An Investigation of Air Flow and Subglottal Air Pressure Related to Fundamental Frequency of Phonation

1966 ◽  
Vol 18 (5) ◽  
pp. 313-322
Author(s):  
R.E. McGlone
Keyword(s):  
Fundamental Frequency ◽  
Air Flow ◽  
Air Pressure

Evaluating the Influence of Targeted Air Flow on Sound Pressure Level and Closed Quotient

2021 ◽  
pp. 1-6
Author(s):  
Michael J. Hammer
Keyword(s):  
Fundamental Frequency ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Air Flow ◽  
Vocal Folds ◽  
Pressure Level ◽  
Air Pressure ◽  
Steady Increase ◽  
Closed Quotient ◽  
Considerable Range

Purpose Measures of estimated subglottal air pressure and translaryngeal air flow enable the researcher or clinician to noninvasively assess aerodynamic features related to respiratory and phonatory function. Our goal was to examine the unique relationship between air flow with sound pressure level (SPL) during syllable production while attempting to hold fundamental frequency and subglottal air pressure relatively constant. Method We completed two studies. Study 1: During syllable production, resultant sound pressure level was measured under conditions of constant fundamental frequency and estimated subglottal air pressure while systematically varying translaryngeal air flow. Study 2: During syllable production, resultant sound pressure level and closed quotient (using laryngeal stroboscopy) were measured under conditions of constant fundamental frequency and estimated subglottal air pressure while systematically varying translaryngeal air flow. Results Study 1: Findings suggest a steady increase in sound pressure level with increases in air flow between 25 cc/s and 150 cc/s. Interestingly, relatively stable mean sound pressure level was maintained over a considerable range of air flow values between 225 and 450 cc/s, suggesting that air flow could be further increased without a marked loss of sound pressure level. Study 2: Findings suggest a systematic increase in mean sound pressure level as supraglottic activity subsided and as the closed quotient decreased from 0.80 to 0.58. Interestingly, sound pressure level was relatively stable as the closed quotient decreased from 0.58 to 0.35. Conclusions Our findings suggest that sound pressure level can be maintained over a considerable range of increasing translaryngeal air flow values and over a considerable range of decreasing closed quotient values. These results provide motivation for investigating the interaction between air flow, glottal closure, and sound pressure level among other measures of phonatory function, with important clinical implications for therapeutic approaches that emphasize increases in air flow and focus on reducing contact between the vocal folds.

Vowel-Related Differences in Laryngeal Articulatory and Phonatory Function

1998 ◽  
Vol 41 (4) ◽  
pp. 712-724 ◽  
Author(s):  
Maureen B. Higgins ◽  
Ronald Netsell ◽  
Laura Schulte
Keyword(s):  
Fundamental Frequency ◽  
Neural Activity ◽  
Vocal Fold ◽  
Voice Onset Time ◽  
Air Flow ◽  
Onset Time ◽  
Air Pressure ◽  
New Findings ◽  
Pressure Peak ◽  
Speaking Task

The purpose of this investigation was to study the interaction between the supralaryngeal and laryngeal components of the speech mechanism by examining vowel-related effects for a variety of vocal fold articulatory and phonatory measures. Secondary issues were to determine if vowel-related differences were influenced by the nature of the speaking task or gender. Between-vowel differences in estimated subglottal air pressure, peak oral air flow, mean phonatory air flow, air flow near the termination of the vowel, electroglottograph cycle width (EGGW), fundamental frequency, and voice onset time were examined for men and women during syllable repetitions and sentence productions. Significant vowel-related differences were found for all of the measures except mean phonatory air flow, and generally were not influenced by speaking task or gender. Vowel-related effects for estimated subglottal air pressure, peak oral air flow, fundamental frequency, and VOT were consistent with some earlier studies. New findings included vowel-related differences in EGGW and air flow near the termination of the vowel. We propose a model that includes the contribution of mechanical forces, reflexive neural activity, and learned neural activity to explain vowel-related effects. When vowel height is varied, changes in laryngeal cartilage positioning and vocal fold and vocal tract tension appear to influence laryngeal articulatory and phonatory function.

Aerodynamic and Electroglottographic Measures of Normal Voice Production

1994 ◽  
Vol 37 (1) ◽  
pp. 38-45 ◽  
Author(s):  
Maureen B. Higgins ◽  
Ronald Netsell ◽  
Laura Schulte
Keyword(s):  
Fundamental Frequency ◽  
Air Flow ◽  
Air Pressure ◽  
Sentence Production ◽  
Type I ◽  
Intrasubject Variability ◽  
Voice Production ◽  
Normal Limits ◽  
Syllable Repetition ◽  
Normal Voice

The purpose of this investigation was to quantify the normal intrasubject performance variability of four measures of phonatory function within and across sessions. Two different speaking tasks, syllable series and sentence production, were used to determine if more natural speaking tasks resulted in greater intrasubject variability. Vowel type ([i] versus [a]) also was varied. Estimated subglottal air pressure, mean phonatory air flow, abduction quotient, and fundamental frequency were derived from aerodynamic and electroglottographic signals obtained from 11 normally speaking men and 10 normally speaking women on four different days. Relative intrasubject variability was compared across speaking task, gender, and vowel type. Average across-session intrasubject variability was 5% for fundamental frequency and abduction quotient, 8% for estimated subglottal air pressure, and 15% for mean phonatory air flow during syllable repetition. There was significantly greater intrasubject variability for mean phonatory air flow and abduction quotient for the sentence repetition task. There were no significant differences in intrasubject variability across gender and vowel type. The data were used to compute cutoff values that represent the amount of variability that would be considered within normal limits. These normal data can be used for comparison when assessing and monitoring the phonatory abilities of individuals with voice disorders.

Parametric study on pressure-based packed bed adsorption system for air dehumidification

2021 ◽  
pp. 095440892110073
Author(s):  
V Sureshkannan ◽  
TV Arjunan ◽  
D Seenivasan ◽  
SP Anbuudayasankar ◽  
M Arulraj
Keyword(s):  
Genetic Algorithm ◽  
Taguchi Method ◽  
Flow Rate ◽  
Uptake Rate ◽  
Air Flow ◽  
Packed Bed ◽  
Air Pressure ◽  
Dew Point ◽  
Adsorption System ◽  
Air Flow Rate

Compressed air free from traces of water vapour is vital in many applications in an industrial sector. This study focuses on parametric optimization of a pressure-based packed bed adsorption system for air dehumidification through the Taguchi method and Genetic Algorithm. The effect of operational parameters, namely absolute feed air pressure, feed air linear velocity, and purge air flow rate percent on adsorption uptake rate of molecular sieve 13X-water pair, are studied based on L25 orthogonal array. From the analysis of variance, it has been found that absolute feed air pressure and purge air flow rate percent were the parameters making significant improvement in the adsorption uptake rate. A correlation representing the process was developed using regression analysis. The optimum adsorption conditions were obtained through the Taguchi method and genetic algorithm and verified through the confirmation experiments. This system can be recommended for the industrial and domestic applications that require product air with the dew point temperature below 0°C.

Oral Air Pressure and Nasal Air Flow Rate on Levator Veli Palatini Muscle Activity in Patients Wearing a Speech Appliance

1995 ◽  
Vol 32 (5) ◽  
pp. 382-389 ◽  
Author(s):  
Takashi Tachimura ◽  
Hisanaga Hara ◽  
Takeshi Wada
Keyword(s):  
Flow Rate ◽  
Muscle Activity ◽  
Neural Control ◽  
Air Flow ◽  
Air Pressure ◽  
Electromyographic Activity ◽  
Air Flow Rate ◽  
Circular Area ◽  
Pharyngeal Bulb ◽  
Levator Veli Palatini

This study was designed to determine if levator veli palatini muscle activity can be elicited by simultaneous changes in oral air pressure and nasal air flow when a speech appliance is in place. The speech appliances routinely worn by 15 subjects were each modified experimentally by drilling a hole in the vertical center of the pharyngeal bulb. The air flow rate into the nasal cavity through the opening in the bulb was altered by changing the circular area of the opening in the bulb from the occluded condition (Condition I), to circular area of 12.6 mm2 (4 mm in diameter; Condition II), and then to 38.5 mm2 (7 mm in diameter; Condition III). Electromyographic activity was measured from the levator veli palatini muscle with changes in nasal air flow rate and oral air pressure. Levator veli palatini muscle activity was correlated with changes in nasal air flow and oral air pressure. Increases in levator veli palatini muscle activity were associated with increases in nasal air flow rate compared to oral air pressure changes. The results indicated that aerodynamic variables of nasal air flow and oral air pressure might be involved in the neural control of speech production in individuals wearing a speech appliance, even if the subjects exhibit velopharyngeal incompetence without using a speech appliance. Also, the stimulating effect of bulb reduction therapy on velopharyngeal function might be achieved through the change in aerodynamic variables in association with the bulb reduction.

Performance Analysis of Eductor Used for Main Control Room Ventilating in Nuclear Power Plant

2017 ◽  
Author(s):  
Xin Yu ◽  
Yuqing Lin ◽  
Yan Zhang
Keyword(s):  
Flow Rate ◽  
Nuclear Power ◽  
Air Flow ◽  
Test System ◽  
Air Pressure ◽  
Air Flow Rate ◽  
Control Room ◽  
Entrainment Ratio ◽  
Pressurized Water ◽  
Set Up

This paper proposes the experimental research for the performance of the air eductor used in main control room (MCR). The air eductor is used for emergency ventilating in advanced passive pressurized water reactor in accident. The compress air is supplied to the eductor as a power source and the indoor air is suctioned to the eductor. The performance of the eductor is related to the habitability of MCR. The entrainment ratio and the air pressure of discharge side are the main concerned performance. The entrainment ratio is a value that resulted from the compress air flow rate divided by the suction air flow rate. A test system was set up to test the performance of eductor. The experimental results show that the entrainment ratio of rectangle nozzle with compress air pressure 0.76MPa, 0.80MPa and 0.83MPa were 15.02, 15.04 and 15.06, respectively.

Through-thickness permeability of woven fabric under increasing air pressure: Theoretical framework and simulation

2016 ◽  
Vol 87 (13) ◽  
pp. 1631-1642 ◽  
Author(s):  
Xueliang Xiao ◽  
Andrew Long ◽  
Kun Qian ◽  
Xuesen Zeng ◽  
Tao Hua
Keyword(s):  
Analytical Model ◽  
Cfd Simulation ◽  
Cell Model ◽  
Rectangular Cross Section ◽  
Air Flow ◽  
Sensitivity Study ◽  
Unit Cell ◽  
Air Pressure ◽  
Woven Fabric ◽  
Duct Wall

Many technical applications of woven fabric are subject to increasing high pressure from air transport through the fabric. The through-thickness permeability (TP) of woven materials exhibits a dynamic response to increased air pressure. This paper presents an analytical model for predicting the steady TP of woven fabric. The approach was based on Darcy’s law and the Poiseuille equation, using the flow boundary of an idealized plain-weave unit cell. The unit cell model consists of a gradual converging-diverging (GCD) duct with a rectangular cross-section. Further, the dynamic TP of the GCD duct was established analytically as a function of increasing pressure, which correlates to the separation of air flow from the GCD duct wall. Air flow separation from the duct wall led to a quadratic relationship between the increasing pressure and air flow velocities. This dynamic TP and air flow nonlinearity were simulated numerically in the computational fluid dynamics solver CFX. Five GCD ducts under increasing air pressure were analyzed numerically and analytically. The comparison showed good agreement between the proposed analytical model and the CFD simulation, with a maximum error up to 12%. A sensitivity study showed that an increase in porosity or a decrease in the thickness of weave materials could result in a larger dynamic TP value.

scholarly journals Experimental Study on Atomization of Plain Jet Injector Under High Pressure Co-Axial Air Flow

1987 ◽  
Author(s):  
Gui Xiang Yang ◽  
J. S. Chin
Keyword(s):  
Experimental Study ◽  
High Velocity ◽  
Drop Size ◽  
Air Flow ◽  
Test Chamber ◽  
Back Pressure ◽  
Air Pressure ◽  
Working Fluid ◽  
Air Velocity ◽  
Pressure Drops

An experimental study has been conducted on the effect of high back pressure on the spray characteristics of a plain jet injector under coaxial high velocity air flow. The air pressures tested range from 1 to 16 atm, the range of air velocity is 60–120 m/s, the pressure drops of injector tested are 200–2000 kpa. Working fluid is water. Injector hole diameter is 0.5 mm. The key feature of the experiment is using a convergent-divergent nozzle to maintain a high air pressure inthe test chamber and at the same time to maintain a high velocity air flow in the atomization zone. Such an experimental arrangement totally eliminates air and droplets recirculation in the test chamber and problem related to slow droplet settling in a commonly used pressurized vessel for high back pressure atomization research. The results show that SMD decreases monotonicly with the increase of back pressure or air velocity, at different air velocities, the effect of air pressure is different. The drop size distribution parameter N in Rosin-Rammler distribution decreases slightly with increase of back pressure or air velocity.

scholarly journals DISTRIBUSI TEMPORAL DAN SPASIAL TEKANAN UDARA TERKAIT PERTUMBUHAN AWAN DI DAS LARONA, SULAWESI SELATAN

2011 ◽  
Vol 12 (2) ◽  
pp. 55
Author(s):  
Tri Handoko Seto
Keyword(s):  
Data Analysis ◽  
Spatial Data ◽  
Air Flow ◽  
Air Pressure ◽  
Rainfall Data ◽  
Spatial Data Analysis ◽  
Weather Modification ◽  
Air Mass ◽  
Strong Growth ◽  
South Sulawesi

Telah dilakukan análisis temporal dan spasial data tekanan udara dan curah hujan menggunakan data hasil pengukuran dengan AWS dan penakar hujan manual di DASLarona, Sulawesi Selatan. Dari hasil analisis temporal nampak bahwa tekanan udarapermukaan cenderung turun saat pertumbuhan awan. Penurunan tekanan menjadi energi yang digunakan untuk menarik massa udara di sekitarnya. Ketika terjadi hujan maka tekanan udara menjadi tinggi akibat adanya pendinginan masa udara. Dari analisisspasial nampak bahwa daerah yang memiliki tekanan lebih rendah cenderung memilikicurah hujan yang lebih tinggi dibandingkan dengan daerah-daerah di sekitarnya. Hasilpenelitian ini bisa dijadikan referensi bahwa ketika terjadi pertumbuhan awan di suatulokasi maka aliran udara akan masuk menuju lokasi pertumbuhan awan. Semakin kuat pertumbuhan awannya maka semakin kuat tarikan massa udara dari sekitarnya. Dalam teknologi modifikasi cuaca, usaha memperkuat pertumbuhan awan mungkin bisa dijadikan salah satu strategi untuk menarik massa udara atau awan-awan yang lebih kecil ke area dengan pertumbuhan awan yang kuat. Namun masih perlu dilakukan penelitian lebih lanjut untuk membuktikan hipotesa ini.Temporal and spatial data analysis of air pressure and rainfall data using AWS andrain gauges in the watershed of Larona, South Sulawesi has been done. From theresults it appears that surface air pressure tends to fall when clouds develop. Pressuredecreasing became energy which is used to draw air mass from the vicinity. When itrains then the air pressure increased due to the cooling of the air. From the spatialanalysis it appears that areas with lower pressure tend to have higher rainfall than thesurrounding areas. The results of this study can be used as a reference that when thereis cloud growth in a location, air flow will go to the location of cloud growth. The stronger cloud’s growth the stronger pull of the surrounding air mass. In weather modification technology, strengthen the growth of cloud technique may be used as one strategy to attract the mass of air or clouds of smaller clouds to the area with strong growth. But it still needs to do further research to prove this hypothesis.

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