scholarly journals Influence of vocal fold cover layer thickness on its vibratory dynamics during voice production

2019 ◽  
Vol 146 (1) ◽  
pp. 369-380 ◽  
Author(s):  
Weili Jiang ◽  
Xudong Zheng ◽  
Qian Xue
Keyword(s):  
Layer Thickness ◽  
Vocal Fold ◽  
Voice Production ◽  
Cover Layer ◽  
Fold Cover

In vivo vocal fold cover layer replacement

2014 ◽  
Vol 125 (2) ◽  
pp. 406-411 ◽  
Author(s):  
Jennifer Long ◽  
Jonathan Salinas ◽  
Sassan Rafizadeh ◽  
Georg Luegmair ◽  
Zhaoyan Zhang ◽  
...  
Keyword(s):  
Vocal Fold ◽  
Cover Layer ◽  
Fold Cover

scholarly journals Effect of Longitudinal Variation of Vocal Fold Inner Layer Thickness on Fluid-Structure Interaction During Voice Production

2018 ◽  
Vol 140 (12) ◽  
Author(s):  
Weili Jiang ◽  
Qian Xue ◽  
Xudong Zheng
Keyword(s):  
Computational Model ◽  
Layer Thickness ◽  
Vibration Amplitude ◽  
Vocal Fold ◽  
Fluid Structure Interaction ◽  
Thickness Variation ◽  
Longitudinal Variation ◽  
Fluid Structure ◽  
Voice Production ◽  
Structure Interaction

A three-dimensional fluid-structure interaction computational model was used to investigate the effect of the longitudinal variation of vocal fold inner layer thickness on voice production. The computational model coupled a finite element method based continuum vocal fold model and a Navier–Stokes equation based incompressible flow model. Four vocal fold models, one with constant layer thickness and the others with different degrees of layer thickness variation in the longitudinal direction, were studied. It was found that the varied thickness resulted in up to 24% stiffness reduction at the middle and up to 47% stiffness increase near the anterior and posterior ends of the vocal fold; however, the average stiffness was not affected. The fluid-structure interaction simulations on the four models showed that the thickness variation did not affect vibration amplitude, glottal flow rate, and the waveform related parameters. However, it increased glottal angles at the middle of the vocal fold, suggesting that vocal fold vibration amplitude was determined by the average stiffness of the vocal fold, while the glottal angle was determined by the local stiffness. The models with longitudinal variation of layer thickness consumed less energy during the vibrations compared with the constant layer thickness one.

Vocal Fold Cover Layer with a Tissue-Engineered Structure Containing Epithelium and Fibroblast of Oral Mucosa

2013 ◽  
Vol 149 (2_suppl) ◽  
pp. P214-P214
Author(s):  
Shunichi Chitose ◽  
Mioko Fukahori ◽  
Shintaro Sueyoshi ◽  
Takashi Kurita ◽  
Kiminori Sato ◽  
...  
Keyword(s):  
Oral Mucosa ◽  
Vocal Fold ◽  
Cover Layer ◽  
Fold Cover

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.

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.

Respiratory and Laryngeal Measures of Children and Women With Bilateral Vocal Fold Nodules

1994 ◽  
Vol 37 (6) ◽  
pp. 1229-1243 ◽  
Author(s):  
Christine M. Sapienza ◽  
Elaine T. Stathopoulos
Keyword(s):  
Lung Volume ◽  
Respiratory Function ◽  
Vocal Fold ◽  
Multidimensional Analysis ◽  
Specific Information ◽  
Laryngeal Function ◽  
Voice Production ◽  
Normal Voice ◽  
Vocal Fold Nodules ◽  
Simultaneous Assessment

Simultaneous assessment of laryngeal and respiratory function was completed on 8 children and 10 women with bilateral vocal fold nodules and compared to that of 8 children and 10 women with normal voice production. Laryngeal function for the individuals with bilateral vocal fold nodules was characterized by significantly higher peak, altemating, and minimum glottal airflow. The presence of the high glottal airflow was accompanied by a significantly larger lung volume excursion. Both the children with nodules and those with normal voice showed laryngeal and respiratory function differences when compared to adults. All subject groups demonstrated appropriate laryngeal and respiratory function when increasing intensity from comfortable to loud speech. Simultaneous measurement of laryngeal and respiratory function using a multidimensional analysis of voice production is advocated in the evaluation of voice disorders because it can provide specific information regarding which of the subsystems of voice production are compromised.

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