reliably inspect and sort parts. This paper aims at using finite-element-based modal analysis to put resonance inspection on a more quantitative basis. A production-level automotive steering knuckle is used as the example part for our study. First, the resonance frequency spectra for the knuckle are measured with two different experimental techniques. Next, scanning laser vibrometry is used to determine the mode shape corresponding to each resonance. The material properties including anisotropy are next measured to high accuracy using resonance spectroscopy on cuboids cut from the part. Then, finite element model (FEM) of the knuckle is generated by meshing the actual part geometry obtained with computed tomography (CT). The resonance frequencies and mode shapes are next predicted with a natural frequency extraction analysis after extensive mesh size sensitivity study. The good comparison between the predicted and the experimentally measured resonance spectra indicate that finite-element-based modal analyses have the potential to be a powerful tool in shortening the training process and improving the accuracy of the resonance inspection process for a complex, production level part. The finite element based analysis can also provide a means to computationally test the sensitivity of the frequencies to various possible defects such as porosity or oxide inclusions especially in the high stress regions that the part will experience in service.

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