An analysis of the mechanics of phonation

1965 ◽  
Vol 20 (2) ◽  
pp. 301-307 ◽  
Author(s):  
G. A. Cavagna ◽  
R. Margaria
Keyword(s):  
Sound Production ◽  
Respiratory Muscles ◽  
Sound Intensity ◽  
Sound Level ◽  
Intensity Level ◽  
Elastic Recoil ◽  
Mechanical Models ◽  
Fine Regulation ◽  
Flow Through ◽  
Work Done

The mechanical work done by the chest in phonation has been measured together with the sound intensity level. The regulation of the sound intensity is done by regulating the intrapulmonary pressure. This is achieved at high intensity levels through the activity of the respiratory muscles that, together with the elastic recoil of the chest, sustain the work of phonation. At sound intensities below a critical level an additional mechanism for changing the intensity is given by a fine regulation of the opening of the glottis, thus allowing more air to escape without contributing to sound production. The contribution of the respiratory muscles, of the chest elasticity, and of the opening of the glottis to phonation at different intensity levels depend on the degree of inflation of the chest. The efficiency of phonation, as of sound production in mechanical models, seems to increase with increasing intensity and pitch. voice production; work done by chest during phonation; mechanical models of glottis generator; subglottic pressure as a function of sound level; air flow through glottis during phonation; efficiency changes of sound production; variation of sound intensity by regulating opening of glottis; variations of the area of glottis depending on extent of elastic recoil of chest Submitted on February 10, 1964

Acoustics of Sound Production and of Hearing in the Bladder Cicada Cystosoma Saundersii (Westwood)

1978 ◽  
Vol 72 (1) ◽  
pp. 43-55 ◽  
Author(s):  
N.H. FLETCHER ◽  
K. G. HILL
Keyword(s):  
Sound Production ◽  
Abdominal Cavity ◽  
Low Frequency ◽  
Sound Intensity ◽  
Electrical Network ◽  
Directional Hearing ◽  
Hearing Sensitivity ◽  
Physical Mechanisms ◽  
Radiated Sound ◽  
Song Frequency

The male cicada of the species Cystosoma saundersii has a grossly enlarged, hollow abdomen and emits a loud calling song with a fundamental frequency of about 800 Hz. At the song frequency, its hearing is nondirectional. The female of C. saundersii lacks sound producing organs, has no enlargement of the abdomen, but possesses an abdominal air sac and has well developed directional hearing at the frequency of the species' song. Physical mechanisms are proposed that explain these observations in semi-quantitative detail using the standard method of electrical network analogues. The abdomen in the male, with its enclosed air, is found to act as a system resonant at the song frequency, thus contributing a large gain in radiated sound intensity. Coupling between this resonator and the auditory tympana accounts for the observed hearing sensitivity in the male, but destroys directionality. In the female, the abdominal cavity acts in association with the two auditory tympana as part of a phase shift network which results in appreciable directionality of hearing at the unusually low frequency of the male song.

scholarly journals Analysis of Angklung Sound Intensity as a Acoustic Instrument

2017 ◽  
Vol 2 (1) ◽  
pp. 122 ◽  
Author(s):  
Rizka Silviana Hartanti ◽  
Budi Astuti
Keyword(s):  
Research Method ◽  
Sound Intensity ◽  
Sound Level ◽  
Tube Length ◽  
High Tone ◽  
Sound Level Meter ◽  
Independent Variable ◽  
Constant Distance ◽  
Low Tone ◽  
Level Meter

<p style="text-align: justify;">The purpose of this study was to analysis of angklung sound intensity. The research method is using angklung musician 2 octaves. Each consists of two tube tone that sounded from the tone of G to G ', length and diameter of the tube every tone becomes independent variable, while intensity of the sound produced becomes dependent variable. Sound intensity is measured using a Sound Level Meter is placed with a constant distance. The result showed that G tone was a low tone which had a frequency of 49.5 Hz, first tube had 21.6 cm length and 4.1 cm diameter, second tube had 10.1 cm length and 3.4 cm diameter produced the sound intensity of 90.7 dB. G’ tone was a high tone which had a frequency of 99 Hz, first tube had 10 cm length and 3 cm diameter, second tube had 5.5 cm length and 2.1 cm diameter produced the sound intensity of 99.1 dB. It can be concluded that the higher the frequency, the greater the intensity of the sound produced. The shorter tube length and the smaller tube diameter, the greater the intensity of the sound. ©2016 JNSMR UIN Walisongo. All rights reserved.</p>

Sound emission and the acoustic far field of a singing acridid grasshopper (Omocestus viridulus L.)

1999 ◽  
Vol 202 (12) ◽  
pp. 1571-1577
Author(s):  
A. Michelsen ◽  
N. Elsner
Keyword(s):  
Sound Production ◽  
Sound Intensity ◽  
Movement Pattern ◽  
Forward Direction ◽  
Octave Band ◽  
Sound Emission ◽  
Mean Values ◽  
The Mean ◽  
The One ◽  
Sound Intensities

An array of eight microphones, all at a distance of 15 cm, was used to make simultaneous recordings of the sounds emitted by courting male acridid grasshoppers of the species Omocestus viridulus. In this species, the movement pattern for sound production differs in the two hindlegs, and in most cases the leg facing the female moves with the larger amplitude. The sonic sound intensity (the total sound in the one-third octave bands with centre frequencies from 5 to 20 kHz) is maximal ipsilateral to the leg stridulating with the larger amplitude (the dominant leg). A spontaneous switch of dominance to the other leg may cause a significant change in the emitted sound power. The sound intensities contralateral to the dominant leg and frontal to the animal are, on average, approximately half (−3 dB) of the ipsilateral value, whereas the mean sound intensities behind and above the singer are approximately one-fifth (−7 dB) of the ipsilateral value. In most singers, the patterns of sound radiation are close to these mean values, but in some singers the radiation patterns are radically different. The sound radiated in various directions differs not only in terms of sound intensity but also with respect to the frequency spectrum, which was studied up to the one-third octave band with a centre frequency of 31.5 kHz. In particular, the ratio between the ultrasonic and sonic components is much smaller in the forward direction than in other directions. This may allow the courted female to hear whether the courting male is oriented directly towards her.

Underwater Hearing in the Frog, Rana Catesbeiana

1981 ◽  
Vol 91 (1) ◽  
pp. 57-71 ◽  
Author(s):  
R. ERIC LOMBARD ◽  
RICHARD R. FAY ◽  
YEHUDAH L. WERNER
Keyword(s):  
Sound Pressure ◽  
Rana Catesbeiana ◽  
Sound Intensity ◽  
Torus Semicircularis ◽  
Intensity Level ◽  
Hearing Thresholds ◽  
Average Loss ◽  
Two Measures ◽  
Underwater Hearing ◽  
Hearing Abilities

Comparable auditory sound pressure level (SPL) and sound intensity level(SIL) threshold curves were determined in air and under water in Ranacatesbeiana. Threshold curves were determined using chronic metal electrodeimplants which detected multi-unit responses of the torus semicircularis toincident sound. In terms of SPL, hearing thresholds in water and air aresimilar below 0.2 kHz. Above 0.2 kHz, the sensitivity under water falls of fat about 16 dB/octave to reach an average loss of about 30 dB above 0.4 kHz. In terms of SIL, the organism is about 30 dB more sensitive under water than in air below 0.2 kHz and equally sensitive in air and water above 0.4 kHz.The relative merits of the two measures are discussed and an attempt is made to relate the results to morphology of the middle and inner ears. This report is the first to compare aerial and underwater hearing abilities in any organism using electrode implants.

Reducing Compressor Station Ambient Noise Level by Controlling Compressor Internal Noise Source

2002 ◽  
Author(s):  
Zheji Liu ◽  
Bill Jahnke ◽  
Mike Marczak ◽  
Paul Kiteck
Keyword(s):  
Noise Level ◽  
High Efficiency ◽  
Noise Source ◽  
Internal Noise ◽  
Sound Intensity ◽  
Control Device ◽  
Third Party ◽  
Intensity Level ◽  
Compressor Station ◽  
Compressor Building

Dresser-Rand single stage pipeline booster compressors have been popular for gas transmission applications due to their high efficiency. As more compressors are installed in natural gas compressor stations close to populated areas, the noise level emitted from the compressor stations becomes a concern. To address the potential community noise concerns, Dresser-Rand recently developed a very effective noise control device — the Duct Resonator array or DR array, to attenuate the internal noise of the compressor, which is typically a major noise source of a compressor station. This technology has been validated by extensive in-house experimental study to be acoustically effective and yet have no measurable adverse effect on aerodynamic performance. This paper discusses the application of DR arrays in two compressors that are in-service at a Williams Gas Pipeline compressor station. Note: the DR arrays are now included in the third unit addition. A successful collaboration among the compressor manufacturer, the compressor user, and a third party acoustics expert was coordinated to take acoustic measurements independently to evaluate the noise reduction provided by the DR arrays. The comprehensive acoustic data acquisition included sound pressure level and sound intensity level measurements around each of the two compressors and several noise level surveys both inside and outside of the compressor building. Noise testing was first performed on each of the two compressors prior to the installation of the DR arrays and was repeated after the compressor hardware modification with DR arrays. A comparison of the noise data recorded before and after the installation of the DR arrays confirmed that the compressor noise level inside the compressor building and the noise level outside of the building were reduced significantly. The DR array has proved to be an efficient and effective device for reducing noise and vibration levels of both existing and new centrifugal compressors and associated piping.

Applications of Sound Intensity Measurements to Gas Turbine Engineering

1992 ◽  
Author(s):  
R. D. Rawlinson
Keyword(s):  
Gas Turbine ◽  
Sound Intensity ◽  
Cost Effective ◽  
Sound Level ◽  
Directional Sensitivity ◽  
Noise Sources ◽  
Offshore Installations ◽  
Practical Reality ◽  
Detailed Assessment ◽  
Level Meter

Recent advances in signal processing techniques have made the measurement of sound intensity a practical reality. The newly developed sound intensity meters can indicate both the magnitude and direction of sound. This is a major advantage over the traditional sound level meter which does not have such directional sensitivity. Sound intensity meters can, therefore, make accurate measurements under adverse conditions, such as onshore or offshore, where sound level meters may be unsuitable. This makes the detailed assessment of the sound power output of a gas turbine package, operating in the field, practicable. Individual components of a gas turbine train can be evaluated so that the dominant noise sources can be identified, thereby providing more cost effective solutions to onshore and offshore installations. This paper describes briefly the concepts of sound intensity, the current state of standards and some aspects of measurement technique. Case histories of the use of sound intensity instrumentation in a variety of situations, relevant to gas turbine engineering, will be described. This will include laboratory and field based investigations.

scholarly journals Cell rearrangement induced by filopodial tension accounts for the late phase of convergent extension in the sea urchin archenteron

2019 ◽  
Vol 30 (16) ◽  
pp. 1911-1919 ◽  
Author(s):  
Jeff Hardin ◽  
Michael Weliky
Keyword(s):  
Sea Urchin ◽  
Late Phase ◽  
Convergent Extension ◽  
Elastic Recoil ◽  
Poisson Effect ◽  
Cell Rearrangement ◽  
Starting Point ◽  
Mechanical Models ◽  
Key Features ◽  
Mesenchyme Cells

George Oster was a pioneer in using mechanical models to interrogate morphogenesis in animal embryos. Convergent extension is a particularly important morphogenetic process to which George Oster gave significant attention. Late elongation of the sea urchin archenteron is a classic example of convergent extension in a monolayered tube, which has been proposed to be driven by extrinsic axial tension due to the activity of secondary mesenchyme cells. Using a vertex-based mechanical model, we show that key features of archenteron elongation can be accounted for by passive cell rearrangement due to applied tension. The model mimics the cell elongation and the Poisson effect (necking) that occur in actual archenterons. We also show that, as predicted by the model, ablation of secondary mesenchyme cells late in archenteron elongation does not result in extensive elastic recoil. Moreover, blocking the addition of cells to the base of the archenteron late in archenteron elongation leads to excessive cell rearrangement consistent with tension-induced rearrangement of a smaller cohort of cells. Our mechanical simulation suggests that responsive rearrangement can account for key features of archenteron elongation and provides a useful starting point for designing future experiments to examine the mechanical properties of the archenteron.

Cavitating Orifice: Flow Regime Transitions and Low Frequency Sound Production

2005 ◽  
Author(s):  
Philippe Testud ◽  
Avraham Hirschberg ◽  
Pierre Moussou ◽  
Yves Aure´gan
Keyword(s):  
Sound Production ◽  
Low Frequency ◽  
Broadband Noise ◽  
Detailed Data ◽  
Hydraulic Conditions ◽  
Circular Orifice ◽  
Vapor Cloud ◽  
Orifice Flow ◽  
Flow Through ◽  
Regime Transitions

Detailed data are provided for the broadband noise in a cavitating pipe flow through a circular orifice in water. Experiments are performed under industrial conditions, i.e., with a pressure drop varying from 3 to 30 bars and a cavitation number in the range 0.10 ≤ σ ≤ 0.77. The speed of sound downstream of the orifice happens to vary spontaneously for a given set of hydraulic conditions. In the intermediate ‘developed cavitation’ regime, whistling associated with periodic vortex shedding is observed. In the ‘super cavitation’ regime, a vapor cloud develops itself and the whistling disappears. The broadband noise in each regime is presented and its dimensionless representation is discussed.

Sign in / Sign up

Export Citation Format

Share Document