Conselho Nacional de Desenvolvimento Científico e Tecnológico / Vocal exercises semioccluded vocal tract (SOVT) of include finger kazoo (FK). Objectives: to correlate vocal-acoustic and auditory perception modifications of the glottal source, spectrograph acoustic vocal modifications and self-evaluation after FK. Methods: A cross-sectional analytic quantitative observation study. The 46 adult women age between 18 and 40 without vocal complaints and laryngeal alterations, emitted the vowel /a:/ before (M1); immediately after three series of 15 FK repetitions (30 seconds rest) (M2); and five minutes after (M3); vocal self-evaluation in M2 and M3. Vocal analyses by means of the RASATI scale, programs Multi Dimension Voice Program Advanced and Real Time Spectrogram (Kay Pentax®). The spectrographs and the RASATI results were evaluated by judges. Kappa, Friedman, Wilcoxon and Chi-square tests. Results: Increase of fundamental frequency (f0); reduction of amplitude variation (vAm); and degree of sub-harmonics (DSH) in M2. No difference in the RASATI. Significant positive correlations: standard deviation of the f0 (STD) with breathiness and asthenia; measures of jitter, frequency variation (vf0) and soft phonation index (SPI) with hoarseness, breathiness, asthenia, and instability; measures of shimmer and vAm with hoarseness and breathiness; vAm with asthenia; degree and number of unvoiced segments (NUV and DUV) with breathiness; STD, jita, SPI, smoothed pitch perturbation quotient (sPPQ), smoothed amplitude perturbation quotient (sAPQ), vf0 and vAm with instability. Significant negative correlations: voice turbulence index (VTI) with asthenia; jitter and SPI measures with tension; f0 higher (fhi), f0 lower (flo) and f0 with hoarseness and breathiness; instability with flo. Wideband: improvement of F2, F3, F4 intensity and of high frequencies (hf), F2, F3 definition and trace regularity (M1XM2); F and hf intensity, and F3, F4 definition, increase in hf noise (M1XM3), worsening in the trace regularity (M2XM3). No alteration (NA) in F bandwidth, F1 definition, low, medium and hf noise (M1XM2XM3), and medium and low frequencies M1XM3). Narrowband: improvement in hf intensity, harmonics definitions and trace regularity, NA in noise between low harmonics and hf (M1XM2); improvement of hf intensity, in all vocal spectrogram and trace regularity, worsening in noise between harmonics, NA in low and hf noise, harmonics substitution for noise in all vocal spectrogram and low, medium and hf (M1XM3); NA in the presence of subharmonics (M1XM2XM3). Improvement in voice reference. Positive correlation between better voice and F3 intensity (wideband M1XM3), and harmonics substitution for noise in medium frequencies, definition and harmonics number (narrowband - M1XM3). Conclusion: FK generated noise reduction, increase of f0, vocal stability and harmonic energy. In general, hoarseness, asthenia, breathiness and instability positively correlated with jitter, shimmer, STD, SPI, vf0, vAm, NUV, DUV measures and negatively with frequency and VTI measures. The tension negatively correlated with jitter and SPI measures. There was an increase in hf intensity, F intensity and definition, trace regularity and harmonics definition. Better voice, according to F3 intensity, definition and number of harmonics and harmonics substitution for noise in medium frequencies. Keywords: Voice. Phonation. Rehabilitation. Speech Acoustics / Exercícios fonoterapêuticos de trato vocal semiocluído (ETVSO) incluem o finger kazoo (FK). Objetivo: correlacionar modificações vocais acústicas e perceptivo-auditivas de fonte glótica e modificações vocais espectrográficas e autoavaliação vocal após FK. Métodos: Estudo observacional transversal analítico quantitativo. Amostra de 46 mulheres adultas entre 18 e 31 anos de idade sem queixas vocais e afecções laríngeas. Coleta de /a:/ antes (M1); imediatamente após três séries de 15 repetições do FK (30 segundos de repouso) (M2); e cinco minutos após (M3); autoavaliação vocal em M2 e M3. Análises pela escala RASATI, programas Multi Dimension Voice Program Advanced e Real Time Spectrogram (Kay Pentax®). As espectrografias e os resultados da RASATI foram avaliados por juízes. Testes de Kappa, Friedman, Wilcoxon e Qui-quadrado. Resultados: Aumento significativo da frequência fundamental (f0), redução da variação de amplitude (vAm) e grau de sub-harmônicos (DSH) em M2. RASATI sem significâncias. Correlações positivas significativas: desvio-padrão f0 (STD) com soprosidade e astenia; medidas de jitter, variação de frequência (vf0) e índice de fonação suave (SPI) com rouquidão, soprosidade, astenia e instabilidade; medidas de shimmer e vAm com rouquidão e soprosidade; vAm com astenia; grau e número de segmentos não sonorizados (DUV e NUV) com soprosidade; STD, jita, SPI, quociente de perturbação do pitch suavizado (sPPQ), quociente de perturbação da amplitude suavizado (sAPQ), vf0 e vAm com instabilidade. Correlações negativas significativas: índice de turbulência (VTI) com astenia; medidas de jitter e SPI com tensão; f0 mais aguda (fhi), f0 mais grave (flo) e f0 com rouquidão e soprosidade; instabilidade com flo. Banda larga (EBL): melhora da intensidade F2, F3, F4 e altas frequências (af), definição F2, F3 e regularidade do traçado (M1XM2); intensidade de dos F e af, e definição F3, F4, aumento do ruído af (M1XM3); piora da regularidade do traçado (M2XM3). Sem alterações (SA) largura de banda dos F, definição F1, ruído baixas, médias e af (M1XM2XM3), e médias e baixas frequências (M1XM3). Banda estreita (EBE): melhora da intensidade af, definição harmônicos e regularidade do traçado, SA ruído entre harmônicos baixas e af (M1XM2); melhora da intensidade af, de todo espectrograma vocal e regularidade do traçado, piora do ruído entre harmônicos, SA ruído baixas e af, substituição de harmônicos por ruído em todo espectrograma vocal e baixas, médias e af (M1XM3); SA presença de sub-harmônicos (M1XM2XM3). Referência de voz melhor. Correlação positiva entre voz melhor e intensidade F3 (EBL - M1XM3), e substituição de harmônicos por ruído nas médias frequências, definição e número de harmônicos (EBE - M1XM3). Conclusão: FK gerou redução do ruído, aumento da f0, estabilidade vocal e energia harmônica. No geral, rouquidão, astenia, soprosidade e instabilidade correlacionaram-se positivamente com medidas de jitter, shimmer, STD, SPI, vf0, vAm, NUV, DUV e negativamente com medidas de frequência e VTI. A tensão correlacionou-se negativamente com medidas de jitter e SPI. Aumento da intensidade das af, intensidade e definição dos F, regularidade do traçado e definição dos harmônicos. Melhor voz, conforme aumento da intensidade F3, definição e número de harmônicos e substituição de harmônicos por ruído nas médias frequências.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The development of children s vocal apparatus reflects in their voice characteristics. Objectives: To review the characteristics of the child s voice; to assess and correlate the results of the acoustic analysis of the glottal source, maximum phonation times (MPT), body height and body mass index (BMI) of children aged 4-8 years. Methods: A sample of 484 eutrophic children without a speech-language pathology diagnosis of dysphonia; mailing of questionnaires to parents; auditory screening; BMI determination, and auditory-perceptual analysis of voice (CAPE-V scale); acoustic assessment of /a:/ using the Multi Dimensional Voice Program Advanced; /a,i,u/ MPT measurements; descriptive statistics analysis, t-test and multiple regression (SPSS, significance at 5%). Results: hoarseness and/or breathiness is expected, as well as voice instability; increased loudness, and hard glottal attack; lowered fundamental frequency (f0) as the child grows; measures of jitter, shimmer, noise-to-harmonics ratio (NHR), and voice turbulence index (VTI) tend to be higher in younger children and decrease with body growth and increasing age; due to the maturation of the structures, increased soft phonation index (SPI) is also expected; MPT in seconds parallels the child s age in years, with slightly more sustained phonation than the respective chronological age. In childhood, voice disorders are frequent and more prevalent in boys, with characteristics such as hoarseness and breathiness; lowered f0 and increased jitter and shimmer in dysphonic voices. Original papers: lower f0 as age increases; lower f0 values in girls; greater jitter, shimmer, and VTI measures in girls at six years; higher SPI in boys at seven years; negative correlations between f0, height, and BMI at four years; positive correlations between height and BMI and measures of jitter, shimmer, and VTI, as well as between height and NHR in girls at five years; variability in amplitude and height at seven years in girls; SPI and height in boys at five and seven years. Mean /a/ MPTs for boys at four, five, six and seven years, respectively: 3.77s, 5s, 5.85s, and 7.5s. Mean /a/ MPTs for girls at the same ages: 3.89s, 4.89s, 5.61s, and 6.61s, respectively. Mean /i/ MPTs for boys: 3.49s, 4.96s, 5.72s, and 6.88s. Mean /i/ MPTs for girls: 3.49s, 4.73s, 5.41s, and 6.63s. Mean /u/ MPTs for boys: 3.64s, 4.85s, 5.76s, and 7.08s. Mean /u/ MPTs for girls: 3.54s, 4.73s, 5.64s, and 6.47s. Longer /a/ MPT in boys at seven years, which correlated positively with height. Conclusion: Body height seemed to be the anthropometric measure with the greatest correlation to the acoustic measures, predominantly in girls. The age ranges showing acoustic abnormalities coincided with those rated as having mild deviance in auditory-perceptual analysis. Children s MPT increases with age; /a,i,u/ MPTs in seconds follow the age in years; at seven years, /a/ MPT was longer for boys and influenced by body height, while BMI had no influence on MPT. / O aparato vocal da criança se desenvolve com reflexos nas características acústicas da voz. Objetivo: realizar revisão sobre características da voz de crianças, verificar e correlacionar os resultados da análise acústica de fonte glótica, tempos máximos de fonação (TMF), estatura e índice de massa corporal (IMC) de crianças com voz considerada normal. Método: Amostra de 484 crianças de quatro a oito anos, eutróficas com voz considerada normal; envio de questionário aos pais, triagem auditiva, avaliação do IMC e análise vocal perceptivo-auditiva (Escala CAPE-V); análise acústica de /a:/ pelo Multi Dimensional Voice Program Advanced; obtenção dos TMF/a,i,u/; análise estatística descritiva, Teste t e regressão múltipla (SPSS, significância de 5%). Resultados: discreto grau de rouquidão e/ou soprosidade, instabilidade, loudness aumentada e ataque vocal brusco; diminuição da frequência fundamental (f0) conforme a criança cresce; medidas de Jitter, Shimmer, proporção ruído-harmônico (NHR) e índice de turbulência da voz (VTI) tendem a ser maiores em crianças jovens, diminuindo com o crescimento e aumento da idade; pela maturação das estruturas, espera-se, igualmente, aumento dos valores de índice de fonação suave (SPI); TMF em segundos gira em torno número de anos de idade da criança, podendo observar-se sustentações discretamente maiores do que as idades cronológicas. Na infância os distúrbios vocais comportamentais são frequentes e prevalentes nos meninos, com características como rouquidão e soprosidade; f0 mais grave e aumento das medidas de Jitter e Shimmer nas vozes disfônicas. Observou-se: Diminuição de f0 com o aumento da idade; medidas de f0 mais graves nas meninas, Jitter, Shimmer e VTI maiores nas meninas aos seis anos; SPI maior nos meninos aos sete anos; correlação negativa: entre medidas de f0, estatura e IMC aos quatro anos; correlação positiva entre: estatura e IMC e medidas de Jitter, Shimmer e VTI, bem como entre estatura e NHR nas meninas aos cinco anos; variação da amplitude e estatura aos sete anos nas meninas; SPI e estatura nos meninos, aos cinco e sete anos. Média TMF/a/ de 3,77s aos quatro anos, 5s aos cinco, 5,85s aos seis e 7,5s aos sete nos meninos, nas meninas respectivamente de 3,89s, 4,89s, 5,61s, e 6,61s; TMF/i/ 3,49s aos quatro, 4,96s aos cinco, 5,72s aos seis e 6,88s aos sete nos meninos, nas meninas respectivamente de 3,49s, 4,73s, 5,41s, e 6,63s; TMF/u/ 3,64s aos quatro, 4,85s aos cinco, 5,76s aos seis e 7,08s aos sete nos meninos, nas meninas respectivamente de 3,54s, 4,73s, 5,64s, e 6,47s. TMF/a/ maior nos meninos aos sete anos com correlação positiva com a estatura. Conclusão: estatura pareceu ser a medida antropométrica de maior correlação com as medidas acústicas, relação observada predominantemente nas meninas. As faixas etárias que apresentaram alterações acústicas coincidiram com aquelas classificadas com alteração discreta na avaliação perceptivo-auditiva. Os TMF de crianças aumentam com a idade; TMF/a,i,u/ em segundos ficaram em torno do número de anos de idade; aos sete anos, TMF/a/ foi maior nos meninos, sendo afetado pela estatura; o IMC não mostrou influência sobre os TMF.

Introduction: Singers perform elite vocals, represent a professional class with high vocal demand, with different degrees of demands and refinements. In this sense, tube phonation exercises have been widely used in clinical practice to favor speech economy and efficiency, facilitate source-filter interaction, and reduce the risks of work-related voice disorders. Aim: To verify, through a systematic review of the literature, the effects of phonation on tubes on vocal quality, glottal function and/or vocal tract of the singers. Methods: We searched the literature, without restrictions regarding the publication period, in the Portuguese, English and Spanish languages, in the databases Lilacs, Scielo, PubMed and Cochrane. Eligible articles were subjectively assessed for methodological quality based on the checklist proposed by the Joanna Briggs Institute for observational studies. Resuts: The research resulted in a sample of 1,715 papers. The verifications of the records were done by two evaluators, obtaining an excellent level of agreement (Kappa = 0.88). At the end of the process, 05 studies fell within the eligibility criteria. To evaluate the effects of the phonation exercise in tubes, the studies used vocal self-assessment, perceptual-auditory analysis, acoustic analysis, aerodynamic measurements and electroglotography. The tubes used were plastic straws (02), glass tube immersed in water (01), glass tube in the air (01) and LaxVox (01). Conclusion: In general, studies showed that phonation in tubes in singers produced positive effects on vocal quality, with greater vocal comfort and vocal projection, more economic emission, increased collision threshold during phonation in water-immersed tube and intraoral pressures more consistent with phonation in narrow straws, favoring efficient and effective vocal therapy. / Introdução: Os cantores, considerados interpretes vocais de elite, representam uma classe profissional geralmente de alta demanda vocal, com diferentes graus de exigências e requintes. Neste sentido, os exercícios de fonação em tubos têm sido amplamente utilizados na prática clínica para favorecer a economia e eficiência da voz, facilitar a interação fonte-filtro e reduzir os riscos de distúrbios da voz relacionados ao trabalho. Objetivo: Verificar, por meio de uma revisão sistemática da literatura, os efeitos da fonação em tubos sobre a qualidade da voz, função glótica e/ou trato vocal dos cantores. Métodos: Foi realizada uma busca na literatura, sem restrições quanto ao período de publicação, nos idiomas português, inglês e espanhol, nas bases de dados Lilacs, Scielo, PubMed e Cochrane. Os artigos elegíveis foram avaliados subjetivamente quanto à qualidade metodológica com base no checklist proposto pelo Instituto Joanna Briggs para estudos observacionais. Resultados: A pesquisa resultou em uma amostra de 1.715 trabalhos. As verificações dos registros foram feitas por dois avaliadores, sendo obtido um nível de concordância excelente (Kappa = 0,88). Ao final do processo, 05 estudos se enquadraram nos critérios de elegibilidade. Para avaliar os efeitos do exercício de fonação em tubos, os estudos utilizaram autoavaliação vocal, análise perceptivo-auditiva, análise acústica, medidas aerodinâmicas e eletroglotografia. Os tubos utilizados foram canudos plásticos (02), tubo de vidro imerso em recipiente com água (01), tubo de vidro no ar (01) e LaxVox (01). Conclusão: Em geral, os estudos demonstraram que a fonação em tubos em cantores produziu efeitos positivos sobre a qualidade vocal, com maior conforto fonatório e projeção vocal, emissão mais econômica, aumento do limiar de colisão durante a fonação em tubo imerso em água e pressões intraorais mais consistentes após a fonação em canudo estreito, favorecendo à terapia vocal eficiente e efetiva. / Lagarto, SE

This thesis presents tools and components necessary to further develop an implementation of a method. The method attempts to use the non invasive electroglottographic signal to locate rapid transitions between voice registers. Implementations for sample entropy and the Discrete Fourier Transform (DFT) implemented for the programming language SuperCollider are presented along with tools necessary to evaluate the method and present the results in real time. Since different algorithms have been used, both for clustering and cycle separation, a comparison between algorithms for both of these steps has also been done. / Denna rapport presenterar verktyg och komponenter som är nödvändiga för att vidareutveckla en implementation av en metod. Metoden försöker att använda en icke invasiv elektroglottografisk signal för att hitta snabba övergångar mellan röstregister. Det presenteras implementationer för sampelentropi och den diskreta fourier transformen för programspråket SuperCollider samt verktyg som behövs för att utvärdera metoden och presentera resultaten i realtid. Då olika algoritmer har använts för både klustring och cykelseparation så har även en jämförelse mellan algoritmer för dessa steg gjorts.

Several studies involving excised animal larynges have been performed to simulate the structural and physiological properties of the human larynx. The most common way to preserve the laryngeal tissue being studied is by immersing it in a 0.9% isotonic saline solution and then flash freezing it. Isotonic saline is used empirically to replenish the potential ion loss that occurs postmortem. Each larynx is flash frozen so it can be used at a more convenient time while still maintaining the integrity of the tissue. However, the preservation methods found in previous studies tend to vary and no consensus had been reached about which method of preservation is ideal. This study sought to investigate the effects of solution and storage on phonation threshold pressure (PTP). Phonation threshold pressure is commonly used to investigate mucosal wave of the vocal folds, prephonatory glottal width, and vocal fold cover. This study involved a prospective, mixed experimental design with three groups, including a control group and two experimental groups. Each group consisted of 10 bench-mounted porcine larynges. The control group was immersed in 0.9% isotonic saline, flash frozen with liquid nitrogen within 24 hours postmortem, and thawed overnight before the experiment. The second group was immersed in 0.9% isotonic saline and the third group was submersed in Ringer's solution. Each of these groups was kept in their solution in a refrigerator for approximately 15 hours and was used for the experiment within 24 hours postmortem. Each larynx was mounted on a bench on a tabletop with three micropositioners to adduct and elongate the vocal folds. A pseudolung connected to the trachea directed humidified air to the vocal folds subglottally until phonation was achieved. The larynges in all three groups underwent these phonatory trials with 5-minute desiccation trials between each until phonation could no longer be achieved. Phonation threshold pressure was then observed and compared within groups and between groups. The signals were obtained using MATLAB. The results indicated that PTP was lowest for the frozen versus fresh groups. PTP values increased slightly for the frozen group, but the frozen group demonstrated less variability across specimens as compared to the fresh groups. Collectively, these results indicate that there are substantial differences between fresh and frozen specimens. These differences should be considered when designing tissue studies for purposes of generalization to human phonation.

The purpose of the present study was to examine the effects of external laryngeal vibration on voice function. The current study was based on a recent pilot study using silicone vocal folds that demonstrated a decrease in phonation threshold pressure (PTP; cmH2O) when an external oscillation was applied to the vocal folds. Using a within-subjects experimental design, a custom external oscillatory device was fitted to the posterior portion of 12 excised pig larynges using a traditional benchtop phonation setup. For each larynx, phonation was elicited during 30 repeated trials, including 15 with and 15 without external oscillation. During the phonation trials, aerodynamic measures were collected. The outcome measure for this study was PTP, which has been established in the literature as being correlated with physiologic and self-perceived vocal effort. Furthermore, PTP is used routinely as an aerodynamic indicator of voice function, vocal efficiency, and the nature and severity of voice disorders. Although the aim was to quantify either positive (i.e., PTP decrease) or negative (i.e., PTP increase) effects of external oscillation on PTP, it was hypothesized that external oscillation would result in a reduction in average PTP values. The results of the study indicate that application of an external oscillatory device results in significantly lower PTP. These findings have important clinical implications for PTP signal acquisition and the potential use of external oscillation as a therapeutic tool to improve voice function.

Hydration of the vocal folds is important for the production of normal voice. Dehydration makes voice production more difficult and increases vocal effort. Laryngeal desiccation has been shown to increase phonation threshold pressure (PTP) and self-perceived phonatory effort (PPE) in females. Nebulized saline may reverse or offset this effect. However, few data exist regarding the effects of laryngeal desiccation and nebulized treatments in males. Further, the dose-response relationship between laryngeal desiccation and nebulized hydration treatments is unknown. This study examined the effects of two doses of nebulized isotonic saline following a laryngeal desiccation challenge in healthy male speakers. In a double-blinded, within-subjects design, 10 male college students (age range 18-26 years) attended two data collection sessions involving a 30-minute desiccation challenge followed by 3 mL or 9 mL of nebulized isotonic saline. PTP for the 10th and 80th fundamental frequency (F0) percentiles and PPE were collected before and after the desiccation challenge and at 5, 35, and 65 minutes after the nebulized treatment. PPE increased significantly following the laryngeal desiccation challenge (p < .01). Following nebulization, PPE decreased toward baseline for both doses of isotonic saline (p < .01), but failed to reverse the desiccation effect completely. No statistically significant changes in PTP occurred following the laryngeal desiccation challenge or subsequent treatments. Compared with previous research involving females, these results suggest males may respond differently to laryngeal desiccation and nebulized hydration treatments.

Vocal fold hydration is important for healthy function of the vocal mechanism. Vocal fold surface fluid protects the mucosa and facilitates efficient vocal fold oscillation. Dry air exposure, mouth breathing, insufficient intake of liquids, and behavioral factors may contribute to laryngeal dehydration. Singers are believed to be particularly at risk for voice problems related to dehydration due to environmental and voice use factors. Laryngeal desiccation and nebulized hydration treatments have been shown to influence phonation threshold pressure (PTP) and self-perceived phonatory effort (PPE) in females. However, little research exists exploring the effects of hydration in males. Additionally, few studies have examined the dose-response relationship of hydration treatments. This investigation examined the effects of a laryngeal desiccation challenge and two different doses of nebulized isotonic saline on voice production in trained male singers. In a double-blind, within-subjects repeated measures crossover investigation, 10 male singers (ages 18 to 24) received a 30 minute laryngeal desiccation challenge followed by either 3 mL or 9 mL of nebulized isotonic saline on two consecutive weeks. PTP, PPE, and self-perceived mouth and throat dryness were sampled during the following observations: predesiccation, post-desiccation, and at 5, 35, and 65 minutes post-nebulization. No differences in PTP were observed after desiccation or nebulized treatment. PPE, however, rose significantly after desiccation and returned near baseline after treatment. No significant differences between dosages were observed.

An excised animal larynx model has been used in many studies to better understand the physiological and anatomical properties of the human larynx. One difference between an ex vivo model and an in vivo model is that ion loss occurs postmortem. To compensate for this in the excised model, researchers most commonly use a preservation method that includes completely submerging the specimen in isotonic saline (0.9% Na+Cl-) and then flash freezing it in liquid nitrogen. The flash freezing method allows researchers to maintain the integrity of the structures while also being able to gather specimens as they become available. Not enough research has been done to understand the effects of a preservation method on the outcomes of the study. Additionally, no common method has been established for preservation across studies to ensure that results are not being influenced by this variable. This prospective, mixed experimental design study includes three groups, a control group and two experimental groups. The control group consisted of 10 bench-mounted porcine larynges that were soaked in isotonic saline and flash frozen with liquid nitrogen. Prior to the experiment, the frozen larynges were thawed overnight before trials. The other two groups consisted of 10 bench-mounted porcine larynges each; these larynges were soaked in either isotonic saline or Ringers solution, a balanced fluid used in vivo to counteract dehydration. Larynges from these two groups were kept fresh and stored in a refrigerator overnight before trials. On the day of experimentation, each larynx was mounted on a bench top setup including three micropositioners to stabilize, adduct, and elongate the vocal folds. All the larynges were connected to a pseudolung via the trachea and humidified air was passed through to the vocal folds until phonation was achieved. Phonatory trials consisted of brief phonation followed by 5-minute desiccation intervals until phonation was no longer achieved. Phonation threshold flow (PTF), defined as the flow observed at the onset of phonation, was observed during each phonation trial; and flow values were compared within and between groups. Statistically significant differences were found between the Ringers group and the fresh saline group as well as between the Ringers group and the frozen saline group, indicating that PTF is influenced by the larynx preservation method.

Subglottic stenosis (SGS) is an abnormal narrowing of the airway at the level of the cricoid cartilage, above the first tracheal ring and immediately beneath the vocal folds. Individuals with SGS experience a reduction in their ability to breathe as well as adverse effects on voice function. SGS can result from a variety of causes with the type of treatment depending on stenosis severity. Surgical techniques such as laryngotracheal and cricotracheal reconstruction are beneficial for airway maintenance; however, these procedures have resulted in negative effects on voice production. On the other hand, there are patients with SGS who do not require surgery and still experience voice problems. The purpose of this study was to quantify the effects of SGS on vocal fold vibration using an excised larynx benchtop mechanical model. Using a within-subjects repeated measures design, nine porcine larynges underwent experimental conditions including 0% (i.e., normal airway), 50% and 75% stenosed. The primary outcome measure was phonation threshold flow (PTF), which is the rate of flow observed at the onset of phonation. For all larynges, the normal and stenosed conditions were sampled three times each and averaged. Analysis of the results revealed no statistically significant differences in PTF; however, descriptive data showed decreases in PTF and increased variability in PTF values as percent stenosis increased. These findings lay important groundwork for future research in SGS, specifically those that employ ex vivo methodologies. PTF has emerged as a promising means of quantifying voice function in addition to the traditional onset pressure measures. Future studies should examine a broader range of stenosis conditions with a larger sample size to promote generalization to clinical populations including individuals with SGS.