Using Semi-Occluded Vocal Tract Exercises in Voice Therapy: The Clinician's Primer

2014 ◽  
Vol 24 (2) ◽  
pp. 71-79 ◽  
Author(s):  
Marci D. Rosenberg
Keyword(s):  
Vocal Fold ◽  
Vocal Tract ◽  
Voice Therapy ◽  
Exact Nature ◽  
Voice Production ◽  
Vocal Fold Vibration

Semi-occluded vocal tract (SOVT) exercises have long been used by voice trainers and pedagogues and have been particularly popular in Scandinavia dating as far back as the 1800s. Titze (1988, 1994, 2006; Titze, Riede, & Popolo, 2008; Titze & Verdolini-Abbot, 2012) has contributed significantly to the exploration of the SOVT and impact on voice production, and these types of exercise have become ubiquitous in the clinical voice arena. Although SOVT exercises are commonly used, there continue to be questions about the exact nature of how they impact phonation and improved vocal economy. This article aims to explore the physiology of a SOVT on vocal fold vibration and vocal output. Several variations are described within context of recent research.

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.

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.

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.

Phonetics of Singing in Western Classical Style

2018 ◽  
Author(s):  
Johan Sundberg
Keyword(s):  
Fundamental Frequency ◽  
Vocal Fold ◽  
Vocal Tract ◽  
Formant Frequency ◽  
Vowel Identification ◽  
Fundamental Frequencies ◽  
Vocal Fold Vibration ◽  
Syllable Duration ◽  
Classical Singing ◽  
The Voice

The function of the voice organ is basically the same in classical singing as in speech. However, loud orchestral accompaniment has necessitated the use of the voice in an economical way. As a consequence, the vowel sounds tend to deviate considerably from those in speech. Male voices cluster formant three, four, and five, so that a marked peak is produced in spectrum envelope near 3,000 Hz. This helps them to get heard through a loud orchestral accompaniment. They seem to achieve this effect by widening the lower pharynx, which makes the vowels more centralized than in speech. Singers often sing at fundamental frequencies higher than the normal first formant frequency of the vowel in the lyrics. In such cases they raise the first formant frequency so that it gets somewhat higher than the fundamental frequency. This is achieved by reducing the degree of vocal tract constriction or by widening the lip and jaw openings, constricting the vocal tract in the pharyngeal end and widening it in the mouth. These deviations from speech cause difficulties in vowel identification, particularly at high fundamental frequencies. Actually, vowel identification is almost impossible above 700 Hz (pitch F5). Another great difference between vocal sound produced in speech and the classical singing tradition concerns female voices, which need to reduce the timbral differences between voice registers. Females normally speak in modal or chest register, and the transition to falsetto tends to happen somewhere above 350 Hz. The great timbral differences between these registers are avoided by establishing control over the register function, that is, over the vocal fold vibration characteristics, so that seamless transitions are achieved. In many other respects, there are more or less close similarities between speech and singing. Thus, marking phrase structure, emphasizing important events, and emotional coloring are common principles, which may make vocal artists deviate considerably from the score’s nominal description of fundamental frequency and syllable duration.

Phonetics of Vowels

2019 ◽  
Author(s):  
Christine Ericsdotter Nordgren
Keyword(s):  
Vocal Fold ◽  
Vocal Tract ◽  
Point Of View ◽  
Vowel Quality ◽  
Language Experience ◽  
Upper Airways ◽  
Vocal Fold Vibration ◽  
General Linguistic ◽  
Vocal Tract Shape

Speech sounds are commonly divided into two main categories in human languages: vowels, such as ‘e’, ‘a’, ‘o’, and consonants, such as ‘k’, ‘n’, ‘s’. This division is made on the basis of both phonetic and phonological principles, which is useful from a general linguistic point of view but problematic for detailed description and analysis. The main differences between vowels and consonants are that (1) vowels are sounds produced with an open airway between the larynx and the lips, at least along the midline, whereas consonants are produced with a stricture or closure somewhere along it; and (2) that vowels tend to be syllabic in languages, meaning that they embody a sonorous peak in a syllable, whereas only some kinds of consonants tend to be syllabic. There are two main physical components needed to produce a vowel: a sound source, typically a tone produced by vocal fold vibration at the larynx, and a resonator, typically the upper airways. When the tone resonates in the upper airways, it gets a specific quality of sound, perceived and interpreted as a vowel quality, for example, ‘e’ or ‘a’. Which vowel quality is produced is determined by the shape of the inner space of the throat and mouth, the vocal tract shape, created by the speaker’s configuration of the articulators, which include the lips, tongue, jaw, hard and soft palate, pharynx, and larynx. Which vowel is perceived is determined by the auditory and visual input as well as by the listener’s expectations and language experience. Diachronic and synchronic studies on vowel typology show main trends in the vowel inventories in the worlds’ languages, which can be associated with human phonetic aptitude.

scholarly journals A Fast Semiautomatic Algorithm for Centerline-Based Vocal Tract Segmentation

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Anton A. Poznyakovskiy ◽  
Alexander Mainka ◽  
Ivan Platzek ◽  
Dirk Mürbe
Keyword(s):  
Major Part ◽  
Vocal Tract ◽  
Active Contours ◽  
Three Dimensional ◽  
Voice Therapy ◽  
Segmentation Method ◽  
Voice Production ◽  
Medical Issues ◽  
Dimensional Measurements ◽  
Spatial Geometry

Vocal tract morphology is an important factor in voice production. Its analysis has potential implications for educational matters as well as medical issues like voice therapy. The knowledge of the complex adjustments in the spatial geometry of the vocal tract during phonation is still limited. For a major part, this is due to difficulties in acquiring geometry data of the vocal tract in the process of voice production. In this study, a centerline-based segmentation method using active contours was introduced to extract the geometry data of the vocal tract obtained with MRI during sustained vowel phonation. The applied semiautomatic algorithm was found to be time- and interaction-efficient and allowed performing various three-dimensional measurements on the resulting model. The method is suitable for an improved detailed analysis of the vocal tract morphology during speech or singing which might give some insights into the underlying mechanical processes.

scholarly journals Vocal Fold Vibration Characteristics during SOVTE using a Vibration Simulator and Digital Kymography

2021 ◽  
Vol 26 (4) ◽  
pp. 921-932
Author(s):  
Ji Sung Kim ◽  
Seong Hee Choi ◽  
Kyoungjae Lee ◽  
Chul-Hee Choi ◽  
Soo-Geun Wang ◽  
...  
Keyword(s):  
Clinical Practice ◽  
Vocal Fold ◽  
Clinical Evidence ◽  
Vocal Tract ◽  
Voice Quality ◽  
Vibration Characteristics ◽  
Single Source ◽  
Vocal Fold Vibration ◽  
Vibration Parameters

Objectives: The purpose of this study is to investigate the characteristics of vocal fold vibration during sustained vowel /a/ phonation and various semi-occluded vocal tract exercise (SOVTEs) using a vibration simulator and digital kymography (DKG).Methods: A total of 12 normal young speakers (6 males, 6 females) aged 20-30 years participated in the study. They phonated a sustained /a/ vowel and performed SOVTE. The vocal fold vibration characteristics were measured according to the number of vibration sources (single vs. double), and vocal tract occlusion degree using a vibration simulator and DKG. Glottal gap quotient (GQ, %), speed quotient (SQ, %) and amplitude (pixel) were estimated quantitatively from the DKG image.Results: The results showed that significantly higher GQ (p = .000) and SQ (p = .000) were observed in the humming and bilabial fricative /β/ compared to open vowels. The amplitude was significantly higher in the open vowel /a/ than in humming (p = .018) and bilabial fricative /β/ (p = .003). Also, when comparing the vocal fold vibration parameters according to vibration type (single source: straw phonation vs. double source: straw phonation with water), the double source presented a significantly higher GQ (p = .000) as well as SQ (p = .008) in comparison with a single source.Conclusion: SOVTE showed a glottal gap that is different from the opened vowel /a/. It also had a longer opening of the vocal fold and a smaller amplitude than the vowel. This suggests that SOVTE may be helpful for facilitating vocal fold vibration and good voice quality in clinical practice. The current study can be meaningful in providing theoretical and clinical evidence for SOVTE.

Simulation of the coupling between vocal-fold vibration and time-varying vocal tract

2011 ◽  
Vol 130 (4) ◽  
pp. 2441-2441
Author(s):  
Yosuke Tanabe ◽  
Parham Mokhtari ◽  
Hironori Takemoto ◽  
Tatsuya Kitamura
Keyword(s):  
Vocal Fold ◽  
Vocal Tract ◽  
Time Varying ◽  
Vocal Fold Vibration

Biomechanical Effects of Hydration in Vocal Fold Tissues

2002 ◽  
Vol 126 (5) ◽  
pp. 528-537 ◽  
Author(s):  
Roger W. Chan ◽  
Niro Tayama
Keyword(s):  
Shear Modulus ◽  
Viscoelastic Properties ◽  
Vocal Fold ◽  
Damping Ratio ◽  
Empirical Support ◽  
Tissue Stiffness ◽  
Voice Production ◽  
Vocal Fold Vibration ◽  
Elastic Shear

OBJECTIVE: It has often been hypothesized, with little empirical support, that vocal fold hydration affects voice production by mediating changes in vocal fold tissue rheology. To test this hypothesis, we attempted in this study to quantify the effects of hydration on the viscoelastic shear properties of vocal fold tissues in vitro. STUDY DESIGN: Osmotic changes in hydration (dehydration and rehydration) of 5 excised canine larynges were induced by sequential incubation of the tissues in isotonic, hypertonic, and hypotonic solutions. Elastic shear modulus ( G'), dynamic viscosity η' and the damping ratio ζ of the vocal fold mucosa (lamina propria) were measured as a function of frequency (0.01 to 15 Hz) with a torsional rheometer. RESULTS: Vocal fold tissue stiffness (G') and viscosity increased significantly (by 4 to 7 times) with the osmotically induced dehydration, whereas they decreased by 22% to 38% on the induced rehydration. Damping ratio (ζ) also increased with dehydration and decreased with rehydration, but the detected differences were not statistically significant at all frequencies. CONCLUSION: These findings support the longstanding hypothesis that hydration affects vocal fold vibration by altering tissue rheologic (or viscoelastic) properties. SIGNIFICANCE: Our results demonstrated the biomechanical importance of hydration in vocal fold tissues and suggested that hydration approaches may potentially improve the biomechanics of phonation in vocal fold lesions involving disordered fluid balance.

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