Sound propagation over the ground with a random spatially-varying surface admittance is investigated. Starting from the Green's theorem, a Dyson equation is derived for the coherent acoustic pressure. Under the Bourret approximation, an explicit expression is deduced and an effective admittance that depends on the correlation function of the admittance fluctuations is exhibited. An asymptotic expression at long range is then obtained. Influence of the randomness on the amplitude of the reflection coefficient and on the wavenumbers of the surface wave component is analyzed. Afterwards, numerical simulations of the linearized Euler equations are carried out and the coherent pressure obtained by an ensemble-averaging over 200 realizations of the admittance is found to be in good agreement with the analytical solution. In the considered examples of grounds, the mean intensity is shown to be similar to the intensity in the non-random case, except near interferences that are smoothened out due to randomness. It is however exemplified that the intensity fluctuations can be large, especially near destructive interferences.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1121/1.5006180 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Effects of sediment properties, distance from source, and frequency weighting on sound pressure and sound pressure kurtosis for marine airgun signaturesa).
J Acoust Soc Am
December 2024
Faculty of Civil Engineering and Geosciences, Delft University of Technology, Stevinweg 1, 2628 CN, Delft, The Netherlands.
Investigation of sound pressure waveforms helps the selection of appropriate metrics to evaluate their effects on marine life in relation to noise thresholds. As marine animals move farther away from a sound source, the temporal characteristics of sound pressure may be influenced by interactions with the sediment and the sea surface. Sound pressure kurtosis and root-mean-square (rms) sound pressure are quantitative characteristics that depend on the shape of a sound pulse, with kurtosis related to the qualitative characteristic "impulsiveness.
View Article and Find Full Text PDFNoise pollution mitigation and control in urban areas near international borders through 2D noise mapping.
Sci Rep
December 2024
Business Administration Group, University of Aleppo, Aleppo, Syria.
Noise pollution is defined as any disturbing or unwanted sound that disrupts or harms human health or wildlife. Noise pollution can have profound effects on both human health and the environment. For humans, exposure to excessive noise levels has been linked to a range of health issues, including hearing damage, stress, and sleep disturbances.
View Article and Find Full Text PDFEstimating received level in behavioral response studies through the use of ancillary data.
J Acoust Soc Am
December 2024
Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, USA.
Marine mammals are known to respond to various human noises, including and in certain cases, strongly, to military active sonar. Responses include small and short-term changes in diving behavior, horizontal avoidance of an ensonified area, and mass strandings. Considerable research has been conducted using short-term biologging tags to understand these responses.
View Article and Find Full Text PDFA comparative study of experimental and simulated ultrasound beam propagation through cranial bones.
Phys Med Biol
December 2024
Department of Medical Physics and Bioengineering, University College London, Gower Street, London, WC1E 6BT, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND.
Transcranial ultrasound is used in a variety of treatments, including neuromodulation, opening the blood-brain barrier (BBB), and high intensity focused ultrasound (HIFU) therapies. To ensure safety and efficacy of these treatments, numerical simulations of the ultrasound field within the brain are used for treatment planning and evaluation. This study investigates the accuracy of numerical modelling of the propagation of focused ultrasound through cranial bones.
View Article and Find Full Text PDFNonlinear interaction of an acoustical wave with a counter-propagating weak shock.
J Acoust Soc Am
December 2024
PIMM Laboratory, UMR 8006, Arts et Metiers Institute of Technology (ENSAM), CNRS, Cnam, 151 boulevard de l'Hôpital, 75013, Paris, France.
During its propagation, a shock wave may come across and interact with different perturbations, including acoustical waves. While this issue has been the subject of many studies, the particular acoustic-acoustic interaction between a weak shock and a sound wave has been very scarcely investigated. Here, a theory describing the encounter of those two waves is developed, up to second- and third-order.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!