|
|
|
|
|
| Parris, Kirsten M.; School of Botany, University of Melbourne, Australia; Australian Research Centre for Urban Ecology, Royal Botanic Gardens Melbourne, Australia; k.parris@unimelb.edu.au; Schneider, Angela; Department of Zoology, University of Melbourne, Australia; angelas@unimelb.edu.au. |
| Roadside habitats are important for a range of taxa including plants, insects, mammals, and birds, particularly in developed countries in which large expanses of native vegetation have been cleared for agriculture or urban development. Although roadside vegetation may provide suitable habitat for many species, resident animals can be exposed to high levels of traffic noise, visual disturbance from passing vehicles, and the risk of collision with cars and trucks. Traffic noise can reduce the distance over which acoustic signals such as song can be detected, an effect known as acoustic interference or masking. Studies from the northern hemisphere show that the singing behavior of birds changes in the presence of traffic noise. We investigated the impact of... |
| Tipo: Peer-Reviewed Reports |
Palavras-chave: Acoustic interference; Ambient noise; Bioacoustics; Conservation biology; Road ecology; Signal design; Traffic noise; Vocal communication.. |
| Ano: 2009 |
|
| |
|
| |
|
|
| Plaisant, M. |
| Empirical models already exist for ambient noise spectral density function of frequency, sea state or wind speed but they give no information on the spatial structure or coherence of the noise field which is essential as soon as array beamforming is involved. We have developed a model which computes the spatial coherence matrix of the noise field due to a continuous distribution of sources located at the sea surface, and also the noise power spectral density after classical beamforming on an equidistant hydrophones linear array. In this model, propagation effects like rays bending due to variations of index of refraction and multiple bottom and surface reflections are taken into account. Principles of the modeling are presented and results demonstrate that... |
| Tipo: Text |
Palavras-chave: Spectral analysis; Models; Wind speed; Sea surface; Surface water waves; Acoustic equipment; Sound waves; Underwater noise; Ambient noise. |
| Ano: 1990 |
URL: http://archimer.ifremer.fr/doc/1990/acte-1143.pdf |
| |
|
|
| Pratt, Martin J.; Wysession, Michael E.; Aleqabi, Ghassan; Wiens, Douglas A.; Nyblade, Andrew A.; Shore, Patrick; Rambolamanana, Gerard; Andriampenomanana, Fenitra; Rakotondraibe, Tsiriandrimanana; Tucker, Robert D.; Barruol, Guilhem; Rindraharisaona, Elisa. |
| The crust and upper mantle of the Madagascar continental fragment remained largely unexplored until a series of recent broadband seismic experiments. An island-wide deployment of broadband seismic instruments has allowed the first study of phase velocity variations, derived from surface waves, across the entire island. Late Cenozoic alkaline intraplate volcanism has occurred in three separate regions of Madagascar (north, central and southwest), with the north and central volcanism active until <1 Ma, but the sources of which remains uncertain. Combined analysis of three complementary surface wave methods (ambient noise, Rayleigh wave cross-correlations, and two-plane-wave) illuminate the upper mantle down to depths of 150 km. The phase-velocity... |
| Tipo: Text |
Palavras-chave: Surface wave; Ambient noise; Tomography; Madagascar; Intraplate volcanism. |
| Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00600/71182/69528.pdf |
| |
|
|
| Leroy, Emmanuelle C; Royer, Jean-yves; Bonnel, Julien; Samaran, Flore. |
| In the past decades, in the context of a changing ocean submitted to an increasing human activity, a progressive decrease in the frequencies (pitch) of blue whale vocalizations has been observed worldwide. Its causes, of natural or anthropogenic nature, are still unclear. Based on 7years of continuous acoustic recordings at widespread sites in the southern Indian Ocean, we show that this observation stands for five populations of large whales. The frequency of selected units of vocalizations of fin, Antarctic, and pygmy blue whales has steadily decreased at a rate of a few tenths of hertz per year since 2002. In addition to this interannual frequency decrease, blue whale vocalizations display seasonal frequency shifts. We show that these intra-annual... |
| Tipo: Text |
Palavras-chave: Large baleen whales; Blue whale calls; Frequency shifts; Frequency decrease; Ambient noise; Bioacoustics. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00516/62730/67109.pdf |
| |
|
|
|
