The aerodynamic transfer of energy from glottal airflow to vocal fold tissue during phonation was explored using complementary synthetic and numerical models. model fabricated a flexible polyurethane rubber compound. size, shape, material properties were generally similar corresponding human characteristics. Regular, self-sustained oscillations achieved at frequency approximately 120 Hz. onset pressure 1.2 kPa. A two-dimensional finite element developed geometry definitions based on the...

The flow-induced responses of four self-oscillating synthetic vocal fold models are compared. All were life-sized and fabricated using flexible silicone compounds with material properties comparable to those human tissue. Three the had two layers different stiffness represent body-cover grouping Two two-layer based on "M5" geometry [Scherer et al., J. Acoust. Soc. Am. 109, 1616-1630 (2001)], while third was magnetic resonance imaging data. fourth model included several layers, including a...

Striking the top of a liquid-filled bottle can shatter bottom. An intuitive interpretation this event might label an impulsive force as culprit in fracturing phenomenon. However, high-speed photography reveals formation and collapse tiny bubbles near bottom before fracture. This observation indicates that damaging phenomenon cavitation is at fault. Cavitation well known for causing damage various applications including pipes ship propellers, making accurate prediction onset vital several...

The unique avian vocal organ, the syrinx, is located at caudal end of trachea. Although a larynx also present opposite end, birds phonate only with syrinx. Why evolved novel sound source this location remains unknown, and hypotheses about its origin are largely untested. Here, we test hypothesis that syrinx constitutes biomechanical advantage for production over combined theoretical experimental approaches. We investigated whether position within respiratory tract affects acoustic features...

A synthetic two-layer, self-oscillating, life-size vocal fold model was used to study the influence of tract and false folds on glottal jet. The vibrated at frequencies, pressures, flow rates, amplitudes consistent with human phonation, although some differences in behavior between are noted. High-speed images motion visualization were acquired. Phase-locked ensemble-averaged jet velocity measurements using particle image velocimetry (PIV) acquired without an idealized tract, folds. PIV data...

Cavities branching off the main vocal tract are ubiquitous in nonhumans. Mammalian air sacs exist human relatives, including all four great apes, but only a substantially reduced version exists humans. The present paper focuses on acoustical functions of sacs. hypotheses investigated whether affect amplitude utterances and/or position formants. A multilayer synthetic model folds coupled with was utilized. As an sac model, configurations were considered: open and closed uniform tube-like side...

Obtaining pressure field data from particle image velocimetry (PIV) is an attractive technique in fluid dynamics due to its noninvasive nature. The application of this generally involves integrating the gradient or solving Poisson equation using a velocity measured with PIV. However, very little research has been done investigate error propagation PIV-based measurements calculation. Rather than measure through experiment, we by examining directly. We analytically quantify bound field, and...

This study investigates the impact of subglottic stenosis (SGS) on voice production using a subject-specific laryngeal and airway model. Direct numerical simulations fluid–structure–acoustic interaction were employed to analyze glottal flow dynamics, vocal fold vibration, acoustics under realistic conditions. The model accurately captured key physiological parameters, including rate, vibration patterns, first four formant frequencies. Simulations varying SGS severity revealed that up 75%...

The process of human phonation involves a complex interaction between the physical domains structural dynamics, fluid flow, and acoustic sound production radiation. Given high degree nonlinearity these processes, even small anatomical or physiological disturbances can significantly affect voice signal. In worst cases, patients lose their hence normal mode speech communication. To improve medical therapies surgical techniques it is very important to understand better physics process. Due...

Recent vocal fold vibration studies have used models defined using idealized geometry. Although these exhibit important similarities with human vibration, some aspects of their motion are less than realistic. In this report it is demonstrated that more realistic may be obtained when geometry derived from magnetic resonance imaging (MRI) data. The dynamic response both and MRI-based synthetic presented. model improvements include evidence mucosal wave-like vertical movement. Limitations the...

Sound for the human voice is produced via flow-induced vocal fold vibration. The folds consist of several layers tissue, each with differing material properties 1. Normal production relies on healthy tissue and folds, occurs as a result complex coupling between aerodynamic, structural dynamic, acoustic physical phenomena. Voice disorders affect up to 7.5 million annually in United States alone 2 often significant financial, social, other quality-of-life difficulties. Understanding physics...

The human vocal folds (VFs) undergo complex biomechanical stimulation during phonation. aim of the present study was to develop and validate a phono-mimetic VF flow perfusion bioreactor, which mimics mechanical microenvironment VFs in vitro. bioreactor uses airflow-induced self-oscillations, have been shown produce loading contact forces that are representative consisted two synthetic replicas within silicone body. A cell-scaffold mixture (CSM) consisting fibroblasts, hyaluronic acid,...

Although the signature of human voice is mostly tonal, it also includes a significant broadband component. Quadrupolelike sources due to turbulence in region downstream glottis, and dipolelike force applied by vocal folds onto surrounding fluid are two primary sound generating mechanisms. In this study, experiments were conducted characterize emissions confined stationary jets through rubber orifices formed imitate approximate shape glottis at different stages during one cycle fold...

Flapping flight has the potential to revolutionize micro air vehicles (MAVs) due increased aerodynamic performance, improved maneuverability, and hover capabilities. This paper presents design of a robotic flapping wing mechanism for use in general studies involving laboratory-based experimental optimization trajectories. The allows dynamic adjustment trajectories or liquids with three rotational degrees freedom on each wing. design, instrumentation, control are discussed, characterization...

Simplified models have been used to simulate and study the flow-induced vibrations of human vocal folds. While it is clear that models' responses are sensitive geometry, not how what extent specific geometric features influence model motion. In this played significant roles in governing motion a two-layer (body-cover), two-dimensional, finite element fold were identified. The was defined using flow solver based on viscous, unsteady, Navier-Stokes equations solid allowed for large strain...

Abstract Since 2004 Southwestern Energy (SWN) has completed more than 2,000 wells in the Fayetteville shale with thousands of remaining to be drilled and completed. The is a world-class play stretching across central Arkansas that encompasses 2-million acres. Current SWN gross daily operated production 1.9 BCF/D at December 31, 2010 its proved net reserves booked were 4.3 TCF. This paper will discuss progression completions from beginning their current best practices. It review different...

Images of a water-filled bottle fracturing after the collapse cavitation bubble (5000 Hz frame rate).The event is caused by an initial impact with top accelerometer-instrumented bottle.Images are synchronized accelerometer data (50 kHz) and corresponding growth, collapse, fracture events indicated dashed red lines on plot.Shaded regions refer to events.

Geometry of the human vocal folds strongly influences their oscillatory motion. While effect intraglottal geometry on phonation has been widely investigated, study inferior surface limited. In this way in which fold angle affects vibration was explored using a two-dimensional, self-oscillating finite element model. The parameterized to create models with five different angles. Four exhibited self-sustained oscillations. Comparisons model motion showed increased vertical displacement and...