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Results 301 - 350 of 1064
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Babisch Wolfgang - - 2008
The HYENA study is a multi-centred study regarding the effects of aircraft noise and road traffic noise on blood pressure (BP) which was funded by the European Community. Study subjects were 4,861 males and females aged between 45 and 70 years, who had lived for at least 5 years in ...
Fuchs Susanne - - 2008
Intraoral pressure changes during speech production are a result of different factors, such as articulatory movements (place and manner of articulation), subglottal pressure, and laryngeal-oral coordination. This study attempts to provide a better understanding of the relation between aerodynamics and articulation in single voiceless consonants and their combinations. We gathered ...
Tayong Rostand - - 2008
When submitted to relatively high sound pressure amplitudes, Micro Perforated Panels (MPP) are influenced by certain effects, which are non negligible (vibration of the panel, end radiation and also proximity of the perforations). A model of the total impedance of the MPP is derived from the sum of the contributions ...
Stevenson Samuel - - 2008
It is widely accepted that the starting transient is an extremely significant perceptual feature of musical sound. For players, the ease with which a note can be started on a particular instrument is also of great importance. However, until recently research has concentrated on the analysis of steady state sounds ...
Santin Mathieu - - 2008
Dilute solutions of Optison and Definity were studied using a passive cavitation detector (PCD) with a 2.8-MHz transmitter and 13-MHz receiver. The dilution was such that each received signal should, on average, arise from a single microbubble. Several hundred microbubble responses were acquired at each of three rarefactional pressures (1.6+-0.2, ...
Daridon Jean Luc - - 2008
The thermophysical properties of pure substances in fluid state as functions of temperature and pressure are of great interest not only for industrial applications (for example in the oil and gas industry), but also for fundamental aspects in view of developing models for an accurate representation of dense fluids. Now ...
Horodysky Andrij Z - - 2008
Sciaenid fishes are important models of fish sound production, but investigations into their auditory abilities are limited to acoustic pressure measurements on five species. In this study, we used auditory brainstem response (ABR) to assess the pressure and particle acceleration thresholds of six sciaenid fishes commonly found in Chesapeake Bay, ...
Horvat Marko - - 2008
As a part of an extensive ongoing research on reverberation time measurements, efforts have been made to find an impulse-like source that will comply with certain demands concerning its spectral content and sound pressure levels it can provide. Although the relevant standards state that such kind of sources should be ...
Koga Yuichiro - - 2008
We propose a method for analysing of the acoustic characteristics of compact acoustic reproduction systems with Three-Dimensional FDTD method. We reproduce actual structure of compact acoustic reproduction systems and take the frequency characteristic of sound pressure level at a point with Three-Dimensional FDTD method. To compare the frequency characteristic of ...
Bader Rolf - - 2008
The vibration of a reed of a saxophone is calculated using a 2D model of the mouth cavity, the mouth piece and the reed. The time-dependent Finite-Element calculation takes the flow-structure interaction into account and changes the geometry of the flow according to the reed vibration in time. The model ...
Paulsen Reimer - - 2008
The degree to which employees on construction sites are exposed to noise often depends on a variety of individual activities. The calculation of the average noise exposure for different construction trades in this sector calls for an enhanced level of work analysis and measurement. Recommended here are personal measurements with ...
Ljunggren Fredrik - - 2008
This paper relates to building acoustic measurement inside a two-story office house. The construction, which is known as lightweight, is prefabricated in volumes at a factory and is then transported to the building yard for assembling. It is build up of a wooden frame with particle boards and plaster boards ...
Fulcher Lewis P - - 2008
Pressure distributions were obtained with a static physical model (M5) at diameters d = 0.005, 0.01, 0.02, 0.04, 0.08, 0.16, and 0.32 cm for converging angles of 5, 10, 20, and 40 degrees. At each diameter and angle, transglottal pressures typically ranged from 3 to 15 cm H(2)O. For each ...
Van Renterghem Timothy - - 2008
In this paper, the finite-difference time-domain method is used to study sound propagation over a green roof in an urban situation. Sound propagation between adjacent city canyons is considered, and the focus is on the reduction of the sound pressure level in the non-exposed canyon due to the presence of ...
Baldwin Ann Linda - - 2008
OBJECTIVES: To determine whether application of Reiki to noise-stressed rats can reduce their heart rates (HRs) and blood pressures. RATIONALE: In a previous study, we showed that exposure of rats to 90 dB white noise for 15 minutes caused their HRs and blood pressures to significantly increase. Reiki has been ...
Koenig Laura L - - 2008
Phonation requires that tracheal pressure remain higher than intraoral pressure (Pio). In obstruent consonants, a major constriction in the upper vocal tract yields an increase in Pio, inhibiting phonation. The degree of Pio increase in consonants varies as a function of laryngeal and supraglottal apertures. Voiceless stops involve a rapid ...
Raghukumar Kaustubha - - 2008
A first-order Born approximation is used to obtain the pressure sensitivity of the received signal to small changes in medium sound speed. The pressure perturbation to the received signal caused by medium sound speed changes is expressed as a linear combination of single-frequency sensitivity kernels weighted by the source signal ...
Henrich Nathalie - - 2008
In lyrical singing, two principal laryngeal mechanisms are used to produce all the notes across the singer's tessitura. Laryngeal mechanisms M1 and M2 are characterised by a greater and lesser vibrating mass respectively. Different timbres between the two are at least partly explained by their different glottal behaviours. However, different ...
Park Jong Beom - - 2008
The glottal displacement flow is a volume flow induced by the motion of the vocal folds in the absence of transglottal pressure. This source may eventually contribute to the radiated sound, in particular during glottal opening. The volume source strength was numerically computed for a time-varying rigid M5 geometry, and ...
Ryherd Steve - - 2008
The purpose of this project was to investigate the effects of the wearer's voice as a dominant sound source on body-mounted noise dosimeters in medium-level acoustic environments. Noise dosimeters provide a convenient method of quantifying an occupant's acoustical exposure. In recent years, interest in personal noise exposure has expanded beyond ...
Kragh Jorgen - - 2008
In 1999 three different types of two-layer porous asphalt pavement with 5 mm or 8 mm maximum aggregate in the top layer were built in a city street in Copenhagen. A section with dense asphalt concrete was built as a reference. The pavements have been monitored since then. The initial ...
Lucero Jorge C - - 2008
Several past studies have used laryngeal andor upper vocal tract models to explore aerodynamic control during production of obstruent consonants, yet many aspects of such control remain unclear. Of particular interest in this work is how varying laryngeal and vocal tract dimensions such as occur among men, women, and children ...
Rosenkrantz Eric - - 2008
The impedance of gas contained between two plane walls is a periodic function of the frequency. The frequency interval between two resonances of the gas is equal to c2D. Furthermore, the amplitude of the resonances is proportional to the pressure. We describe a signal processing to easily deduce the speed ...
Barney Anna - - 2008
During voiced speech the source of sound production arises from the vibrations of the vocal folds within the larynx. In order to terminate these vibrations it is necessary either to adduct the vocal folds to produce a forced closure or to reduce the pressure drop across them to below a ...
Borucki Sebastian - - 2008
The subject matter of the research work presented in this paper refers to the measurements of the values of the acoustic pressure levels (noise) occurring around a main feeding-point aerial substation adjacent to apartment buildings. The paper presents the values of the noise accompanying the particular power devices, mainly transformers, ...
Lucero Jorge C - - 2008
The dynamical principles of the vocal fold oscillation at phonation were set forth by Titze (I. R. Titze, J. Acoust. Soc. Am. 83, 1536-1552 , 1988), by representing motion of the tissues as a surface wave propagating in the direction of the airflow. An important result of his work was ...
Schmidt Sebastian - - 2008
Equal-loudness contours represent the relationship of loudness perception and sound pressure at the ear. Usually, the reference pressure is defined with a standardised calibration procedure. Individual ear canal characteristics significantly influence the contours, resulting in peaks and notches. By choosing the eardrum pressure as reference for the perception measurements, individual ...
Bailly Lucie - - 2008
Period-doubling occurrences have been found during singing phonations such as Mongolian Kargyraa throat singing or Sardinian A Tenore Bassu singing. The combined vibrations of vocal folds and ventricular bands have been observed during the production of such low-pitch bass-type sounds. The present study aims at better understanding the physical interaction ...
Lee Pyoung Jik - - 2008
A procedure to convert the floor impact sound level of the bang machine as well as the tapping machine into that of the impact ball was suggested. Because the bang machine has been the only standard heavy-weight impact source for a long time in Japan and Korea, much of its ...
Honda Kiyoshi - - 2008
In the production of voiceless fricatives, the airflow passing through the vocal tract is controlled by reciprocal open-close patterns of the glottal and oral constriction. In order to observe such coordinated patterns, the authors have developed a combined method using a non-invasive (external-lighting and sensing) photoglottographic (ePGG) technique and a ...
Nakamura Toshiaki - - 2008
In this paper, we describe the characteristics of an acoustic aplanat lens which can eliminate both spherical and coma aberrations. A singlet aplanat lens was designed using a ray theory in paraxial area. Sound pressure fields of the bi-concave aplanat lens and a spherical lens with 160 mm in diameter ...
Cheenne Dominique J - - 2008
Anechoic recordings of balloon bursts were systematically acquired for various conditions of balloon diameters, puncture location, and inflation pressure. The recordings were analyzed to derive the average frequency spectrum over the effective duration of the acoustic impulse. Although the data show the well-known limitations for the impulse responses (in terms ...
Blake William - - 2008
Sound produced by turbulent-boundary layers (TBL) over rough walls is being studied in a series of physical-computational experiments. At issue is the development of a knowledge of how the wall elements generate flow dipoles which directly determines how the sound is described in terms of dependent variables. The considered mechanisms ...
Guedel Alain - - 2008
Broadband noise is a major part of the noise radiated by low-speed fans such as industrial and domestic fans. One of the main mechanisms of broadband noise is blade trailing-edge noise, which is due to the convection of the turbulent flow of the boundary layer past the blade trailing edge. ...
Scherer Ronald C - - 2008
Asymmetric vocal fold oscillation occurs for both normal and pathological phonation. The pressures on the right and left glottal walls receive different pressures when the glottis is oblique, as we have shown previously. Different driving forces may affect the motion, although to what extent is not yet known. We have ...
Czerwonka Lukasz - - 2008
HYPOTHESIS: Vocal fold vibration may physically raise intravascular pressure to levels high enough to damage capillaries and result in leakage of erythrocytes. This type of injury is commonly seen in benign vocal fold lesions and is not well explained. STUDY DESIGN: Theoretical, retrospective. METHODS: The relationship of intravascular pressure to ...
Mellow Tim - - 2008
Radiation characteristics are calculated for a circular planar sound source in free space with a uniform surface pressure distribution, which can be regarded as a freely suspended membrane with zero mass and stiffness. This idealized dipole source is shown to have closed form solutions for its far-field pressure response and ...
Foo Jong Yong A - - 2008
OBJECTIVES: Vascular transit time (VTT) can be defined as the first heart sound of the phonocardiography (PCG) signal to its arrival at the photoplethysmography (PPG). Studies have shown that monitoring VTT can be useful as an early prognosis of cardiac diseases. However, there is limited study conducted to understand the ...
Ahlstrom C - - 2008
We have previously developed a method for localization of the first heart sound (S1) using wavelet denoising and ECG-gated peak-picking. In this study, an additional enhancement step based on cross-correlation and ECG-gated ensemble averaging (EA) is presented. The main objective of the improved method was to localize S1 with very ...
Tao Chao - - 2008
The effect of the pressure recovery at glottal exit is introduced to modify the one-mass model. Using the modified one-mass model, the phonation critical condition, including phonation threshold pressure and phonation threshold flow, is analyzed by using the small-amplitude oscillation theory. It is found that the phonation threshold pressure is ...
McNamar Justin - - 2008
HYPOTHESIS: Adduction arytenopexy (AP) with thyroplasty provides improved physiologic placement of the vocal fold and therefore provides improved acoustic, aerodynamic, and vibratory function as compared with arytenoid adduction (AA) with thyroplasty. METHODS: Five cadaveric human larynges were prepared by removing supraglottic tissues and fixing the nontest vocal fold medially on ...
Tsiou Chrisoula - - 2008
This study is an evaluation of the problem of noise pollution in operating rooms. The high sound pressure level of noise in the operating theatre has a negative impact on communication between operating room personnel. The research took place at nine Greek public hospitals with more than 400 beds. The ...
Koenig Laura L - - 2008
Previous authors have established that stop consonant voicing is more limited in young children than adults, and have ascribed this to immature vocal-tract pressure management. Physical development relevant to speech aerodynamics continues into adolescence, suggesting that consonant voicing development may also persist into the school-age years. This study explored the ...
Decremps F - - 2008
We report an innovative high pressure method combining the diamond anvil cell device with the technique of picosecond ultrasonics. Such an approach allows us to measure sound velocity and attenuation of solids and liquids under pressure of tens of GPa, overcoming all the drawbacks of traditional techniques. The power of ...
Koenig Laura L - - 2008
The aim of this within-speaker case study was to explore how effectively a phonetically trained speaker could alter the likelihood of voicing around abduction, and what changes he made to do so. An American English-speaking male produced intervocalic /h/ in varying loudness and vowel contexts. When given no specific instructions ...
Choi Hyun-Seok - - 2008
In this paper, a new noise reduction method was proposed for oscillometric blood pressure measurement. The proposed method uses a capacitive sensor and an adaptive filter to minimize blood pressure measurement error. Noise such as undesired external pressure applied to cuff was focused on. Three types of the distorted oscillation ...
Carter Calvin - - 2008
Binaural beats are the differences in two different frequencies (in the range of 30-1000 Hz). Binaural beats are played through headphones and are perceived by the superior olivary nucleus of each hemisphere of the brain. The brain perceives the binaural beat and resonates to its frequency (frequency following response). Once ...
Harvey Margaret B - - 2008
T wave alternans (TWA) is a marker of ventricular electrical instability considered to be predictive for ventricular tachyarrhythmias. Techniques have been developed to detect TWA at the microv level as a method for arrhythmia risk stratification of persons at high risk for sudden cardiac death. Currently, TWA is typically calculated ...
Plummer Emily Megan - - 2008
Song of the zebra finch (Taeniopygia guttata) is a complex temporal sequence generated by a drastic change to the regular oscillations of the normal respiratory pattern. It is not known how respiratory functions, such as supply of air volume and gas exchange, are controlled during song. To understand the integration ...
Bombardini Tonino - - 2008
Recently, a cutaneous force-frequency relation recording system based on first heart sound amplitude vibrations has been validated. A further application is the assessment of Second Heart Sound (S2) amplitude variations at increasing heart rates. The aim of this study was to assess the relationship between second heart sound amplitude variations ...
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