Propagating impulse sounds are sensitive to the varying near-surface atmosphere. This study reports on an experimental assessment of this sensitivity under well-controlled outdoor conditions. The experiment, conducted over a flat terrain, features 14 synchronous acoustic sensors at ranges up to 450 m from reproducible, transient sources. It scanned over the upwind, crosswind, and downwind propagations, and also documents the temporal and spatial coherences of the acoustic field. Concurrent atmospheric measurements documented the near-surface, essentially wind-driven atmosphere, and included turbulence monitoring. The analysis reveals how the environmental propagation processes combine to form the large variety of recorded signatures. The deterministic versus stochastic variations of the signatures are distinguished, and both are shown to affect the time of arrival (wander) and the shape (spread) of the pulses. The study also discusses the potential impacts of these variations on acoustic sensing of transient signals like gun shots and explosions.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1121/1.5047750 | DOI Listing |
J Acoust Soc Am
January 2025
Acoustic Technology, Department of Electrical & Photonics Engineering, Technical University of Denmark, Kongens Lyngby, Denmark.
Characterising acoustic fields in rooms is challenging due to the complexity of data acquisition. Sound field reconstruction methods aim at predicting the acoustic quantities at positions where no data are available, incorporating generalisable physical priors of the sound in a room. This study introduces a model that exploits the general time structure of the room impulse response, where a wave-based expansion addresses the direct sound and early reflections, localising their apparent origin, and kernel methods are applied to the late part.
View Article and Find Full Text PDFClin Otolaryngol
December 2024
Consultant ENT Surgeon, Department of Otolaryngology Head and Neck Surgery, Manchester Royal Infirmary; Honorary Senior Lecturer, University of Manchester, Manchester, UK.
Objectives: A recent paper by Moore, Lowe and Cox has proposed guidelines for diagnosing noise-induced hearing loss (NIHL). It is referred to here as the MLC guidelines. Our aim was to assess the specificity of those guidelines (i.
View Article and Find Full Text PDFJ Acoust Soc Am
December 2024
Department of Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA.
This article presents a spatial environmental inversion scheme using broadband impulse signals with deep learning (DL) to model a single spatially-varying sediment layer over a fixed basement. The method is applied to data from the Seabed Characterization Experiment 2022 (SBCEX22) in the New England Mud-Patch (NEMP). Signal Underwater Sound (SUS) explosive charges generated impulsive signals recorded by a distributed array of bottom-moored hydrophones.
View Article and Find Full Text PDFJ 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 PDFJ Acoust Soc Am
December 2024
Naval Physical and Oceanographic Laboratory, Defence Research and Development Organisation, Thrikkakara P. O., Kochi, Kerala 682021, India.
An acoustic propagation experiment was conducted in the western continental shelf of India (off Kollam, Kerala) in water depth of ∼71 m with seafloor consisting of hard sandy sediments. The multipath arrival times are obtained from peaks in acoustic impulse response measurements made on a single hydrophone for two source-receiver ranges of 245 m and 320 m. The arrival times are used for inverting the water column sound speed profile (SSP) utilizing the empirical orthogonal functions (EOFs), which can completely describe large datasets.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!