scholarly journals A Case Study of Whistle Detection and Localization for Humpback Dolphins in Taiwan

2021 ◽  
Vol 9 (7) ◽  
pp. 725
Author(s):  
Ching-Tang Hung ◽  
Wei-Yen Chu ◽  
Wei-Lun Li ◽  
Yen-Hsiang Huang ◽  
Wei-Chun Hu ◽  
...  
Keyword(s):  
Sound Source ◽  
Marine Mammal ◽  
Offshore Wind ◽  
Real Field ◽  
Ecological Disturbance ◽  
Localization Accuracy ◽  
Passive Acoustic ◽  
Detection And Localization ◽  
Moving Path ◽  
Detection Processing

In recent years, Taiwan’s government has focused on policies regarding offshore wind farming near the Indo-Pacific humpback dolphin habitat, where marine mammal observation is a critical consideration. The present research developed an algorithm called National Taiwan University Passive Acoustic Monitoring (NTU_PAM) to assist marine mammal observers (MMOs). The algorithm performs whistle detection processing and whistle localization. Whistle detection processing is based on image processing and whistle feature extraction; whistle localization is based on the time difference of arrival (TDOA) method. To test the whistle detection performance, we used the same data to compare NTU_PAM and the widely used software PAMGuard. To test whistle localization, we designed a real field experiment where a sound source projected simulated whistles, which were then recorded by several hydrophone stations. The data were analyzed to locate the moving path of the source. The results show that localization accuracy was higher when the sound source position was in the detection region composed of hydrophone stations. This paper provides a method for MMOs to conveniently observe the migration path and population dynamics of cetaceans without ecological disturbance.

Role of pinnae and head movements in localizing pure tones 1The authors would like to thank Mr. Remi Humbert for implementing the experiment in Turbo Pascal and for his further assistance.

1999 ◽  
Vol 58 (3) ◽  
pp. 170-179 ◽  
Author(s):  
Barbara S. Muller ◽  
Pierre Bovet
Keyword(s):  
Sound Source ◽  
Head Movement ◽  
Movement Analysis ◽  
Head Movements ◽  
Sound Sources ◽  
Localization Accuracy ◽  
Sound Effects ◽  
Posterior Quadrant ◽  
Localization Performance ◽  
Pure Tones

Twelve blindfolded subjects localized two different pure tones, randomly played by eight sound sources in the horizontal plane. Either subjects could get information supplied by their pinnae (external ear) and their head movements or not. We found that pinnae, as well as head movements, had a marked influence on auditory localization performance with this type of sound. Effects of pinnae and head movements seemed to be additive; the absence of one or the other factor provoked the same loss of localization accuracy and even much the same error pattern. Head movement analysis showed that subjects turn their face towards the emitting sound source, except for sources exactly in the front or exactly in the rear, which are identified by turning the head to both sides. The head movement amplitude increased smoothly as the sound source moved from the anterior to the posterior quadrant.

Subjective evaluation of the combining effect between the virtual bass and head related transfer functions

2021 ◽  
Vol 263 (5) ◽  
pp. 1488-1496
Author(s):  
Yunqi Chen ◽  
Chuang Shi ◽  
Hao Mu
Keyword(s):  
Fundamental Frequency ◽  
Sound Source ◽  
Transfer Functions ◽  
Subjective Evaluation ◽  
Low Frequency ◽  
Localization Accuracy ◽  
Frequency Sound ◽  
Listening Tests ◽  
Listening Experience ◽  
Missing Fundamental

Earphones are commonly equipped with miniature loudspeaker units, which cannot transmit enough power of low-frequency sound. Meanwhile, there is often only one loudspeaker unit employed on each side of the earphone, whereby the multi-channel spatial audio processing cannot be applied. Therefore, the combined usage of the virtual bass (VB) and head-related transfer functions (HRTFs) is necessary for an immersive listening experience with earphones. However, the combining effect of the VB and HRTFs has not been comprehensively reported. The VB is developed based on the missing fundamental effect, providing that the presence of harmonics can be perceived as their fundamental frequency, even if the fundamental frequency is not presented. HRTFs describe the transmission process of a sound propagating from the sound source to human ears. Monaural audio processed by a pair of HRTFs can be perceived by the listener as a sound source located in the direction associated with the HRTFs. This paper carries out subjective listening tests and their results reveal that the harmonics required by the VB should be generated in the same direction as the high-frequency sound. The bass quality is rarely distorted by the presence of HRTFs, but the localization accuracy is occasionally degraded by the VB.

Glider-Based Passive Acoustic Monitoring in the Arctic

2014 ◽  
Vol 48 (5) ◽  
pp. 40-51 ◽  
Author(s):  
Mark F. Baumgartner ◽  
Kathleen M. Stafford ◽  
Peter Winsor ◽  
Hank Statscewich ◽  
David M. Fratantoni
Keyword(s):  
Real Time ◽  
Marine Mammal ◽  
Low Frequency ◽  
Acoustic Monitoring ◽  
Bowhead Whale ◽  
The Arctic ◽  
Mammal Species ◽  
Frequency Detection ◽  
Passive Acoustic ◽  
The Impact

AbstractPersistently poor weather in the Arctic makes traditional marine mammal research from aircraft and ships difficult, yet collecting information on marine mammal distribution and habitat utilization is vital for understanding the impact of climate change on Arctic ecosystems. Moreover, as industrial use of the Arctic increases with the expansion of the open-water summer season, there is an urgent need to monitor the effects of noise from oil and gas exploration and commercial shipping on marine mammals. During September 2013, we deployed a single Slocum glider equipped with a digital acoustic monitoring (DMON) instrument to record and process in situ low-frequency (<5 kHz) audio to characterize marine mammal occurrence and habitat as well as ambient noise in the Chukchi Sea off the northwest coast of Alaska, USA. The DMON was programmed with the low-frequency detection and classification system (LFDCS) to autonomously detect and classify sounds of a variety of Arctic and sub-Arctic marine mammal species. The DMON/LFDCS reported regularly in near real time via Iridium satellite detailed detection data, summary classification information, and spectra of background noise. The spatial distributions of bowhead whale, bearded seal, and walrus call rates were correlated with surface salinity measured by the glider. Bowhead whale and walrus call rates were strongly associated with a warm and salty water mass of Bering Sea origin. With a passive acoustic capability that allows both archival recording and near real-time reporting, we envision ocean gliders will become a standard tool for marine mammal and ocean noise research and monitoring in the Arctic.

Noise-Robust MUSIC-Based Sound Source Localization Using Steering Vector Transformation for Small Humanoids

2017 ◽  
Vol 29 (1) ◽  
pp. 26-36 ◽  
Author(s):  
Ryu Takeda ◽  
◽  
Kazunori Komatani
Keyword(s):  
Source Localization ◽  
Sound Source ◽  
Computational Cost ◽  
Internal Noise ◽  
Humanoid Robots ◽  
Eigenvalue Decomposition ◽  
Sound Source Localization ◽  
Noise Robustness ◽  
Localization Accuracy ◽  
Steering Vector

[abstFig src='/00290001/03.jpg' width='300' text='Sound source localization and problem' ] We focus on the problem of localizing soft/weak voices recorded by small humanoid robots, such as NAO. Sound source localization (SSL) for such robots requires fast processing and noise robustness owing to the restricted resources and the internal noise close to the microphones. Multiple signal classification using generalized eigenvalue decomposition (GEVD-MUSIC) is a promising method for SSL. It achieves noise robustness by whitening robot internal noise using prior noise information. However, whitening increases the computational cost and creates a direction-dependent bias in the localization score, which degrades the localization accuracy. We have thus developed a new implementation of GEVD-MUSIC based on steering vector transformation (TSV-MUSIC). The application of a transformation equivalent to whitening to steering vectors in advance reduces the real-time computational cost of TSV-MUSIC. Moreover, normalization of the transformed vectors cancels the direction-dependent bias and improves the localization accuracy. Experiments using simulated data showed that TSV-MUSIC had the highest accuracy of the methods tested. An experiment using real recoded data showed that TSV-MUSIC outperformed GEVD-MUSIC and other MUSIC methods in terms of localization by about 4 points under low signal-to-noise-ratio conditions.

A Passive Acoustic Positioning Algorithm Based on Virtual Long Baseline Matrix Window

2018 ◽  
Vol 72 (1) ◽  
pp. 193-206 ◽  
Author(s):  
Tao Zhang ◽  
Ziqiang Wang ◽  
Yao Li ◽  
Jinwu Tong
Keyword(s):  
Sound Source ◽  
Cross Correlation ◽  
Autonomous Underwater Vehicles ◽  
Underwater Sound ◽  
Positioning Systems ◽  
Long Baseline ◽  
Positioning Method ◽  
Passive Acoustic ◽  
Positioning Algorithm ◽  
Acoustic Positioning

A new acoustic positioning method for Autonomous Underwater Vehicles (AUV) that uses a single underwater hydrophone is proposed in this paper to solve problems of Long Baseline (LBL) array laying and communication synchronisation problems among all hydrophones in the traditional method. The proposed system comprises a Strapdown Inertial Navigation System (SINS), a single hydrophone installed at the bottom of the AUV and a single underwater sound source that emits signals periodically. A matrix of several virtual hydrophones is formed with the movement of the AUV. In every virtual LBL window, the time difference from the transmitted sound source to each virtual hydrophone is obtained by means of a Smooth Coherent Transformation (SCOT) weighting cross-correlation in the frequency domain. Then, the recent location of the AUV can be calculated. Simulation results indicate that the proposed method can effectively compensate for the position error of SINS. Thus, the positioning accuracy can be confined to 2 m, and the method achieves good applicability. Compared with traditional underwater acoustic positioning systems, the proposed method can provide great convenience in engineering implementation and can reduce costs.

Passive Acoustic Determination of Wave-Breaking Events and Their Severity across the Spectrum

2006 ◽  
Vol 23 (4) ◽  
pp. 599-618 ◽  
Author(s):  
Richard Manasseh ◽  
Alexander V. Babanin ◽  
Cameron Forbes ◽  
Kate Rickards ◽  
Irena Bobevski ◽  
...  
Keyword(s):  
Probability Distribution ◽  
Bubble Size ◽  
Wave Breaking ◽  
Bubble Formation ◽  
Acoustic Method ◽  
Breaking Waves ◽  
Sound Level ◽  
Real Field ◽  
Video Record ◽  
Passive Acoustic

Abstract A passive acoustic method of detecting breaking waves of different scales has been developed. The method also showed promise for measuring breaking severity. Sounds were measured by a subsurface hydrophone in various wind and wave states. A video record of the surface was made simultaneously. Individual sound pulses corresponding to the many individual bubble formations during wave-breaking events typically last only a few tens of milliseconds. Each time a sound-level threshold was exceeded, the acoustic signal was captured over a brief window typical of a bubble formation pulse, registering one count. Each pulse was also analyzed to determine the likely bubble size generating the pulse. Using the time series of counts and visual observations of the video record, the sound-level threshold that detected bubble formations at a rate optimally discriminating between breaking and nonbreaking waves was determined by a classification-accuracy analysis. This diagnosis of breaking waves was found to be approximately 70%–75% accurate once the optimum threshold had been determined. The method was then used for detailed analysis of wave-breaking properties across the spectrum. When applied to real field data, a breaking probability distribution could be obtained. This is the rate of occurrence of wave-breaking events at different wave scales. With support from a separate, laboratory experiment, the estimated bubble size is argued to be dependent on the severity of wave breaking and thus to provide information on the energy loss due to the breaking at the measured spectral frequencies. A combination of the breaking probability distribution and the bubble size could lead to direct estimates of spectral distribution of wave dissipation.

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