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The Journal of the Acoustical Society... May 2023With age, the atrophy of the thyroarytenoid muscle (TAM), and thus atrophy of the vocal folds, leads to decreased glottal closure, increased breathiness, and a loss in...
With age, the atrophy of the thyroarytenoid muscle (TAM), and thus atrophy of the vocal folds, leads to decreased glottal closure, increased breathiness, and a loss in voice quality, which results in a reduced quality of life. A method to counteract the atrophy of the TAM is to induce hypertrophy in the muscle by functional electric stimulation (FES). In this study, phonation experiments were performed with ex vivo larynges of six stimulated and six unstimulated ten-year-old sheep to investigate the impact of FES on phonation. Electrodes were implanted bilaterally near the cricothyroid joint. FES treatment was provided for nine weeks before harvesting. The multimodal measurement setup simultaneously recorded high-speed video of the vocal fold oscillation, the supraglottal acoustic signal, and the subglottal pressure signal. Results of 683 measurements show a 65.6% lower glottal gap index, a 22.7% higher tissue flexibility (measured by the amplitude to length ratio), and a 473.7% higher coefficient of determination (R2) of the regression of subglottal and supraglottal cepstral peak prominence during phonation for the stimulated group. These results suggest that FES improves the phonatory process for aged larynges or presbyphonia.
Topics: Sheep; Animals; Quality of Life; Vocal Cords; Phonation; Laryngeal Muscles; Electric Stimulation
PubMed: 37154554
DOI: 10.1121/10.0017923 -
The Annals of Otology, Rhinology, and... Jan 2009We describe a method for eliciting phonation in an in vivo rabbit preparation using low-frequency, bipolar pulsed stimulation of the cricothyroid muscles with airflow...
OBJECTIVES
We describe a method for eliciting phonation in an in vivo rabbit preparation using low-frequency, bipolar pulsed stimulation of the cricothyroid muscles with airflow delivered to the glottis.
METHODS
Ten New Zealand White breeder rabbits weighing 3 to 5 kg were used in this study. The cricothyroid muscles were isolated bilaterally, and separate pairs of anode-cathode hooked-wire electrodes were inserted into each muscle. A Grass S-88 stimulator and 2 constant-current PSIU6 isolation units were used to deliver bipolar square wave pulses to each cricothyroid muscle, with airflow delivered to the glottis through a cuffed endotracheal tube.
RESULTS
Phonation was evoked with a 50-Hz, 4-mA stimulus train of 1-ms pulses delivered to each cricothyroid muscle. The pulse trains were on for 2 seconds and were repeated every 5 seconds over a period of 180 minutes. Airflow was delivered at 143 cm3/s, producing phonation measuring 71 to 85 dB sound pressure level.
CONCLUSIONS
Evoked phonation is feasible in rabbits by use of bipolar stimulation of the cricothyroid muscles with airflow delivered to the glottis. The in vivo rabbit preparation described may provide a useful small animal option for studies of evoked phonation. From the level and consistency of the adduction observed, we hypothesize that current spreading to the underlying adductor muscles and nerves resulted in neural pathway involvement beyond discrete activation of the cricothyroid muscle, providing sufficient approximation of the vocal folds for phonation.
Topics: Animals; Cricoid Cartilage; Endoscopy; Glottis; Larynx; Phonation; Rabbits; Thyroid Gland; Time Factors
PubMed: 19244964
DOI: 10.1177/000348940911800109 -
Journal of Speech, Language, and... Apr 2006Maximum flow declination rate (MFDR) in the glottis is known to correlate strongly with vocal intensity in voicing. This declination, or negative slope on the glottal... (Review)
Review
PURPOSE
Maximum flow declination rate (MFDR) in the glottis is known to correlate strongly with vocal intensity in voicing. This declination, or negative slope on the glottal airflow waveform, is in part attributable to the maximum area declination rate (MADR) and in part to the overall inertia of the air column of the vocal tract (lungs to lips). The purpose of this theoretical study was to show the possible contributions of air inertance and MADR to MFDR.
METHOD
A simplified computational model of the kinematics of vocal fold movement was utilized to compute a glottal area function. The glottal flow was computed interactively with lumped vocal tract parameters in the form of resistance and inertive reactance.
RESULTS
It was shown that MADR depends almost entirely on the ratio of vibrational amplitudes of the lower to upper margins of the vocal fold tissue. Adduction, vertical phase difference, and prephonatory convergence of the glottis have a lesser effect on MADR. A relatively simple rule was developed that relates MFDR to a vibrational amplitude ratio and vocal tract inertance.
CONCLUSION
It was concluded that speakers and singers have multiple options for control of intensity, some of which involve more source-filter interaction than others.
Topics: Air Pressure; Biomechanical Phenomena; Glottis; Humans; Mathematical Computing; Models, Biological; Phonation; Pulmonary Ventilation
PubMed: 16671855
DOI: 10.1044/1092-4388(2006/034) -
Journal of Voice : Official Journal of... Nov 2011Maximum phonation time (MPT), a clinical measurement of the longest time one can phonate a vowel, typically /a/, is a frequently used measure of vocal function, but...
OBJECTIVES/HYPOTHESIS
Maximum phonation time (MPT), a clinical measurement of the longest time one can phonate a vowel, typically /a/, is a frequently used measure of vocal function, but normative data are lacking for MPT in healthy older adults. The aim of this study was to provide data on MPT in healthy older adults and to determine the effect of advanced age, gender, and repeated measures on MPT.
STUDY DESIGN
Prospective.
METHODS
Sixty-nine healthy older adult volunteers participated (ie, 15, 26, and 28 in the seventh, eighth, and ninth decades of life, respectively). The effects of age, gender, and repeated measures (three trials in a single session) on MPT were assessed. Mean, standard deviation, compound symmetry covariance, analysis of variance, and analysis of covariance were used for statistical analysis.
RESULTS
Neither age group, gender, trial, nor their interactions was statistically significant (P>0.05). Adults in the seventh, eighth, and ninth decades of life had mean MPTs of 22.27 (standard error [SE]=1.56), 22.97 (SE=1.11), and 21.14 (SE=0.97) seconds, respectively. Females and males had mean MPTs of 20.96 (SE=0.92) and 23.23 (SE=0.96) seconds, respectively. Finally, MPTs for trials 1, 2, and 3 were 21.77 (SE=1.09), 21.67 (SE=1.12), and 22.80 (SE=1.27), respectively.
CONCLUSIONS
MPTs were longer in this group of older adults than previously reported and did not vary significantly with age or gender. Additionally, across a single short sampling session, measurements were relatively stable across three trials of MPTs.
Topics: Aged; Aged, 80 and over; Aging; Female; Humans; Male; Phonation; Sex Factors; Time Factors
PubMed: 21439778
DOI: 10.1016/j.jvoice.2010.10.002 -
The Journal of the Acoustical Society... May 1995The vocal fold mucosa, which consists of the epithelium and the superficial layer of the lamina propria, has been modeled by a fluid encapsulated in a silicone membrane....
The vocal fold mucosa, which consists of the epithelium and the superficial layer of the lamina propria, has been modeled by a fluid encapsulated in a silicone membrane. The artificial mucosa was attached to a rigid (metal) vocal fold body and introduced into an airflow channel, creating a rectangular glottis. Flow-induced oscillation of the mucosa was achieved at various subglottal pressures and glottal diameters. Phonation threshold pressure, the parameter of interest, was lowest (on the order of 0.4 kPa) for glottal diameters between 0.0 and 0.1 mm and for fluids with the lowest viscosity. There was a consistent hysteresis effect; that is, phonation threshold pressure was always lower for oscillation offset than onset.
Topics: Auditory Threshold; Epithelium; Humans; Phonation; Pulmonary Ventilation; Vocal Cords
PubMed: 7759648
DOI: 10.1121/1.411870 -
International Journal of Language &... May 2023A promising way to obtain vocal economy and efficiency is by semi-occluding the vocal tract while phonating. Current knowledge about the immediate effects of...
Immediate effects of straw phonation in air or water on the laryngeal function and configuration of female speech-language pathology students visualised with strobovideolaryngoscopy: A randomised controlled trial.
BACKGROUND
A promising way to obtain vocal economy and efficiency is by semi-occluding the vocal tract while phonating. Current knowledge about the immediate effects of semi-occluded vocal tract (SOVT) phonation on the laryngeal function and configuration is based mainly on computer modelling or excised larynges studies. In in vivo SOVT studies, electroglottography (EGG) has been the most commonly used laryngeal outcome, showing contradictory results between studies. Therefore, exploring these aspects by direct visualisation of the human larynx during SOVT phonation using strobovideolaryngoscopy (SVL) is needed.
AIMS
The aim of this study was to investigate and compare the immediate effects of straw phonation (SP) in air, SP in 2 cm water, and SP in 5 cm water (with stirring straws), on the laryngeal function and configuration of a homogeneous group of vocally healthy female speech-language pathology students, visualised with flexible SVL.
METHODS & PROCEDURE
A randomised controlled trial was used. Fifty-two female speech-language pathology students (mean age: 18.7 years, SD: 0.6) were assigned randomly to one of three experimental groups or a control group: (1) SP in air, (2) SP in 2 cm water, (3) SP in 5 cm water or (4) [u] phonation with similar soft onset and slightly pursed lips as in SP but without a straw (control group). The participants underwent flexible SVL during habitual [u] phonation, followed by the specific SOVT exercise of their group assignment. All video samples were evaluated randomly and blindly by two experienced investigators using the Voice-Vibratory Assessment with Laryngeal Imaging (VALI) rating form, first independently and then by consensus.
OUTCOME & RESULTS
Compared to habitual phonation, the vibrational amplitude decreased during SP in 5 cm water and SP in 2 cm water, being more prominent in the first, more flow-resistant exercise. The mucosal wave also decreased during SP in 5 cm water. The anteroposterior (AP) supraglottic compression similarly increased during SP in air, SP in 2 cm water, and SP in 5 cm water. Further, a rise in mediolateral (ML) compression and a decrease in phase symmetry and regularity were found during SP in 2 cm water. A similar decrease in regularity was observed during SP in 5 cm water.
CONCLUSIONS & IMPLICATIONS
Both SP in air and SP in water cause positive immediate laryngeal effects for voice training opportunities. More AP supraglottic activity found during each SP exercise might indicate epilarynx narrowing, an economic phenomenon associated with SOVT. Immersing the straw in water additionally diminished the vibrational amplitude, lowering vocal fold impact stress and risk for phonotrauma during the exercise. The decreased regularity of the vibrational cycles during SP in water might be due to the varying back pressure created by the water bubbling. The impact of SP in water on ML supraglottic compression needs further investigation.
WHAT THIS PAPER ADDS
What is already known on the subject A promising way to obtain vocal economy and efficiency is by semi-occluding the vocal tract while phonating. Current knowledge about the immediate effects of semi-occluded vocal tract (SOVT) phonation on the laryngeal function and configuration is based mainly on computer modelling or excised larynges studies. In in vivo SOVT studies, electroglottography (EGG) has been the most commonly used laryngeal outcome, showing contradictory results between studies. Therefore, exploring these aspects by direct visualisation of the human larynx during SOVT phonation using strobovideolaryngoscopy (SVL) is needed. What this paper adds to existing knowledge Group results of the current study generally support earlier computer modelling and in vivo studies, strengthening the current SOVT knowledge. Both SP in air and SP in water cause positive immediate laryngeal effects for voice training opportunities. More anteroposterior (AP) supraglottic activity found during each SP exercise might indicate epilarynx narrowing, an economic phenomenon associated with SOVT. Immersing the straw in water additionally diminished the vibrational amplitude, lowering vocal fold impact stress and risk for phonotrauma during the exercise. The decreased regularity of the vibrational cycles during SP in water might be due to the varying back pressure created by the water bubbling. The impact of SP in water on ML supraglottic compression needs further investigation. What are the potential or actual clinical implications of this work? Current results support that both SP in air and SP in water can be useful exercises in voice training. SP in water has shown the additional gain of lowering the vibrational amplitude during the exercise, hence supporting its appropriateness for vocal warm-ups by minimising vocal fold impact stress and the risk of phonotrauma. In the future, large-scale randomised controlled trials in other subgroups of voice users, including dysphonic patients, are needed to support evidence-based practice. SVL can facilitate the search for individualised training and therapy approaches.
Topics: Humans; Female; Adolescent; Speech-Language Pathology; Voice Quality; Phonation; Larynx; Voice Training; Students; Randomized Controlled Trials as Topic
PubMed: 36722126
DOI: 10.1111/1460-6984.12838 -
Annals of Internal Medicine Nov 2020
Topics: Humans; Phonation; Respiration; Respiratory Insufficiency
PubMed: 32584592
DOI: 10.7326/M20-4186 -
The Laryngoscope Dec 2009The present study proposed to estimate phonation threshold pressure (PTP) noninvasively using airflow redirection into a pneumatic capacitance system. (Comparative Study)
Comparative Study
OBJECTIVES/HYPOTHESIS
The present study proposed to estimate phonation threshold pressure (PTP) noninvasively using airflow redirection into a pneumatic capacitance system.
STUDY DESIGN
Prospective study.
METHODS
Subjects phonated into the device, which interrupts airflow mechanically and redirects the flow into a pneumatic capacitor. Five interruptions were effected per trial. PTP was estimated as the difference between subglottal pressure (SGP) and transglottal pressure at phonation offset. The novel method was tested for consistency in 20 normal human subjects at low (75 dB) and high (85 dB) sound pressure levels. The device was tested for validity on a tracheotomy patient.
RESULTS
Mean SGP was 9.02 +/- 3.27 cm H(2)O, and mean PTP was 3.68 +/- 1.41 cm H(2)O. Intrasubject coefficient of variation, a measure of intrasubject consistency, was 0.33 +/- 0.23. Statistically significant differences existed between the means of SGP but not PTP at 75 dB and 85 dB. The correlation coefficient between accepted and experimental SGP in a tracheotomy patient was 0.947 (P < .001).
CONCLUSIONS
Measurements corresponded well to previously reported values, and intrasubject variability was low, indicating the device was consistent. Testing on a tracheotomy patient demonstrated validity. More research is needed to determine the sensitivity and specificity of the device in differentiating between normal and pathological voices. This device may have clinical application as a noninvasive and reliable method of estimating PTP and indicating that laryngeal health is likely abnormal.
Topics: Adolescent; Adult; Electrodiagnosis; Humans; Larynx; Phonation; Pressure; Prospective Studies; Speech Production Measurement; Tracheotomy; Velopharyngeal Insufficiency; Young Adult
PubMed: 19688842
DOI: 10.1002/lary.20611 -
The Journal of the Acoustical Society... Jul 1998Phonation onset is discussed in the framework of dynamical systems as a Hopf bifurcation, i.e., as a transition from damped to sustained vocal fold oscillations due to...
Phonation onset is discussed in the framework of dynamical systems as a Hopf bifurcation, i.e., as a transition from damped to sustained vocal fold oscillations due to changes of parameters defining the underlying laryngeal configuration (e.g., adduction, subglottal pressure, muscular activity). An analytic envelope curve of the oscillation onset is deduced by analyzing the Hopf bifurcation in mathematical models of the vocal folds. It is governed by a single time constant which can be identified with the physiological parameter phonation onset time. This parameter reflects the laryngeal state prior to phonation and can be used as a quantitative classification criterion in order to assess the phonation onset in clinical diagnosis. The extraction of the phonation onset time from simulated time series using a simplified two-mass model and from digital high-speed videos is described in detail. It shows a good agreement between theory and measurement.
Topics: Electric Stimulation; Humans; Models, Biological; Phonation; Time Factors; Vocal Cords
PubMed: 9670538
DOI: 10.1121/1.423250 -
Journal of Communication Disorders 2023The purpose of the study was to investigate the effects of flow phonation voice therapy on laryngeal physiology and vocal quality in persons with primary Muscle Tension... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVE
The purpose of the study was to investigate the effects of flow phonation voice therapy on laryngeal physiology and vocal quality in persons with primary Muscle Tension Dysphonia (MTD1).
METHODS
Seventeen participants with a diagnosis of MTD1 completed the study. Participants were randomized to two groups. Group 1 (9 participants) received flow phonation treatment and individualized vocal hygiene education for 12 sessions over six weeks. Group 2 (8 participants) received vocal hygiene education only for three weeks (6 sessions), followed by another three weeks (6 sessions) of both vocal hygiene instruction and flow phonation therapy. Treatment consisted of cup-bubble blowing, gargling, and stretch and flow exercises. Visual-perceptual. auditory-perceptual, acoustic, aerodynamic and voice-related quality-of-life measures were obtained at three time points: before treatment, three weeks after initiation of treatment and after completion of treatment.
RESULTS
Voice quality was perceived to be significantly improved in both groups. Voice related quality-of-life trended toward improvement for both groups across time points. Changes in aerodynamic and acoustic measures did not reach statistical significance compared to baseline for both groups. Visual comparisons of laryngeal closure patterns demonstrated comparably better outcomes for Group 1.
CONCLUSIONS
Results of this study indicate flow phonation exercises can potentially be favorably employed for individuals with MTD1. In particular, it appears that the exercises aid in alleviating vocal hyperfunction, as evidenced by visual perceptual stroboscopic analysis, and clinically improved auditory-perceptual measures.
Topics: Humans; Dysphonia; Muscle Tonus; Voice Training; Treatment Outcome; Phonation
PubMed: 36502668
DOI: 10.1016/j.jcomdis.2022.106290