Computational aeroacoustics of phonation: Effect of subglottal pressure, glottal oscillation frequency, and ventricular folds

2001 ◽  
Vol 109 (5) ◽  
pp. 2412-2412 ◽  
Author(s):  
Cheng Zhang ◽  
Wei Zhao ◽  
Steven H. Frankel ◽  
Luc Mongeau
Keyword(s):  
Oscillation Frequency ◽  
Computational Aeroacoustics ◽  
Subglottal Pressure ◽  
Ventricular Folds

Computational aeroacoustics of phonation, Part II: Effects of flow parameters and ventricular folds

2002 ◽  
Vol 112 (5) ◽  
pp. 2147-2154 ◽  
Author(s):  
Cheng Zhang ◽  
Wei Zhao ◽  
Steven H. Frankel ◽  
Luc Mongeau
Keyword(s):  
Computational Aeroacoustics ◽  
Flow Parameters ◽  
Ventricular Folds

Signal Interpretation Considerations When Estimating Subglottal Pressure From Oral Air Pressure

2019 ◽  
Vol 62 (5) ◽  
pp. 1326-1337 ◽  
Author(s):  
Brittany L. Perrine ◽  
Ronald C. Scherer ◽  
Jason A. Whitfield
Keyword(s):  
Standard Condition ◽  
Word Production ◽  
Air Pressure ◽  
Pressure Waveform ◽  
Pressure Measurements ◽  
Air Leak ◽  
Pressure Signal ◽  
Adult Participants ◽  
Syllable Repetition ◽  
Subglottal Pressure

Purpose Oral air pressure measurements during lip occlusion for /pVpV/ syllable strings are used to estimate subglottal pressure during the vowel. Accuracy of this method relies on smoothly produced syllable repetitions. The purpose of this study was to investigate the oral air pressure waveform during the /p/ lip occlusions and propose physiological explanations for nonflat shapes. Method Ten adult participants were trained to produce the “standard condition” and were instructed to produce nonstandard tasks. Results from 8 participants are included. The standard condition required participants to produce /pːiːpːiː.../ syllables smoothly at approximately 1.5 syllables/s. The nonstandard tasks included an air leak between the lips, faster syllable repetition rates, an initial voiced consonant, and 2-syllable word productions. Results Eleven oral air pressure waveform shapes were identified during the lip occlusions, and plausible physiological explanations for each shape are provided based on the tasks in which they occurred. Training the use of the standard condition, the initial voice consonant condition, and the 2-syllable word production increased the likelihood of rectangular oral air pressure waveform shapes. Increasing the rate beyond 1.5 syllables/s improved the probability of producing rectangular oral air pressure signal shapes in some participants. Conclusions Visual and verbal feedback improved the likelihood of producing rectangular oral air pressure signal shapes. The physiological explanations of variations in the oral air pressure waveform shape may provide direction to the clinician or researcher when providing feedback to increase the accuracy of estimating subglottal pressure from oral air pressure.

Aerodynamic and Acoustic Voice Measures Before and After an Acute Public Speaking Stressor

2020 ◽  
Vol 63 (10) ◽  
pp. 3311-3325
Author(s):  
Brittany L. Perrine ◽  
Ronald C. Scherer
Keyword(s):  
Fundamental Frequency ◽  
Salivary Cortisol ◽  
Public Speaking ◽  
Stress System ◽  
Before And After ◽  
Subglottal Pressure ◽  
Response To Stress ◽  
System Activation ◽  
Speaking Fundamental Frequency ◽  
Pituitary Adrenal Axis

Purpose The goal of this study was to determine if differences in stress system activation lead to changes in speaking fundamental frequency, average oral airflow, and estimated subglottal pressure before and after an acute, psychosocial stressor. Method Eighteen vocally healthy adult females experienced the Trier Social Stress Test (TSST) to activate the hypothalamic–pituitary–adrenal axis. The TSST includes public speaking and performing mental arithmetic in front of an audience. At seven time points, three before the stressor and four after the stressor, the participants produced /pa/ repetitions, read the Rainbow Passage, and provided a saliva sample. Measures included (a) salivary cortisol level, (b) oral airflow, (c) estimated subglottal pressure, and (d) speaking fundamental frequency from the second sentence of the Rainbow Passage. Results Ten of the 18 participants experienced a hypothalamic–pituitary–adrenal axis response to stress as indicated by a 2.5-nmol/L increase in salivary cortisol from before the TSST to after the TSST. Those who experienced a response to stress had a significantly higher speaking fundamental frequency before and immediately after the stressor than later after the stressor. No other variable varied significantly due to the stressor. Conclusions This study suggests that the idiosyncratic and inconsistent voice changes reported in the literature may be explained by differences in stress system activation. In addition, laryngeal aerodynamic measures appear resilient to changes due to acute stress. Further work is needed to examine the influence of other stress systems and if these findings hold for dysphonic individuals.

Effect of yaw on pressure oscillation frequency within rectangular cavity at Mach 2

AIAA Journal ◽  
1997 ◽  
Vol 35 ◽  
pp. 1233-1235 ◽  
Author(s):  
Peter J. Disimile ◽  
Paul D. Orkwis
Keyword(s):  
Oscillation Frequency ◽  
Pressure Oscillation ◽  
Rectangular Cavity

scholarly journals A Novel 4H-SiC MESFET with a Heavily Doped Region, a Lightly Doped Region and an Insulated Region

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 488
Author(s):  
Hujun Jia ◽  
Mengyu Dong ◽  
Xiaowei Wang ◽  
Shunwei Zhu ◽  
Yintang Yang
Keyword(s):  
Breakdown Voltage ◽  
Direct Current ◽  
Oscillation Frequency ◽  
The Novel ◽  
Saturation Current ◽  
Excellent Performance ◽  
Maximum Oscillation Frequency ◽  
Power Added Efficiency ◽  
Novel Structure ◽  
Heavily Doped

A novel 4H-SiC MESFET was presented, and its direct current (DC), alternating current (AC) characteristics and power added efficiency (PAE) were studied. The novel structure improves the saturation current (Idsat) and transconductance (gm) by adding a heavily doped region, reduces the gate-source capacitance (Cgs) by adding a lightly doped region and improves the breakdown voltage (Vb) by embedding an insulated region (Si3N4). Compared to the double-recessed (DR) structure, the saturation current, the transconductance, the breakdown voltage, the maximum oscillation frequency (fmax), the maximum power added efficiency and the maximum theoretical output power density (Pmax) of the novel structure is increased by 24%, 21%, 9%, 11%, 14% and 34%, respectively. Therefore, the novel structure has excellent performance and has a broader application prospect than the double recessed structure.

scholarly journals Search for intermittent X-ray pulsations from neutron stars in low-mass X-ray binaries

2021 ◽  
Vol 38 ◽  
Author(s):  
Yunus Emre Bahar ◽  
Manoneeta Chakraborty ◽  
Ersin Göğüş
Keyword(s):  
Neutron Stars ◽  
Orbital Period ◽  
Oscillation Frequency ◽  
Orbital Motion ◽  
X Rays ◽  
X Ray ◽  
Second Stage ◽  
Corrected Data ◽  
Low Mass ◽  
X Ray Binaries

Abstract We present the results of our extensive binary orbital motion corrected pulsation search for 13 low-mass X-ray binaries. These selected sources exhibit burst oscillations in X-rays with frequencies ranging from 45 to 1 122 Hz and have a binary orbital period varying from 2.1 to 18.9 h. We first determined episodes that contain weak pulsations around the burst oscillation frequency by searching all archival Rossi X-ray Timing Explorer data of these sources. Then, we applied Doppler corrections to these pulsation episodes to discard the smearing effect of the binary orbital motion and searched for recovered pulsations at the second stage. Here we report 75 pulsation episodes that contain weak but coherent pulsations around the burst oscillation frequency. Furthermore, we report eight new episodes that show relatively strong pulsations in the binary orbital motion corrected data.

Free particle oscillation frequency in an isochronous cyclotron as affected by space charge

1963 ◽  
Vol 15 (3) ◽  
pp. 906-911
Author(s):  
A. A. Glazov ◽  
V. P. Dzhelepov ◽  
V. P. Dmitrievskii ◽  
B. I. Zamolodchikov ◽  
V. V. Kol'ga ◽  
...  
Keyword(s):  
Space Charge ◽  
Oscillation Frequency ◽  
Free Particle ◽  
Isochronous Cyclotron
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