scholarly journals Signaler–receiver–eavesdropper: Risks and rewards of variation in the dominant frequency of male cricket calls

2020 ◽  
Vol 10 (21) ◽  
pp. 12364-12371
Author(s):  
Olivia L. Dobbs ◽  
Janelle B. Talavera ◽  
Sarina M. Rossi ◽  
Stephanie Menjivar ◽  
David A. Gray
Keyword(s):  
Dominant Frequency ◽  
Male Cricket

Correlations between call characteristics and morphology in male cricket frogs (Acris crepitans).

1996 ◽  
Vol 199 (9) ◽  
pp. 1907-1919
Author(s):  
B E McClelland ◽  
W Wilczynski ◽  
M J Ryan
Keyword(s):  
Body Size ◽  
Size Effects ◽  
Spectral Characteristics ◽  
Morphological Characteristics ◽  
Dominant Frequency ◽  
Advertisement Call ◽  
Acris Crepitans ◽  
Species Specific ◽  
Male Cricket ◽  
Cricket Frogs

We investigated the relationships among spectral and temporal advertisement-call characteristics and the sizes of the laryngeal and ear components thought to underlie the generation and reception of species-specific vocalizations in male cricket frogs (Acris crepitans). We tested the predictions that the volumes of the structural elements necessary for acoustic communication would be correlated with various parameters of the vocalizations. The anatomy of laryngeal and ear structures was reconstructed from serial sections of the heads of male cricket frogs of two subspecies collected from several sites across the range of this species in Texas, USA. The relationships among the anatomy and call parameters were assessed using several univariate and multivariate analyses. Highly significant univariate correlations among the laryngeal components suggest that the temporal and spectral characteristics of the calls are not independently produced. Dominant frequency correlates strongly with most of the other call and morphological characteristics. Removing body size effects, however, removes the relationship between dominant frequency and the volume of the whole larynx and ear. This is also the case for call pulse rate, indicating that for this species both spectral and temporal call parameters are biomechanically related to laryngeal size which is, in turn, largely mediated by body size. General body size effects might also explain the existence of significant relationships between ear size and temporal characteristics of the call that probably do not have a functional basis.

Modeling Vibration-Induced Tire-Pavement Interaction Noise in the Mid-frequency Range

2020 ◽  
Author(s):  
Sterling McBride ◽  
Ricardo Burdisso ◽  
Corina Sandu
Keyword(s):  
Sound Intensity ◽  
Element Model ◽  
Dominant Frequency ◽  
Contact Forces ◽  
Surface Velocity ◽  
New Wave ◽  
Normal Surface ◽  
Radiated Noise ◽  
Physical Effects ◽  
Effects Of Rotation

ABSTRACT Tire-pavement interaction noise (TPIN) is one of the main sources of exterior noise produced by vehicles traveling at greater than 50 kph. The dominant frequency content is typically within 500–1500 Hz. Structural tire vibrations are among the principal TPIN mechanisms. In this work, the structure of the tire is modeled and a new wave propagation solution to find its response is proposed. Multiple physical effects are accounted for in the formulation. In an effort to analyze the effects of curvature, a flat plate and a cylindrical shell model are presented. Orthotropic and nonuniform structural properties along the tire's transversal direction are included to account for differences between its sidewalls and belt. Finally, the effects of rotation and inflation pressure are also included in the formulation. Modeled frequency response functions are analyzed and validated. In addition, a new frequency-domain formulation is presented for the computation of input tread pattern contact forces. Finally, the rolling tire's normal surface velocity response is coupled with a boundary element model to demonstrate the radiated noise at the leading and trailing edge locations. These results are then compared with experimental data measured with an on-board sound intensity system.

Active control of compressor noise in the machinery room of refrigerators

2019 ◽  
Vol 67 (5) ◽  
pp. 350-362
Author(s):  
J. M. Ku ◽  
W. B. Jeong ◽  
C. Hong
Keyword(s):  
Control System ◽  
Active Control ◽  
Weighting Function ◽  
Reference Signal ◽  
Active Noise Control ◽  
Dominant Frequency ◽  
Time Signal ◽  
Frequency Noise ◽  
Sound Power ◽  
Fxlms Algorithm

The low-frequency noise generated by the vibration of the compressor in the machinery room of refrigerators is considered as annoying sound. Active noise control is used to reduce this noise without any change in the design of the compressor in the machinery room. In configuring the control system, various signals are measured and analyzed to select the reference signal that best represents the compressor noise. As the space inside the machinery room is small, the size of a speaker is limited, and the magnitude of the controller transfer function is designed to be small at low frequencies, the controller uses FIR filter structure converged by the FxLMS algorithm using the pre-measured time signal. To manage the convergence speed for each frequency, the frequency-weighting function is applied to FxLMS algorithm. A series of measurements are performed to design the controller and to evaluate the control performance. After the control, the sound power transmitted by the refrigerator is reduced by 9 dB at the first dominant frequency (408 Hz in this case) and 3 dB at the second dominant frequency (459 Hz here), and the overall sound power decreases by 2.6 dB. Through this study, an active control system for the noise generated by refrigerator compressors is established.

A proposed wavy shield for suppression of supersonic jet noise utilizing reflections

2021 ◽  
Vol 20 (1-2) ◽  
pp. 4-34
Author(s):  
Reda R Mankbadi ◽  
Saman Salehian
Keyword(s):  
Large Scale ◽  
Flat Surface ◽  
Near Field ◽  
Supersonic Jet ◽  
Jet Noise ◽  
Dominant Frequency ◽  
Wavy Surface ◽  
Initial Region ◽  
Reflected Waves ◽  
Free Jet

In this work we propose replacing the conventional flat-surface airframe that shields the engine by a wavy surface. The basic principle is to design a wavy pattern to reflect the incoming near-field flow and acoustic perturbations into waves of a particular dominant frequency. The reflected waves will then excite the corresponding frequency of the large-scale structure in the initial region of the jet’s shear layer. By designing the frequency of the reflected waves to be the harmonic of the fundamental frequency that corresponds to the radiated peak noise, the two frequency-modes interact nonlinearly. With the appropriate phase difference, the harmonic dampens the fundamental as it extracts energy from it to amplify. The outcome is a reduction in the peak noise. To evaluate this concept, we conducted Detached Eddy Simulations for a rectangular supersonic jet with and without the wavy shield and verified our numerical results with experimental data for a free jet, as well as, for a jet with an adjacent flat surface. Results show that the proposed wavy surface reduces the jet noise as compared to that of the corresponding flat surface by as much as 4 dB.

The dominant frequency analysis of interfacial wave in wet-gas pipeline transportation based on NIR absorption

2021 ◽  
pp. 1-10
Author(s):  
Zhiyue Zhao ◽  
Ning Zhao ◽  
Lide Fang ◽  
Xiaoting Li
Keyword(s):  
Liquid Film ◽  
Predictive Accuracy ◽  
Film Surface ◽  
Dominant Frequency ◽  
Wave Frequency ◽  
Interfacial Wave ◽  
Long Distance ◽  
Wet Gas ◽  
The Mean ◽  
Predictive Correlation

During the long-distance transportation of wet-gas, the dominant frequency is of great significance for the study of pipeline fatigue and damage, and the safety production. Therefore, the theoretical and experimental researches for dominant frequency are carried out increasingly. However, most of the current prediction correlation of dominant frequency are mainly applicable to atmospheric pressure conditions (0.1 MPa), and the prediction accuracy is not accurate enough. The paper obtains the time series signal of liquid film thickness by near-infrared (NIR) sensor, and then calculates the wave frequency by the power spectrum density (PSD). The performance of typical predictive correlation is evaluated and analyzed by utilizing the experimental data at different flow and pressure conditions (0.1–0.8) MPa. The structure of Strouhal number and Lockhart-Martinelli (L-M) parameter are optimized reasonably, the mean velocity of the liquid film surface, the density increment of gas core, the gas core mass flow and average liquid film velocity are considered in the L-M parameter, a modified interfacial wave frequency correlation is proposed. The results indicate that the mean absolute error of the predictive correlation is 9.06% (current data) and 25.64% (literature data). The new correlation has a better predictive accuracy.

Experimental modeling of adjacent parallel shield tunnels subjected to train-induced vibration loads

2021 ◽  
pp. 095440972098626
Author(s):  
Junchen Zhang ◽  
Qixiang Yan ◽  
Kai Yang ◽  
Minghui Sun
Keyword(s):  
Experimental Studies ◽  
Bimodal Distribution ◽  
Dominant Frequency ◽  
Experimental Modeling ◽  
Load Curve ◽  
Hilbert Huang Transform ◽  
Frequency Peak ◽  
Train Speed ◽  
Vibration Loads ◽  
Train Induced Vibration

Previous studies have performed numerical simulations of adjacent parallel shield tunnels under train-induced vibration loads. However, few experimental studies have been performed for the interaction mechanisms. In this study, experimental modeling is conduced to explore the interaction of adjacent parallel shield tunnels subjected to different train-induced vibration loads. A new Hilbert-Huang transform (HHT) is applied to obtain the instantaneous responses of tunnels. The results show that the acceleration of the tunnel follows the trend of the train load curve. The peak accelerations of the tunnels experience a unimodal distribution along the train speed, while the dominant frequencies of the tunnels follow a bimodal distribution. The interaction between the adjacent parallel tunnels is significant. The transform of the vibration loads to the adjacent tunnel is through the soil below the tunnel. The farther away from the train load is, the greater the train speed corresponding to the dominant frequency peak.

Wavelet network-based classification of transients using dominant frequency signature

2008 ◽  
Vol 78 (1) ◽  
pp. 21-29 ◽  
Author(s):  
Saibal Chatterjee ◽  
Sivaji Chakravorti ◽  
Chinmoy Kanti Roy ◽  
Debangshu Dey
Keyword(s):  
Dominant Frequency ◽  
Wavelet Network
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