A perspective on 30 years of progress in ambient noise: Source mechanisms and the characteristics of the sound field

2012 ◽  
Author(s):  
Douglas H. Cato
Keyword(s):  
Ambient Noise ◽  
Noise Source ◽  
Sound Field ◽  
Source Mechanisms

A Method for Noise Source Levels Inversion with Underwater Ambient Noise Generated by Typhoon in Deep Ocean

2018 ◽  
Vol 26 (02) ◽  
pp. 1850007 ◽  
Author(s):  
Qiulong Yang ◽  
Kunde Yang ◽  
Shunli Duan
Keyword(s):  
Ambient Noise ◽  
Noise Source ◽  
Surface Wind ◽  
Deep Ocean ◽  
Noise Sources ◽  
Noise Field ◽  
Sea Surface Wind ◽  
Source Level ◽  
The Western Pacific ◽  
Good Agreement

Sea-surface wind agitation can be considered the dominant noise sources whose intensity relies on local wind speed during typhoon period. Noise source levels in previous researches may be unappreciated for all oceanic regions and should be corrected for modeling typhoon-generated ambient noise fields in deep ocean. This work describes the inversion of wind-driven noise source level based on a noise field model and experimental measurements, and the verification of the inverted noise source levels with experimental results during typhoon period. A method based on ray approach is presented for modeling underwater ambient noise fields generated by typhoons in deep ocean. Besides, acoustic field reciprocity is utilized to decrease the calculation amount in modeling ambient noise field. What is more, the depth dependence and the vertical directionality of noise field based on the modeling method and the Holland typhoon model are evaluated and analyzed in deep ocean. Furthermore, typhoons named “Soulik” in 2013 and “Nida” in 2016 passed by the receivers deployed in the western Pacific (WP) and the South China Sea (SCS). Variations in sound speed profile, bathymetry, and the related oceanic meteorological parameters are analyzed and taken into consideration for modeling noise field. Boundary constraint simulated annealing (SA) method is utilized to invert the three parameters of noise source levels and to minimize the objective function value. The prediction results with the inverted noise source levels exhibit good agreement with the measured experiment data and are compared with predicted results with other noise sources levels derived in previous researches.

Sound Source Identification and Acoustic Contribution Analysis Using Nearfield Acoustic Holography

2014 ◽  
Vol 945-949 ◽  
pp. 717-724 ◽  
Author(s):  
Jiang Hua Deng ◽  
Jun Hong Dong ◽  
Guang De Meng
Keyword(s):  
Source Identification ◽  
Noise Source ◽  
Near Field ◽  
Superposition Principle ◽  
Sound Field ◽  
Mirror Image ◽  
Sound Sources ◽  
Incoming Wave ◽  
Reflected Waves ◽  
Acoustic Contribution

The main goal of the present paper is to provide a method of source identification. Firstly, statistically optimal near-field acoustical holography (SONAH) techniques are applied to locate sound sources with the reflected sound field. In the presence of reflection plane parallel and perpendicular to the source plane, the incoming wave and reflected waves are separated based on the acoustic superposition principle and acoustic mirror image principle to satisfy the condition of the sound sources reconstruction using SONAH. Secondly, contribution of noise source to the special field point is analyzed and noise source ranking of interior panel groups are evaluated based the proposed three step acoustic contribution method. Finally, this method is verified experimentally.

Noise Source Mechanisms

1992 ◽  
pp. 313-354 ◽  
Author(s):  
D. G. Crighton ◽  
A. P. Dowling ◽  
J. E. Ffowcs Williams ◽  
M. Heckl ◽  
F. G. Leppington
Keyword(s):  
Noise Source ◽  
Source Mechanisms

An analysis of low‐frequency wind‐generated ambient noise source levels in the ocean

1988 ◽  
Vol 83 (S1) ◽  
pp. S87-S87
Author(s):  
W. M. Carey ◽  
D. J. Kewley ◽  
D. G. Browning ◽  
W. A. Von Winkle
Keyword(s):  
Ambient Noise ◽  
Noise Source ◽  
Low Frequency

Wind‐generated, low‐frequency, ambient‐noise source levels revisited

1999 ◽  
Vol 106 (4) ◽  
pp. 2297-2297
Author(s):  
William M. Carey ◽  
David G. Browning
Keyword(s):  
Ambient Noise ◽  
Noise Source ◽  
Low Frequency

Study on Acoustic Model of Transformer

2014 ◽  
Vol 1008-1009 ◽  
pp. 571-575
Author(s):  
Jing Zhu Hu ◽  
Di Chen Liu ◽  
Qing Fen Liao ◽  
Su Wei ◽  
Lei Yu
Keyword(s):  
Noise Level ◽  
Noise Control ◽  
Noise Source ◽  
Sound Field ◽  
Point Sources ◽  
Equivalent Model ◽  
Noise Prediction ◽  
Acoustic Model ◽  
Plane Source ◽  
Equivalent Source

The model of transformer as a noise source is very critical for substation noise prediction. The transformer is equivalent to several point sources on the basis of regarding the transformer as a combination of several planar sources. This equivalent model is based on equivalent source method and it is convenient and easy. The model of 9 equivalent point sources is simulated to verify that the rebuilt sound field is roughly the same as the actual sound field generated by the plane source. Moreover, the accuracy of the model with different settings was discussed. The acoustic model is accurate and feasible to calculate the noise level radiated by transformer and it is meaningful for substation noise control.

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