Alexander Gavrilov

Implementation of Genetic Programming toward the improvement of acoustic classification performance for different seafloor habitats

Publisher: IEEE

Date: 2005

DOI: 10.1109/OCEANSE.2005.1511788

Pygmy blue and Antarctic blue whale presence, distribution and population parameters in southern Australia based on passive acoustics

Publisher: Elsevier BV

Date: 11-2018

DOI: 10.1016/J.DSR2.2018.09.006

Characteristics of sound propagation in shallow water over an elastic seabed with a thin cap-rock layer

Publisher: Acoustical Society of America (ASA)

Date: 07-2013

DOI: 10.1121/1.4809723

Abstract: Measurements of low-frequency sound propagation over the areas of the Australian continental shelf, where the bottom sediments consist primarily of calcarenite, have revealed that acoustic transmission losses are generally much higher than those observed over other continental shelves and remain relatively low only in a few narrow frequency bands. This paper considers this phenomenon and provides a physical interpretation in terms of normal modes in shallow water over a layered elastic seabed with a shear wave speed comparable to but lower than the water-column sound speed. A theoretical analysis and numerical modeling show that, in such environments, low attenuation of underwater sound is expected only in narrow frequency bands just above the modal critical frequencies which in turn are governed primarily by the water depth and compressional wave speed in the seabed. In addition, the effect of a thin layer of harder cap-rock overlaying less consolidated sediments is considered. Low-frequency transmission loss data collected from an offshore seismic survey in Bass Strait on the southern Australian continental shelf are analyzed and shown to be in broad agreement with the numerical predictions based on the theoretical analysis and modeling using an elastic parabolic equation solution for range-dependent bathymetry.

“Spot” call: A common sound from an unidentified great whale in Australian temperate waters

Publisher: Acoustical Society of America (ASA)

Date: 08-2017

DOI: 10.1121/1.4998608

Abstract: Underwater passive acoustic recordings in the Southern and Indian Oceans off Australia from 2002 to 2016 have regularly captured a tonal signal of about 10 s duration at 22–28 Hz with a symmetrical bell-shaped envelope. The sound is often accompanied by short, higher frequency downsweeps and repeated at irregular intervals varying from 120 to 200 s. It is termed the “spot” call according to its appearance in spectrograms of long-time averaging. Although similar to the first part of an Antarctic blue whale Z-call, evidence suggests the call is produced by another great whale, with the source as yet not identified.

Automatic detection of echolocation clicks based on a Gabor model of their waveform

Publisher: Acoustical Society of America (ASA)

Date: 06-2015

DOI: 10.1121/1.4921609

Abstract: Prior research has shown that echolocation clicks of several species of terrestrial and marine fauna can be modelled as Gabor-like functions. Here, a system is proposed for the automatic detection of a variety of such signals. By means of mathematical formulation, it is shown that the output of the Teager–Kaiser Energy Operator (TKEO) applied to Gabor-like signals can be approximated by a Gaussian function. Based on the inferences, a detection algorithm involving the post-processing of the TKEO outputs is presented. The ratio of the outputs of two moving-average filters, a Gaussian and a rectangular filter, is shown to be an effective detection parameter. Detector performance is assessed using synthetic and real (taken from MobySound database) recordings. The detection method is shown to work readily with a variety of echolocation clicks and in various recording scenarios. The system exhibits low computational complexity and operates several times faster than real-time. Performance comparisons are made to other publicly available detectors including pamguard.

Characterizing marine soundscapes

Publisher: Springer New York

Date: 2016

DOI: 10.1007/978-1-4939-2981-8_31

Abstract: The study of marine soundscapes is becoming widespread and the amount of data collected is increasing rapidly. Data owners (typically academia, industry, government, and defense) are negotiating data sharing and generating potential for data syntheses, comparative studies, analyses of trends, and large-scale and long-term acoustic ecology research. A problem is the lack of standards and commonly agreed protocols for the recording of marine soundscapes, data analysis, and reporting that make a synthesis and comparison of results difficult. We provide a brief overview of the components in a marine soundscape, the hard- and software tools for recording and analyzing marine soundscapes, and common reporting formats.

Characterizing diversity and variation in fish choruses in Darwin Harbour

Publisher: Oxford University Press (OUP)

Date: 07-04-2016

DOI: 10.1093/ICESJMS/FSW037

Abstract: The ersity, intensity, and periodicity of fish sounds can provide a wealth of information on spatial and temporal distribution of soniferous fish and, on occasion, which environmental factors these choruses are driven by. Such information can help predict species presence and understand their movement patterns in the long term. At three sites in Darwin Harbour, Australia, sea-noise loggers on the harbour floor recorded ambient noise over a 2-year period. Many fish calls and nine different chorus types were detected over 50 Hz to 3 kHz. Source species were speculated for four of the choruses and source levels, a precursor to passive acoustic abundance estimates, were identified for two of these. Other calls displayed similarities to choruses detected elsewhere in Australia. All choruses displayed diel cycles with semi-lunar patterns present for three of the chorus types. Time of sunset and temperature were also significantly related to the presence of the most predominant chorus and while not statistically significant, height of high tide and salinity also appeared related. A lack of frequency and temporal partitioning in calling across the choruses in hours of darkness (after sunset) illustrates the complexity of monitoring communities of different vocal species. The study has outlined some of the patterns biological sounds exhibit, which has significant implications for s ling strategies when using soundscapes for temporal and spatial predictive modelling.

Underwater particle motion (acceleration, velocity and displacement) from recreational swimmers, divers, surfers and kayakers

Publisher: Springer Science and Business Media LLC

Date: 08-2017

DOI: 10.1007/S40857-017-0107-6

Underwater noise from offshore oil production vessels

Publisher: Acoustical Society of America (ASA)

Date: 05-2013

DOI: 10.1121/1.4802183

Abstract: Underwater acoustic recordings of six Floating Production Storage and Offloading (FPSO) vessels moored off Western Australia are presented. Monopole source spectra were computed for use in environmental impact assessments of underwater noise. Given that operations on the FPSOs varied over the period of recording, and were sometimes unknown, the authors present a statistical approach to noise level estimation. No significant or consistent aspect dependence was found for the six FPSOs. Noise levels did not scale with FPSO size or power. The 5th, 50th (median), and 95th percentile source levels (broadband, 20 to 2500 Hz) were 188, 181, and 173 dB re 1 μPa @ 1 m, respectively.

High-frequency multibeam echo-sounder measurements of seafloor backscatter in shallow water: Part 2 – Mosaic production, analysis and classification

Publisher: Society for Underwater Technology

Date: 07-2011

DOI: 10.3723/UT.30.013

High-frequency multibeam echo-sounder measurements of seafloor backscatter in shallow water: Part 1 – Data acquisition and processing

Publisher: Society for Underwater Technology

Date: 07-2011

DOI: 10.3723/UT.30.003

The marine soundscape of the Perth Canyon

Publisher: Elsevier BV

Date: 09-2015

DOI: 10.1016/J.POCEAN.2015.05.015

Developing an Underwater Sound Recorder: The Long and Short (Time) of It...

Publisher: Springer Science and Business Media LLC

Date: 08-2017

DOI: 10.1007/S40857-017-0113-8

Fluctuations of Seafloor Backscatter Data From Multibeam Sonar Systems

Publisher: Institute of Electrical and Electronics Engineers (IEEE)

Date: 04-2010

DOI: 10.1109/JOE.2010.2041262

Underwater Sound Sources and Ambient Noise in Fowlers Bay, South Australia, during the Austral Winter

Publisher: Springer Science and Business Media LLC

Date: 27-02-2019

DOI: 10.1007/S40857-019-00150-9

Song variation of the South Eastern Indian Ocean pygmy blue whale population in the Perth Canyon, Western Australia

Publisher: Public Library of Science (PLoS)

Date: 22-01-2019

DOI: 10.1371/JOURNAL.PONE.0208619

A general purpose automatic detector of broadband transient signals in underwater audio

Publisher: IEEE

Date: 05-2018

DOI: 10.1109/OCEANSKOBE.2018.8559259

Comparing the Acoustic Behaviour of the Eastern Indian Ocean Pygmy Blue Whale on Two Australian Feeding Grounds

Publisher: Springer Science and Business Media LLC

Date: 04-04-2021

DOI: 10.1007/S40857-021-00229-2

Vocal characteristics of pygmy blue whales and their change over time

Publisher: Acoustical Society of America (ASA)

Date: 12-2018

DOI: 10.1121/1.3651817

Abstract: Vocal characteristics of pygmy blue whales of the eastern Indian Ocean population were analyzed using data from a hydroacoustic station deployed off Cape Leeuwin in Western Australia as part of the Comprehensive Nuclear-Test-Ban Treaty monitoring network, from two acoustic observatories of the Australian Integrated Marine Observing System, and from in idual sea noise loggers deployed in the Perth Canyon. These data have been collected from 2002 to 2010, inclusively. It is shown that the themes of pygmy blue whale songs consist of ether three or two repeating tonal sounds with harmonics. The most intense sound of the tonal theme was estimated to correspond to a source level of 179 ± 2 dB re 1 μPa at 1 m measured for 120 calls from seven different animals. Short-duration calls of impulsive downswept sound from pygmy blue whales were weaker with the source level estimated to vary between 168 to 176 dB. A gradual decrease in the call frequency with a mean rate estimated to be 0.35 ± 0.3 Hz/year was observed over nine years in the frequency of the third harmonic of tonal sound 2 in the whale song theme, which corresponds to a negative trend of about 0.12 Hz/year in the call fundamental frequency.

Long-term monitoring of soundscapes and deciphering a usable index: Examples of fish choruses from Australia

Publisher: Acoustical Society of America

Date: 2016

DOI: 10.1121/2.0000286

A generic system for the automatic extraction of narrowband signals of biological origin in underwater audio

Publisher: Acoustical Society of America

Date: 2016

DOI: 10.1121/2.0000377

Discovery Projects - Grant ID: DP0559994

Start Date: 2005

End Date: 12-2008

Amount: $90,904.00

Funder: Australian Research Council

Special Research Initiatives - Grant ID: SR0354575

Start Date: 01-2004

End Date: 06-2004

Amount: $30,000.00

Funder: Australian Research Council