Combined simulation of two‐dimensional airflow and vocal‐fold vibration

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.

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

Annals of Otology Rhinology & Laryngology ◽

10.1177/000348949710600712 ◽

1997 ◽

Vol 106 (7) ◽

pp. 594-598 ◽

Cited By ~ 41

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.

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VOCAL-FOLD VIBRATION AT THE ONSET OF PHONATION

Nippon Jibiinkoka Gakkai Kaiho ◽

10.3950/jibiinkoka.83.201 ◽

1980 ◽

Vol 83 (2) ◽

pp. 201-212

Author(s):

KATSUTAKE HAYASAKI

Keyword(s):

Vocal Fold ◽

Vocal Fold Vibration

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Reinke's Edema: Phonatory Mechanisms and Management Strategies

Annals of Otology Rhinology & Laryngology ◽

10.1177/000348949710600701 ◽

1997 ◽

Vol 106 (7) ◽

pp. 533-543 ◽

Cited By ~ 68

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.

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

Annals of Otology Rhinology & Laryngology ◽

10.1177/000348940211101007 ◽

2002 ◽

Vol 111 (10) ◽

pp. 902-908 ◽

Cited By ~ 22

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.

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