Parameterization of the glottal area, glottal flow, and vocal fold contact area

1984 ◽  
Vol 75 (2) ◽  
pp. 570-580 ◽  
Author(s):  
Ingo R. Titze
Keyword(s):  
Contact Area ◽  
Vocal Fold ◽  
Glottal Flow

scholarly journals Effect of Subglottic Stenosis on Vocal Fold Vibration and Voice Production Using Fluid–Structure–Acoustics Interaction Simulation

2021 ◽  
Vol 11 (3) ◽  
pp. 1221
Author(s):  
Dariush Bodaghi ◽  
Qian Xue ◽  
Xudong Zheng ◽  
Scott Thomson
Keyword(s):  
Flow Rate ◽  
Vocal Fold ◽  
Flow Resistance ◽  
Signal To Noise Ratio ◽  
Area Ratio ◽  
Subglottic Stenosis ◽  
Fluid Structure ◽  
Voice Production ◽  
Vocal Fold Vibration ◽  
Glottal Flow

An in-house 3D fluid–structure–acoustic interaction numerical solver was employed to investigate the effect of subglottic stenosis (SGS) on dynamics of glottal flow, vocal fold vibration and acoustics during voice production. The investigation focused on two SGS properties, including severity defined as the percentage of area reduction and location. The results show that SGS affects voice production only when its severity is beyond a threshold, which is at 75% for the glottal flow rate and acoustics, and at 90% for the vocal fold vibrations. Beyond the threshold, the flow rate, vocal fold vibration amplitude and vocal efficiency decrease rapidly with SGS severity, while the skewness quotient, vibration frequency, signal-to-noise ratio and vocal intensity decrease slightly, and the open quotient increases slightly. Changing the location of SGS shows no effect on the dynamics. Further analysis reveals that the effect of SGS on the dynamics is primarily due to its effect on the flow resistance in the entire airway, which is found to be related to the area ratio of glottis to SGS. Below the SGS severity of 75%, which corresponds to an area ratio of glottis to SGS of 0.1, changing the SGS severity only causes very small changes in the area ratio; therefore, its effect on the flow resistance and dynamics is very small. Beyond the SGS severity of 75%, increasing the SGS severity, leads to rapid increases of the area ratio, resulting in rapid changes in the flow resistance and dynamics.

Monitoring Vocal Fold Abduction through Vocal Fold Contact Area

1988 ◽  
Vol 31 (3) ◽  
pp. 338-351 ◽  
Author(s):  
Martin Rothenberg ◽  
James J. Mahshie
Keyword(s):  
Contact Area ◽  
Time Variation ◽  
Vocal Fold ◽  
Thyroid Cartilage ◽  
Electrical Conductance ◽  
Vocal Folds ◽  
Linear Phase ◽  
Voice Production ◽  
Voiced Speech ◽  
High Pass

A number of commercial devices for measuring the transverse electrical conductance of the thyroid cartilage produce waveforms that can be useful for monitoring movements within the larynx during voice production, especially movements that are closely related to the time-variation of the contact between the vocal folds as they vibrate. This paper compares the various approaches that can be used to apply such a device, usually referred to as an electroglottograph, to the problem of monitoring the time-variation of vocal fold abduction and adduction during voiced speech. One method, in which a measure of relative vocal fold abduction is derived from the duty cycle of the linear-phase high pass filtered electroglottograph waveform, is developed in detail.

scholarly journals Effect of vocal fold asymmetries on glottal flow

2016 ◽  
Vol 126 (11) ◽  
pp. 2534-2538 ◽  
Author(s):  
Liran Oren ◽  
Sid Khosla ◽  
Ephraim Gutmark
Keyword(s):  
Vocal Fold ◽  
Glottal Flow

scholarly journals A model for vocal fold vibratory motion, contact area, and the electroglottogram

1986 ◽  
Vol 80 (5) ◽  
pp. 1309-1320 ◽  
Author(s):  
D. G. Childers ◽  
D. M. Hicks ◽  
G. P. Moore ◽  
Y. A. Alsaka
Keyword(s):  
Contact Area ◽  
Vocal Fold ◽  
Vibratory Motion

scholarly journals Relationship Between the Electroglottographic Signal and Vocal Fold Contact Area

2016 ◽  
Vol 30 (2) ◽  
pp. 161-171 ◽  
Author(s):  
Vít Hampala ◽  
Maxime Garcia ◽  
Jan G. Švec ◽  
Ronald C. Scherer ◽  
Christian T. Herbst
Keyword(s):  
Contact Area ◽  
Vocal Fold

Design of Apparatus for Studying Aerodynamics of Voice Production

2004 ◽  
Author(s):  
Michael Barry
Keyword(s):  
Flow Visualization ◽  
Vocal Fold ◽  
Sound Production ◽  
Vocal Tract ◽  
Vocal Folds ◽  
Flow Speed ◽  
Working Fluid ◽  
Voice Production ◽  
Experimental Apparatus ◽  
Glottal Flow

The design and testing of an experimental apparatus for in vitro study of phonatory aerodynamics (voice production) in humans is presented. The presentation includes not only the details of apparatus design, but flow visualization and Digital Particle Image Velocimetry (DPIV) measurements of the developing flow that occurs during the opening of the constriction from complete closure. The main features of the phonation process have long been understood. A proper combination of air flow from the lungs and of vocal fold tension initiates a vibration of the vocal folds, which in turn valves the airflow. The resulting periodic acceleration of the airstream through the glottis excites the acoustic modes of the vocal tract. It is further understood that the pressure gradient driving glottal flow is related to flow separation on the downstream side of the vocal folds. However, the details of this process and how it may contribute to effects such as aperiodicity of the voice and energy losses in voiced sound production are still not fully grasped. The experimental apparatus described in this paper is designed to address these issues. The apparatus itself consists of a scaled-up duct in which water flows through a constriction whose width is modulated by motion of the duct wall in a manner mimicking vocal fold vibration. Scaling the duct up 10 times and using water as the working fluid allows temporally and spatially resolved measurements of the dynamically similar flow velocity field using DPIV at video standard framing rates (15Hz). Dynamic similarity is ensured by matching the Reynolds number (based on glottal flow speed and glottis width) of 8000, and by varying the Strouhal number (based on vocal fold length, glottal flow speed, and a time scale characterizing the motion of the vocal folds) ranging from 0.01 to 0.1. The walls of the 28 cm × 28 cm test section and the vocal fold pieces are made of clear cast acrylic to allow optical access. The vocal fold pieces are 12.7 cm × 14 cm × 28 cm and are rectangular in shape, except for the surfaces which form the glottis, which are 6.35 cm radius half-circles. Dye injection slots are placed on the upstream side of both vocal field pieces to allow flow visualization. Prescribed motion of the vocal folds is provided by two linear stages. Linear bearings ensure smooth execution of the motion prescribed using a computer interface. Measurements described here use the Laser-Induced Fluorescence (LIF) flow visualization and DPIV techniques and are performed for two Strouhal numbers to assess the effect of opening time on the development of the glottal jet. These measurements are conducted on a plane oriented perpendicular to the glottis, at the duct midplane. LIF measurements use a 5W Argon ion laser to produce a light sheet, which illuminates the dye injected through a slot in each vocal fold piece. Two dye colors are used, one for each side. Quantitative information about the velocity and vorticity fields are obtained through DPIV measurements at the same location as the LIF measurements.

Measuring contact area in synthetic vocal fold replicas using electrical resistance

2016 ◽  
Vol 139 (4) ◽  
pp. 2221-2221
Author(s):  
Kyle L. Syndergaard ◽  
Stephen Warner ◽  
Shelby Dushku ◽  
Scott L. Thomson
Keyword(s):  
Contact Area ◽  
Electrical Resistance ◽  
Vocal Fold

scholarly journals Finite-element modeling of vocal fold self-oscillations in interaction with vocal tract: Comparison of incompressible and compressible flow model

2021 ◽  
Vol 15 (2) ◽  
Author(s):  
Petr Hájek ◽  
Pavel Švancara ◽  
Jaromír Horáček ◽  
Jan G. Švec
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Vocal Fold ◽  
Vocal Tract ◽  
Stokes Equations ◽  
Magnetic Resonance Images ◽  
Coupling Scheme ◽  
Arbitrary Lagrangian Eulerian ◽  
Element Modeling ◽  
Glottal Flow

Finite-element modeling of self-sustained vocal fold oscillations during voice production has mostly considered the air as incompressible, due to numerical complexity. This study overcomes this limitation and studies the influence of air compressibility on phonatory pressures, flow and vocal fold vibratory characteristics. A two-dimensional finite-element model is used, which incorporates layered vocal fold structure, vocal fold collisions, large deformations of the vocal fold tissue, morphing the fluid mesh according to the vocal fold motion by the arbitrary Lagrangian-Eulerian approach and vocal tract model of Czech vowel [i:] based on data from magnetic resonance images. Unsteady viscous compressible or incompressible airflow is described by the Navier-Stokes equations. An explicit coupling scheme with separated solvers for structure and fluid domain was used for modeling the fluid-structure-acoustic interaction. Results of the simulations show clear differences in the glottal flow and vocal fold vibration waveforms between the incompressible and compressible fluid flow. These results provide the evidence on the existence of the coupling between the vocal tract acoustics and the glottal flow (Level 1 interactions), as well as between the vocal tract acoustics and the vocal fold vibrations (Level 2 interactions).

Computational Modeling of Voice Production Using Excised Canine Larynx

2021 ◽  
Author(s):  
Weili Jiang ◽  
Charles Farbos De Luzan ◽  
Xiaojian Wang ◽  
Liran Oren ◽  
Sid Khosla ◽  
...  
Keyword(s):  
Vocal Fold ◽  
Stokes Equations ◽  
Element Model ◽  
Numerical Work ◽  
Continuous Increase ◽  
Voice Production ◽  
Flow Recirculation ◽  
Flow Swirl ◽  
Glottal Flow ◽  
Divergent Angle

Abstract A combined experimental-numerical work was conducted to comprehensively validate a subject-specific continuum model of voice production in larynx using excised canine laryngeal experiments. The computational model is a coupling of the Navier-Stokes equations for glottal flow dynamics and a finite element model of vocal fold dynamics. The numerical simulations employed a cover-body vocal fold structure with the geometry reconstructed from MRI scans and the material properties determined through an optimization-based inverse process of experimental indentation measurement. The results showed that the simulations predicted key features of the dynamics observed in the experiments, including the skewing of the glottal flow waveform, mucosal wave propagation, continuous increase of the divergent angle and intraglottal swirl strength during glottal closing, and flow recirculation between glottal jet and vocal fold. The simulations also predicted the increase of the divergent angle, glottal jet speed and intraglottal flow swirl strength with the subglottal pressure, same as in the experiments. Quantitatively, the simulations over-predicted the frequency and jet speed and under-predicted the flow rate and divergent angle for the larynx under study. The limitations of the model and their implications were discussed.

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