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PloS One 2022Investigations of neuromuscular control of voice production have primarily focused on the roles of muscle activation levels, posture, and stiffness at phonation onset....
Investigations of neuromuscular control of voice production have primarily focused on the roles of muscle activation levels, posture, and stiffness at phonation onset. However, little work has been done investigating the stability of the phonation process in regards to spontaneous changes in vibratory mode of vocal fold oscillation as a function of neuromuscular activation. We evaluated 320 phonatory conditions representing combinations of superior and recurrent laryngeal nerve (SLN and RLN) activations in an in vivo canine model of phonation. At each combination of neuromuscular input, airflow was increased linearly to reach phonation onset and beyond from 300 to 1400 mL/s. High-speed video and acoustic data were recorded during phonation, and spectrograms and glottal-area-based parameters were calculated. Vibratory mode changes were detected based on sudden increases or drops of local fundamental frequency. Mode changes occurred only when SLNs were concurrently stimulated and were more frequent for higher, less asymmetric RLN stimulation. A slight increase in amplitude and cycle length perturbation usually preceded the changes in the vibratory mode. However, no inherent differences between signals with mode changes and signals without were found.
Topics: Animals; Dogs; Glottis; Laryngeal Nerves; Larynx; Phonation; Vibration; Vocal Cords
PubMed: 35421159
DOI: 10.1371/journal.pone.0266910 -
The Journal of the Acoustical Society... Jan 2023Synthetic vocal fold (VF) replicas were used to explore the role of nodule size and stiffness on kinematic, aerodynamic, and acoustic measures of voiced speech...
Synthetic vocal fold (VF) replicas were used to explore the role of nodule size and stiffness on kinematic, aerodynamic, and acoustic measures of voiced speech production. Emphasis was placed on determining how changes in collision pressure may contribute to the development of phonotrauma. This was performed by adding spherical beads with different sizes and moduli of elasticity at the middle of the medial surface of synthetic silicone VF models, representing nodules of varying size and stiffness. The VF models were incorporated into a hemilaryngeal flow facility. For each case, self-sustained oscillations were investigated at the phonation threshold pressure. It was found that increasing the nodule diameter increased the open quotient, phonation threshold pressure, and phonation threshold flow rate. However, these values did not change considerably as a function of the modulus of elasticity of the nodule. Nevertheless, the ratio of collision pressure to subglottal pressure increased significantly for both increasing nodule size and stiffness. This suggests that over time, both growth in size and fibrosis of nodules will lead to an increasing cycle of compensatory vocal hyperfunction that accelerates phonotrauma.
Topics: Vocal Cords; Pressure; Vibration; Phonation; Elasticity
PubMed: 36732229
DOI: 10.1121/10.0016997 -
Wiley Interdisciplinary Reviews.... May 2021African American Language (AAL) is one of the most researched varieties of American English, yet key aspects of its development and spread remain under-theorized. For... (Review)
Review
African American Language (AAL) is one of the most researched varieties of American English, yet key aspects of its development and spread remain under-theorized. For example, regional and social variation in the speech of African Americans was initially understudied in AAL as scholars sought to demonstrate the overall systematicity of the variety, often at the expense of examining variation across and within communities. More recently, scholars have begun to address this gap by examining different sources of variation in AAL phonology. For instance, the African American Vowel System (AAVS), also called the African American Vowel Shift, describes a pattern identified within AAL, including the raising of the front lax vowels and the nonfronting of the high- and mid-back vowels. Aspects of the AAVS have been found in geographically widespread varieties of AAL, suggesting that shared patterns of population movement resulting from the Great Migration and subsequent social experiences may have led to the development of this system. Other more regionally limited sound patterns suggest the role of more localized processes of variation and change. We focus on three sources of variation that have contributed to the spread and realizations of the sound system in modern AAL: migration, segregation, and place and identity. Evidence from sociophonetic analyses across these three factors provides a foundation to more thoroughly document the ways in which AAL varieties developed, spread, and vary, while allowing for a more nuanced assessment of racialization and its implications for individual differences. This article is categorized under: Linguistics > Linguistic Theory Psychology > Language.
Topics: Black or African American; Geography; Humans; Phonation; Phonetics; Speech; Speech Acoustics
PubMed: 33433053
DOI: 10.1002/wcs.1550 -
The Laryngoscope Aug 2016In speech and singing, the intrinsic laryngeal muscles set the prephonatory posture prior to the onset of phonation. The timing and shape of the prephonatory glottal...
INTRODUCTION
In speech and singing, the intrinsic laryngeal muscles set the prephonatory posture prior to the onset of phonation. The timing and shape of the prephonatory glottal posture can directly affect the resulting phonation type. We investigated the dynamics of human laryngeal phonatory posturing.
METHODS
Onset of vocal fold adduction to phonation was observed in 27 normal subjects using high-speed video recording. Subjects were asked to utter a variety of phonation types (modal, breathy, pressed, /i/ following sniff). Digital videokymography with concurrent acoustic signal was analyzed to assess the timing of the following: onset of adduction to final phonatory posture (FPT), phonation onset time (POT), and phonatory posture time (PPT). Final phonatory posture time was determined as the moment at which the laryngeal configuration used in phonation was first achieved.
RESULTS
Thirty-three audiovisual recordings met inclusion criteria. Average FPT, PPT, and POT were as follows: 303, 106, and 409 ms for modal; 430, 104, and 534 ms for breathy; 483, 213, and 696 ms for pressed; and 278, 98, and 376 ms for sniff-/i/. The following posturing features were observed: 1) pressed phonation: increased speed of closure just prior to final posture, complete glottal closure, and increased supraglottic hyperactivity; and 2) breathy phonation: decreased speed of closure prior to final posture, increased posterior glottal gap, and increased midmembranous gap.
CONCLUSIONS
Phonation onset latency was shortest for modal and longest for pressed voice. These findings are likely explained by glottal resistance and subglottal pressure requirements.
LEVEL OF EVIDENCE
NA. Laryngoscope, 126:1837-1843, 2016.
Topics: Glottis; Humans; Phonation
PubMed: 26690882
DOI: 10.1002/lary.25816 -
Journal of Biomedical Optics Aug 2023The vocal folds are critically important structures within the larynx which serve the essential functions of supporting the airway, preventing aspiration, and phonation....
SIGNIFICANCE
The vocal folds are critically important structures within the larynx which serve the essential functions of supporting the airway, preventing aspiration, and phonation. The vocal fold mucosa has a unique multilayered architecture whose layers have discrete viscoelastic properties facilitating sound production. Perturbations in these properties lead to voice loss. Currently, vocal fold pliability is inferred clinically using laryngeal videostroboscopy and no tools are available for objective assessment.
AIM
The main objective of the present study is to evaluate viability of Brillouin microspectroscopy for differentiating vocal folds' mechanical properties against surrounding tissues.
APPROACH
We used Brillouin microspectroscopy as an emerging optical imaging modality capable of providing information about local viscoelastic properties of tissues in noninvasive and remote manner.
RESULTS
Brillouin measurements of the porcine larynx vocal folds were performed. Elasticity-driven Brillouin spectral shifts were recorded and analyzed. Elastic properties, as assessed by Brillouin spectroscopy, strongly correlate with those acquired using classical elasticity measurements.
CONCLUSIONS
These results demonstrate the feasibility of Brillouin spectroscopy for vocal fold imaging. With more extensive research, this technique may provide noninvasive objective assessment of vocal fold mucosal pliability toward objective diagnoses and more targeted treatments.
Topics: Animals; Swine; Vocal Cords; Larynx; Phonation; Elasticity; Spectrum Analysis
PubMed: 37560326
DOI: 10.1117/1.JBO.28.8.087002 -
Medicina (Kaunas, Lithuania) Jul 2023Learning to speak properly requires a fully formed brain, good eyesight, and a functioning auditory system. Defective phonation is the outcome of a failure in the... (Review)
Review
Learning to speak properly requires a fully formed brain, good eyesight, and a functioning auditory system. Defective phonation is the outcome of a failure in the development of any of the systems or components involved in speech production. Dentures with strong phonetic skills can be fabricated with the help of a dentist who has a firm grasp of speech production and phonetic characteristics. Every dentist strives to perfect their craft by perfecting the balance between the technical, cosmetic, and acoustic aspects of dentistry, or "phonetics". The ideal prosthesis for a patient is one that not only sounds good but also functions well mechanically and aesthetically. Words are spoken by using articulators that alter their size and form. : Therefore, a prosthesis should be made in such a way that it does not interfere with the ability to communicate. As a result, a prosthodontist has to have a solid grasp of how speech is made and the numerous parts that go into it.
Topics: Humans; Speech; Phonetics; Phonation; Learning; Brain
PubMed: 37512133
DOI: 10.3390/medicina59071322 -
Problemy Endokrinologii Jan 2022Dysphonia is a symptom of many endocrine pathologies. Hoarseness, voice fatigue, decrease of the voice pitch, reduce of the range are typical complaints for... (Review)
Review
Dysphonia is a symptom of many endocrine pathologies. Hoarseness, voice fatigue, decrease of the voice pitch, reduce of the range are typical complaints for hypothyroidism, caused by an increased amount of polysaccharides and accumulation of fluid in the lamina propria of the vocal folds. An excess of growth hormone causes an overproduction of insulin-like growth factor-1, which leads to abnormalities in the craniofacial region and proliferation of the upper respiratory tract tissues, including thickening of the laryngeal cartilages, vocal folds and decreasing of the voice pitch. Hyperglycemia, changes in the balance of fluid and electrolytes in diabetes mellitus can indirectly affect the voice: xerostomia complicates phonation due to impaired hydration of the laryngeal mucosa, diabetic neuropathy often disrupts the work of the laryngeal muscles involved in voice formation. Voice changes are observed not only in endocrine disorders, but also during puberty, the phases of the menstrual cycle and during menopause. Laryngeal structures are modified under the influence of hormones and external factors, which generally changes pitch and intensity of the voice, timbre and resonance, articulation and prosodic characteristics. The purpose of this review is to summarize and systematize data on physiological and pathological voice changes in patients of different age groups and sex. The possibilities of a multidisciplinary approach to rational voice correction are demonstrated.
Topics: Dysphonia; Endocrine System Diseases; Female; Hoarseness; Humans; Laryngeal Muscles; Phonation; Voice
PubMed: 35488756
DOI: 10.14341/probl12822 -
CoDAS Apr 2016Teachers are professionals with high prevalence of dysphonia, whose main risk factors are the large work hours in classrooms with the presence of background noise. The... (Observational Study)
Observational Study
Teachers are professionals with high prevalence of dysphonia, whose main risk factors are the large work hours in classrooms with the presence of background noise. The purpose of the study was to calculate the phonation time and the cycle dose of teachers with dysphonia and teachers without voice disorders during the class. There were two groups analyzed: five teachers with functional dysphonia were the first group and five teachers without voice disorders were the second group. For the data was used the VoxLog® dosimeter and the parameters were: intensity; fundamental frequency; phonation time and cycle dose. The statistical analysis used ANOVA, Student's T-test, and Kruskal-Wallis test. Dysphonic teachers showed major values of phonation time and cycle dose compared with teachers without voice disorders. The dysphonia is related to extended period of speech time and greater exposure of the tissue of the vocal fold to phonotrauma.
Topics: Adult; Analysis of Variance; Dysphonia; Female; Humans; Middle Aged; Occupational Diseases; Phonation; Reference Values; Risk Factors; School Teachers; Speech Acoustics; Speech Production Measurement; Statistics, Nonparametric; Time Factors
PubMed: 27191884
DOI: 10.1590/2317-1782/20162015156 -
JNMA; Journal of the Nepal Medical... 2018The term 'voice' is the acoustic energy generated from the vocal tract that are characterized by their dependence on vocal fold vibratory pattern. Teachers as...
INTRODUCTION
The term 'voice' is the acoustic energy generated from the vocal tract that are characterized by their dependence on vocal fold vibratory pattern. Teachers as professional voice users are afflicted with dysphonia and are discouraged with their jobs and seek alternative employment. Loud speaking and voice straining may lead to vocal fatigue and vocal fold tissue damage. The objective of the study is to assess the quality of voice of school teachers before and after teaching practice.
METHODS
Sixty teachers from various schools, volunteered to participate in this study. Acoustic analysis Doctor Speech Tiger Electronics, USA was used to assess the voice quality of the school teachers before and after teaching practice. The data were collected and analyzed using Doctor Speech Tiger Electronics, USA. Analysis was performed in terms of perturbation (jitter and shimmer), fundamental frequency, harmonic to noise ratio and maximum phonation time.
RESULTS
We found statistically significant difference in all the four parameters except the Jitter value. The fundamental frequency and shimmer value has significantly increased (P<0.001) and (P=0.002) respectively after teaching practice. Unlikely, there was significant decrease in harmonic to noise ratio value (P<0.001) and maximum phonation time value (P<0.01) after teaching practice.
CONCLUSIONS
Vocal abuse, overuse, or misuse in teaching practice over a long period of time can result in inadequate phonatory pattern due to vocal fold tissue damage, which ultimately results in vocal nodules or polyps. So voice evaluation is particularly important for professional voice users and for the people who are concerned about their quality of voice.
Topics: Adult; Female; Humans; Laryngoscopy; Middle Aged; Nepal; Occupational Diseases; Phonation; School Teachers; Speech Acoustics; Vocal Cords; Voice Disorders; Voice Quality
PubMed: 30381759
DOI: No ID Found -
Journal of Voice : Official Journal of... Jul 2023Caffeine is considered a dehydrating agent due to its diuretic effects and influences the body's fluid balance. The relationship between voice and hydration has been...
BACKGROUND
Caffeine is considered a dehydrating agent due to its diuretic effects and influences the body's fluid balance. The relationship between voice and hydration has been widely investigated and it is accepted that inadequate hydration has detrimental effects on phonation. Since dehydration negatively affects the vocal folds and caffeine is considered a dehydrating agent, it can be hypothesized that voice might be negatively affected by caffeine intake. This systematic review aims to summarize and appraise the available evidence regarding the effects of caffeine on voice.
METHODS
Randomized and non-randomized experimental studies of healthy participants were retrieved following an electronic searching of six databases in June 2020. No publication, language or date restrictions were applied. Data extraction of relevant data and risk of bias assessment was conducted independently by two reviewers.
RESULTS
Five non-randomized experimental studies were deemed eligible for inclusion. The format of the administered interventions in the included studies was either liquid (coffee) or solid (caffeine tablets). Reported outcome measures used to examine the effects of caffeine on phonation consisted of acoustic, aerodynamic and (auditory & self-) perceptual. No measures were adversely affected by caffeine consumption.
CONCLUSION
Clinicians commonly advise patients to refrain from caffeine, as caffeine intake increases diuresis with subsequent effects on fluid balance. Such imbalances can potentially induce dehydration which can be detrimental to phonation. This notion cannot be supported empirically, as the evidence is deemed unreliable and no firm conclusions can be elicited to guide clinical practice. The results of this review demonstrate the lack of research in the field and the necessity for future investigations in order to inform evidence-based practice through reliable and valid outcomes.
Topics: Humans; Caffeine; Voice Quality; Dehydration; Voice; Phonation; Randomized Controlled Trials as Topic
PubMed: 33752928
DOI: 10.1016/j.jvoice.2021.02.025