Aerodynamics and Lumped-Masses Combined with Delay Lines for Modeling Vertical and Anterior-Posterior Phase Differences in Pathological Vocal Fold Vibration

2019 ◽  
Author(s):  
Carlo Drioli ◽  
Philipp Aichinger
Keyword(s):  
Vocal Fold ◽  
Delay Lines ◽  
Vocal Fold Vibration ◽  
Lumped Masses ◽  
Anterior Posterior ◽  
Phase Differences

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.

Cross-Innervation of the Thyroarytenoid Muscle by a Branch from the External Division of the Superior Laryngeal Nerve

1997 ◽  
Vol 106 (7) ◽  
pp. 594-598 ◽  
Author(s):  
Sina Nasri ◽  
Joel A. Sercarz ◽  
Pouneh Beizai ◽  
Young-Mo Kim ◽  
Ming Ye ◽  
...  
Keyword(s):  
Vocal Fold ◽  
Superior Laryngeal Nerve ◽  
Laryngeal Nerve ◽  
Spasmodic Dysphonia ◽  
Clinical Implications ◽  
Motor Innervation ◽  
Vocal Fold Vibration ◽  
Adductor Spasmodic Dysphonia ◽  
Thyroarytenoid Muscle ◽  
Stimulation Of

The neuroanatomy of the larynx was explored in seven dogs to assess whether there is motor innervation to the thyroarytenoid (TA) muscle from the external division of the superior laryngeal nerve (ExSLN). In 3 animals, such innervation was identified. Electrical stimulation of microelectrodes applied to the ExSLN resulted in contraction of the TA muscle, indicating that this nerve is motor in function. This was confirmed by electromyographic recordings from the TA muscle. Videolaryngostroboscopy revealed improvement in vocal fold vibration following stimulation of the ExSLN compared to without it. Previously, the TA muscle was thought to be innervated solely by the recurrent laryngeal nerve. This additional pathway from the ExSLN to the TA muscle may have important clinical implications in the treatment of neurologic laryngeal disorders such as adductor spasmodic dysphonia.

scholarly journals VOCAL-FOLD VIBRATION AT THE ONSET OF PHONATION

1980 ◽  
Vol 83 (2) ◽  
pp. 201-212
Author(s):  
KATSUTAKE HAYASAKI
Keyword(s):  
Vocal Fold ◽  
Vocal Fold Vibration

Reinke's Edema: Phonatory Mechanisms and Management Strategies

1997 ◽  
Vol 106 (7) ◽  
pp. 533-543 ◽  
Author(s):  
Steven M. Zeitels ◽  
Glenn W. Bunting ◽  
Robert E. Hillman ◽  
Traci Vaughn
Keyword(s):  
Lamina Propria ◽  
Fundamental Frequency ◽  
Vocal Fold ◽  
Management Strategies ◽  
Vocal Folds ◽  
Vocal Fold Vibration ◽  
Reinke’S Edema ◽  
Subglottal Pressure ◽  
Almost All ◽  
Superficial Lamina

Reinke's edema (RE) has been associated typically with smoking and sometimes with vocal abuse, but aspects of the pathophysiology of RE remain unclear. To gain new insights into phonatory mechanisms associated with RE pathophysiology, weused an integrated battery of objective vocal function tests to analyze 20 patients (19 women) who underwent phonomicrosurgical resection. Preoperative stroboscopic examinations demonstrated that the superficial lamina propria is distended primarily on the superior vocal fold surface. Acoustically, these individuals have an abnormally low average speaking fundamental frequency (123 Hz), and they generate abnormally high average subglottal pressures (9.7 cm H20). The presence of elevated aerodynamic driving pressures reflects difficulties in producing vocal fold vibration that are most likely the result of mass loading associated with RE, and possibly vocal hyperfunction. Furthermore, it is hypothesized that in the environment of chronic glottal mucositis secondary to smoking and reflux, the cephalad force on the vocal folds by the subglottal driving pressure contributes to the superior distention of the superficial lamina propria. Surgical reduction of the volume of the superficial lamina propria resulted in a significant elevation in fundamental frequency (154 Hz) and improvement in perturbation measures. In almost all instances, both the clinician and the patient perceived the voice as improved. However, these patients continued to generate elevated subglottal pressure (probably a sign of persistent hyperfunction) that was accompanied by visually observed supraglottal strain despite the normalsized vocal folds. This finding suggests that persistent hyperfunctional vocal behaviors may contribute to postsurgical RE recurrence if therapeutic strategies are not instituted to modify such behavior.

Effects of Voice Therapy as Objectively Evaluated by Digitized Laryngeal Stroboscopic Imaging

2002 ◽  
Vol 111 (10) ◽  
pp. 902-908 ◽  
Author(s):  
Renée Speyer ◽  
Pieter A. Kempen ◽  
George Wieneke ◽  
Willem Kersing ◽  
Elham Ghazi Hosseini ◽  
...  
Keyword(s):  
Vocal Fold ◽  
Vocal Folds ◽  
Lesion Size ◽  
Voice Therapy ◽  
Benign Lesions ◽  
Objective Measurements ◽  
Significant Parameter ◽  
Surface Areas ◽  
Vocal Fold Vibration ◽  
Maximal Opening

Objective measurements derived from digitized laryngeal stroboscopic images were used to demonstrate changes in vocal fold vibration and in the size of benign lesions after 3 months of voice therapy. Forty chronically dysphonic patients were studied. By means of a rigid stroboscope, pretreatment and posttreatment recordings were made of the vocal folds at rest and under stroboscopic light during phonation. From each recording, images of the positions at rest and during vibration at maximal opening and at maximal closure were digitized. The surface areas of any lesions and of the glottal gap were independently measured in the digitized images by 2 experienced laryngologists. Referential distances were determined in order to compensate for discrepancies in magnification in the various recordings. After 3 months of voice therapy, significant improvement in lesion size and degree of maximal closure during vibration could be demonstrated in about 50% of the patients. The degree of maximal opening did not prove to be a significant parameter.

Comments on the Myoelastic - Aerodynamic Theory of Phonation

1980 ◽  
Vol 23 (3) ◽  
pp. 495-510 ◽  
Author(s):  
Ingo R. Titze
Keyword(s):  
Vocal Fold ◽  
Vocal Tract ◽  
Driving Forces ◽  
Vibrational Amplitude ◽  
Subglottal Pressure ◽  
Vertical Displacements ◽  
Vocal Intensity ◽  
Tissue Deformations ◽  
Chest Voice ◽  
Phase Differences

The myoelastic-aerodynamic theory of phonation has been quantified and tested with mathematical models. The models suggest that vocal fold oscillation is produced as a result of asymmetric forcing functions over closing and opening portions of the glottal cycle. For nearly uniform tissue displacements, as in falsetto voice, the asymmetry in the driving forces can result from the inertia of the air moving through the glottis. This inertia can in turn be enhanced or suppressed by supraglottal or subglottal vocal tract coupling. More obvious and pronounced asymmetries in the driving forces are associated with non-uniform vocal fold tissue displacements. These are combinations of normal tissue modes, and can result in vertical and horizontal phase differences along the surfaces, as observed in chest voice. The ranges of oscillation increase among various models as more freedom in the simulated tissue movement is incorporated. Of particular significance in initiating and maintaining oscillation are the vertical motions that facilitate coupling of aerodynamic energy into the tissues and allow tissue deformations under conditions of incompressibility. Vertical displacements also can have a significant effect on vocal tract excitation. Control of fundamental frequency of oscillation (FO) is basically myoelastic, partially as a result of deliberate or reflex adjustments of laryngeal muscles, and partially as a result of nonlinear tissue strain over the vibrational cycle. This places limits on the control of FO by subglottal pressure, and forces such control to be inseparably connected with vibrational amplitude, or less directly, with vocal intensity.

A Continuous-Flow Model for Phonatory Reaction Time

1991 ◽  
Vol 34 (3) ◽  
pp. 517-525 ◽  
Author(s):  
Carole Ferrand ◽  
Gordon W. Blood ◽  
Harvey R. Gilbert
Keyword(s):  
Reaction Time ◽  
Continuous Flow ◽  
Vocal Fold ◽  
Flow Model ◽  
Reaction Time Task ◽  
Central Process ◽  
Brain Potentials ◽  
Time Task ◽  
Vocal Fold Vibration ◽  
Yield Information

The purpose of this study was to validate a proposed continuous-flow model of phonatory reaction time by investigating the temporal order of selected laryngeal and neurophysiological events involved in a phonatory reaction time task. Ten normal speakers participated in a phonatory reaction time task. Laryngeal positioning movements prior to vocal fold closure (laryngeal shift) and onset of vocal fold vibration (acoustic onset) were recorded with an electroglottograph. P300 brain potentials were collected simultaneously, and they served as an index of a central process underlying reaction time. The obtained temporal ordering of laryngeal shift, P300, and acoustic onset supported a continuous-flow model of phonatory reaction time. Use of this model might yield information that is more accurate in explaining physiological function and more precise in describing temporal patterning than the serial model.

Videostrobolaryngoscopy of Mucus Layer during Vocal Fold Vibration in Patients with Laryngeal Tension-Fatigue Syndrome

2002 ◽  
Vol 111 (6) ◽  
pp. 537-541 ◽  
Author(s):  
Tzu-Yu Hsiao ◽  
Chia-Ming Liu ◽  
Kai-Nan Lin
Keyword(s):  
Mechanical Properties ◽  
Vocal Fold ◽  
Rough Surfaces ◽  
Voice Disorders ◽  
Vocal Folds ◽  
Voice Disorder ◽  
Mucus Layer ◽  
Vocal Fold Vibration ◽  
Fatigue Syndrome ◽  
Functional Dysphonia

The mucus layer on the vocal folds was examined by videostrobolaryngoscopy in patients with laryngeal tension-fatigue syndrome, a chronic functional dysphonia due to vocal abuse and misuse. Besides the findings in previous reports (such as abnormal glottal closure, phase or amplitude asymmetry, and the irregular mucosal wave), the vocal folds during vibration had an uneven mucus surface. The occurrence of an uneven mucus layer on vocal folds was significantly greater in subjects with this voice disorder (83% or 250 of 301 patients in this series) than in those without voice disorders (18.5% or 5 of 27). The increase of mucus viscosity, mucus aggregation, and the formation of rough surfaces on the vocal folds alter the mechanical properties that contribute to vibration of the cover of the vocal folds, and thereby worsen the symptoms of dysphonia in patients with laryngeal tension-fatigue syndrome.

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