scholarly journals Stream ambient noise, spectrum and propagation of sounds in the goby Padogobius martensii: Sound pressure and particle velocity

2007 ◽  
Vol 122 (5) ◽  
pp. 2881 ◽  
Author(s):  
Marco Lugli ◽  
Michael L. Fine
Keyword(s):  
Particle Velocity ◽  
Ambient Noise ◽  
Sound Pressure ◽  
Noise Spectrum

Vector Ocean Ambient Noise Spectrum Simulation Based on Parabolic Equation Model in Shallow Water

2017 ◽  
Vol 25 (02) ◽  
pp. 1750034
Author(s):  
Liufang Fu ◽  
Peng Li ◽  
Xinhua Zhang ◽  
Shuqing Ma ◽  
Chengzhi Gao
Keyword(s):  
Parabolic Equation ◽  
South China Sea ◽  
Particle Velocity ◽  
South China ◽  
Ambient Noise ◽  
Sound Pressure ◽  
Noise Spectrum ◽  
China Sea ◽  
Simulation Results ◽  
Horizontal Particle

Ocean ambient noise spectrum is one of the most important characteristics of ambient noise. An ocean vector ambient noise field model was built up based on parabolic equation in this paper. Then the spectra of sound pressure, horizontal particle velocity and vertical particle velocity were calculated applying the model considering noise sources well distributed on the surface with typical summer sound speed profile in South China Sea. The simulation results showed that spectra of sound pressure, horizontal particle velocity and vertical particle velocity were obviously not varied with depth. Then, the simulated results were compared with the experiment results at the receiving depth of a trail in South China Sea in July 2012. Compared with the experimental results, the simulation results are consistent well with the experimental one of sound pressure and horizontal particle velocity in the trend. But the simulation values at low frequency band below 500[Formula: see text]Hz, are not consistent with the experimental one very well, in the band the simulation results are lower than the experimental by about 3–5[Formula: see text]dB. But the simulation result of vertical particle velocity was not consistent with the experimental one, illustrating that the precision of the model might not be enough in the vertical direction.

Offshore Marine Ambient Noise Measurement Study Based on Laser Interferometer Hydrophone

2014 ◽  
Vol 945-949 ◽  
pp. 746-749
Author(s):  
Zhi Li Hua ◽  
Lei Li ◽  
Zhong Hai Zhou
Keyword(s):  
Background Noise ◽  
Ambient Noise ◽  
Sound Pressure ◽  
Laser Interferometer ◽  
Noise Spectrum ◽  
Materials Selection ◽  
Wind Noise ◽  
Radiation Noise ◽  
Vibrating Membrane ◽  
Laser Interferometric

Sound pressure is an important parameter of marine background noise monitoring. A laser interferometric hydrophone is designed based on Michelson interferometry. By tracking compensation method, immunity from interference of the hydrophone is improved. Error analysis shows that the vibrating membrane is the main source of the sound pressure error, which can be eliminated to a certain extent by a vibrating membrane materials selection. Offshore data show that hydrophone pressure measurement of high precision, and with a good frequency response. By comparison with the theoretical model to some extent also verified the accuracy of data. In coastal waters, wind noise and ship radiate noise is the main noise source of marine ambient noise. Here, marine ambient noise spectrum of three wind speed were calculated, and with Kundsen curves were compared. Results show that measured data and Kundsen curve fitting is better. In addition, the measurement of vessel radiation noise is mainly concentrated in frequency range of 350~500Hz.

scholarly journals Measurement of Underwater Acoustic Energy Radiated by Single Raindrops

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2687
Author(s):  
Shu Liu ◽  
Qi Li ◽  
Dajing Shang ◽  
Rui Tang ◽  
Qingming Zhang
Keyword(s):  
Ambient Noise ◽  
Sound Pressure ◽  
Tap Water ◽  
Acoustic Energy ◽  
Underwater Sound ◽  
Underwater Noise ◽  
Energy Characteristics ◽  
Sound Energy ◽  
Dipole Radiation ◽  
Series Of Experiments

Underwater noise produced by rainfall is an important component of underwater ambient noise. For example, the existence of rainfall noise causes strong disturbances to sonar performance. The underwater noise produced by a single raindrop is the basis of rainfall noise. Therefore, it is necessary to study the associated underwater noise when drops strike the water surface. Previous research focused primarily on the sound pressure and frequency spectrum of underwater noise from single raindrops, but the study on its sound energy is insufficient. The purpose of this paper is to propose a method for predicting the acoustic energy generated by raindrops of any diameter. Here, a formula was derived to calculate the underwater sound energy radiated by single raindrops based on a dipole radiation pattern. A series of experiments were conducted to measure the underwater sound energy in a 15 m × 9 m × 6 m reverberation tank filled with tap water. The analysis of the acoustic energy characteristics and conversion efficiency from kinetic to acoustic energy helped develop the model to predict the average underwater sound energy radiated by single raindrops. Using this model, the total underwater sound energy of all raindrops during a rainfall event can be predicted based on the drop size distribution.

Spatial variation of ocean ambient noise spectrum in offshore China

2016 ◽  
Vol 140 (4) ◽  
pp. 3351-3351
Author(s):  
Guoli Song ◽  
Xinyi Guo ◽  
Li Ma ◽  
Qianchu Zhang
Keyword(s):  
Spatial Variation ◽  
Ambient Noise ◽  
Noise Spectrum

Development of Particle Velocity Transfer Path Analysis

2012 ◽  
Author(s):  
Akira Inoue ◽  
Yosuke Tanabe
Keyword(s):  
Path Analysis ◽  
Particle Velocity ◽  
Velocity Vector ◽  
Degrees Of Freedom ◽  
Sound Pressure ◽  
Simple Method ◽  
Transfer Path ◽  
Rank Ordering ◽  
Transfer Path Analysis ◽  
Velocity Transmission

The transfer path analysis (TPA) in terms of sound pressure has been implemented for decades in many application areas, such as car, train and construction machine. In this article, we propose a transfer path analysis where particle velocity is employed as the measure of TPA. Sound pressure is a scalar quantity, while particle velocity, which is the other fundamental quantity of sound, is a vector quantity. The phase differences among particle velocity vector components have to be generally considered. For TPA, not only the six degrees-of-freedom of each path motion, but also the three degrees-of-freedom of the particle velocity at the receiver location have to be considered together for an effective path rank ordering. We first propose the formulation of the particle velocity transfer path analysis where the same formulation of the standard sound pressure transfer path analysis is assumed to hold true for each direction of particle velocity. In order to verify the proposed particle velocity transfer path analysis, we carry out an experiment using a simple test box structure. As a result we have found that the error in the particle velocity vector synthesis is acceptably small, and is as small as the error in the standard sound pressure synthesis, which indicates that the same synthesis method can be employed. We then perform rank ordering of the particle velocity transmission paths. Here, a simple method of path rank ordering is applied. Lastly, we briefly discuss sound energy as a measure of TPA.

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