Acoustic Monitoring Technology Research Articles

VGGish-based detection of biological sound components and their spatio-temporal variations in a subtropical forest in eastern China.

Passive acoustic monitoring technology is widely used to monitor the diversity of vocal animals, but the question of how to quickly extract effective sound patterns remains a challenge due to the difficulty of distinguishing biological sounds within multiple sound sources in a soundscape. In this study, we address the potential application of the VGGish model, pre-trained on Google's AudioSet dataset, for the extraction of acoustic features, together with an unsupervised clustering method based on the Gaussian mixture model, to identify various sound sources from a soundscape of a subtropical forest in China. The results show that different biotic and abiotic components can be distinguished from various confounding sound sources. Birds and insects were the two primary biophony sound sources, and their sounds displayed distinct temporal patterns across both diurnal and monthly time frames and distinct spatial patterns in the landscape. Using the clustering and modeling method of the general sound feature set, we quickly depicted the soundscape in a subtropical forest ecosystem, which could be used to track dynamic changes in the acoustic environment and provide help for biodiversity and ecological environment monitoring.

Evolution of acoustic methods for assessing and managing exposure of gray whales to sound pulses from seismic surveys off Sakhalin Island, Russian Far East

An effective program of estimation and mitigation of sound exposure from airgun array pulses is of vital importance when an endangered whale population forages in coastal waters near oil and gas production fields, where geophysical exploration campaigns regularly take place. Starting in 2001, increasingly sophisticated acoustic measurement and modeling techniques have been used for the environmental management of airgun array seismic surveys adjacent to the nearshore feeding grounds of the gray whale (Eschrichtius robustus) off the NE coast of Sakhalin Island, Russia. These monitoring data are also used in combination with visual observations for the analysis of the effects of sound exposure on whale behavior, distribution, and energetics. This talk follows two decades of evolution of the acoustic monitoring technology used in the Sakhalin studies, from rudimentary analog sonobuoys with limited bandwidth VHF telemetry, to digital stations capable of onboard signal processing and relaying of data via satellite to anywhere on the globe. In parallel, it traces the advancement of modeling techniques capable to fill the gaps between sparse measurement locations to yield high resolution estimates of the sound field from seismic sources operating concurrently at different, moving locations and in various regimes of ramp-up, production, or mitigation pulses.

Acoustic Characterization around the CalWave Wave Energy Converter

Sound generated by marine energy (ME) installations in the ocean environment remains a particular concern for environmental permitting despite the limited evidence showing low levels of ME sounds relative to other anthropogenic sounds. In an effort to increase understanding of potential environmental effects of marine energy projects and help reduce barriers to marine energy deployments, a new acoustic monitoring technology, the NoiseSpotter®, was developed and recently demonstrated around CalWave’s operational scaled xWave™ wave energy converter (WEC). The NoiseSpotter® improves upon traditional acoustic sensing techniques by use of a cost-effective, compact array of acoustic particle velocity sensors that characterizes, classifies, and provides accurate location information for anthropogenic and natural sounds in real time. Results are presented from co-deployments of NoiseSpotter® with the operational CalWave WEC that were conducted over a 9-day period in fall 2021 offshore of Scripps Research Pier in San Diego, California, USA. The multi-day deployment of the NoiseSpotter® at 100 m from the CalWave WEC revealed a rich library of sounds that include: Low-level (~95 dB re 1 µPa relative to an ambient noise floor between 80-90 dB re 1 µPa) sounds from the WEC associated with the deliberate actuation of mechanical components, Sounds from a hovering helicopter, Marine mammal vocalizations, and, Small boat engines. Sound levels from the WEC were placed within the context of ambient sounds, and reveal little deviation from the ambient soundscape. The azimuthal anisotropy of WEC sound was investigated via deployments along four cardinal directions around the WEC. While a noticeable increase was observed along the north-south orientation, the sound levels along all directions still showed little deviation relative to the ambient noise floor. Analysis of low-level WEC sounds in conjunction with exploratory machine learning techniques demonstrate the utility of directional acoustic sensing in distinguishing marine energy sounds from the myriad other sounds in the surrounding ocean environment.

Study on feeding behavior and biological sound of Sebastes schlegelii

The construction of marine ranches can enrich and conserve the fishery resources and improve the marine ecosystem, which helps realize the sustainable utilization of these resources. Sebastes schlegelii is a major breeding and releasing fish species in the marine ranches of North China. Its behavioral characteristics can be understood better by researching its vocalization, which will provide data support for constructing acoustic taming marine ranches with S. schlegelii as the target fish species. However, there are few studies focusing on its sounds and behaviors. Therefore, based on the passive acoustic monitoring technology, the audios of underwater noises made by S. schlegelii were extracted using an AQH hydrophone. The high-definition internet protocol camera was used to monitor the behavior change of S. schlegelii. Then, by collating and replaying the collected audios and videos, the feeding behavior and biological noises of S. schlegelii were matched to analyze their relationship. Results are as follows: (1) The noise of chewing settling granular baits (Φ5.0 mm) has a main frequency band and sound pressure level of 2000~4500 Hz and 96.53 ± 0.65 dB, respectively; in this feeding process, the main frequency band and sound pressure level of the swimming noise are 25~400 Hz and 95.63 ± 0.38 dB, respectively; the values are 500~700 Hz and 97.34 ± 4.91 dB, respectively, for the noise of flapping the water with the tail. (2) The sound signals emitted by S. schlegelii are mostly presented as single pulses during normal habitation or ingestion of baits on the surface of the water tank. However, S. schlegelii will attack and fight against each other when scrambling for baits, during which these signals are presented as continuous pulses. To sum up, the vocalization of S. schlegelii is closely related to feeding activities, and the sounds produced under different behaviors have specific biological significance.

Syllable clustering analysis-based passive acoustic monitoring technology and its application in bird monitoring

Syllable clustering analysis-based passive acoustic monitoring technology and its application in bird monitoring

The dynamical complexity of seasonal soundscapes is governed by fish chorusing

Passive acoustic monitoring technology can depict underwater soundscapes, yet phenological and seasonal patterns and shifts in soundscapes are still poorly understood. Here we analyse the seasonal soundscape in the Eastern Taiwan Strait in 2017 using nonlinear dynamical complexity modelling. We find an annual phenology of fish chorusing that begins in spring, and peaks in summer before beginning to subside in autumn and becoming silent in winter. During spring and summer, the soundscape exhibited significantly higher complexity and predictability than in autumn and winter, due to the presence of regular fish chorusing. Soundscape dynamics shifted from being nonlinear in spring and summer to being linear and stochastic in autumn and winter. Our findings suggest that soundscapes could be used to measure phenological patterns and seasonal shifts in marine species behaviour. We propose that monitoring soundscapes could help assess the long-term health of marine ecosystems under environmental and climatic change.

Making a science out of preanalytics: An analytical method to determine optimal tissue fixation in real-time.

Modern histopathology is built on the cornerstone principle of tissue fixation, however there are currently no analytical methods of detecting fixation and as a result, in clinical practice fixation is highly variable and a persistent source of error. We have previously shown that immersion in cold formalin followed by heated formalin is beneficial for preservation of histomorphology and have combined two-temperature fixation with ultra-sensitive acoustic monitoring technology that can actively detect formalin diffusing into a tissue. Here we expand on our previous work by developing a predictive statistical model to determine when a tissue is properly diffused based on the real-time acoustic signal. We trained the model based on the morphology and characteristic diffusion curves of 30 tonsil cores. To test our model, a set of 87 different tonsil samples were fixed with four different protocols: dynamic fixation according to our predictive algorithm (C/H:Dynamic, N = 18), gold-standard 24 hour room temperature (RT:24hr, N = 24), 6 hours in cold formalin followed by 1 hour in heated formalin (C/H:6+1, N = 21), and 2 hours in cold formalin followed by 1 hour in heated formalin (C/H:2+1, N = 24). Digital pathology analysis revealed that the C/H:Dynamic samples had FOXP3 staining that was spatially uniform and statistically equivalent to RT:24hr and C/H:6+1 fixation protocols. For comparison, the intentionally underfixed C/H:2+1 samples had significantly suppressed FOXP3 staining (p<0.002). Furthermore, our dynamic fixation protocol produced bcl-2 staining concordant with standard fixation techniques. The dynamically fixed samples were on average only submerged in cold formalin for 4.2 hours, representing a significant workflow improvement. We have successfully demonstrated a first-of-its-kind analytical method to assess the quality of fixation in real-time and have confirmed its performance with quantitative analysis of downstream staining. This innovative technology could be used to ensure high-quality and standardized staining as part of an expedited and fully documented preanalytical workflow.

What's the Buzz About? Progress and Potential of Acoustic Monitoring Technologies for Investigating Bumble Bees

Pollination is a vital ecosystem service for both natural and agricultural ecosystems. Most flowering plants-including many staples in the human diet such as fruits, vegetables and nuts- require animals for pollination. The majority is done by over 20,000 species of bees, some of which are managed commercially to provide these services. The global industry of pollination is valued at US $153 billion annually and is increasing in demand to meet the needs of a growing human population [1]. However, both managed and wild bees, especially the ecologically and economically important bumble bees (Bombus spp.), are suffering alarming declines worldwide, presenting serious implications for food security and biodiversity. Despite numerous pleas by farmers and scientists for improved management and monitoring methods [2], [3], precision techniques for these essential pollinators are still lacking.

Clearing a Path to Commercialization of Marine Renewable Energy Technologies Through Public–Private Collaboration

Governments are increasingly turning toward public–private partnerships to bring industry support to improving public assets or services. Here, we describe a unique public–private collaboration where a government entity has developed mechanisms to support public and private sector advancement and commercialization of monitoring technologies for marine renewable energy. These support mechanisms include access to a range of skilled personnel and test facilities that promote rapid innovation, prove reliability, and inspire creativity in technology development as innovations move from concept to practice. The ability to iteratively test hardware and software components, sensors, and systems can accelerate adoption of new methods and instrumentation designs. As a case study, we present the development of passive acoustic monitoring technologies customized for operation in energetic waves and currents. We discuss the value of testing different systems together, under the same conditions, as well as the progression through different test locations. The outcome is multiple, complementary monitoring technologies that are well suited to addressing an area of high environmental uncertainty and reducing barriers to responsible deployment of low-carbon energy conversion systems, creating solutions for the future.

Application of passive acoustic monitoring technology in the monitoring of western black crested gibbons

Application of passive acoustic monitoring technology in the monitoring of western black crested gibbons

A new reliable acoustic respiratory monitoring technology during upper gastrointestinal tract therapeutic endoscopy with CO2 insufflation.

Previous studies documented the effectiveness and benefits of capnography monitoring during propofol-based sedation for colonoscopy to reduce the incidence of hypoxemia. However, the performance of capnography during longer duration endoscopic therapy of upper gastrointestinal tract cancers under CO2 insufflation it is not well known. In this study, we compare a new device with acoustic monitoring technology to standard capnography monitoring. We retrospectively analyzed 49 patients who underwent endoscopic resection of early upper gastrointestinal tract cancer between December 2013 and October 2014. All 49 patients were monitored using both acoustic monitoring technology and standard capnography. We investigated the duration of the periods with unmeasurable respiratory rate during the overall procedure. When comparing standard capnography monitoring to the new acoustic monitoring technology, the ratio of the unmeasurable time was significantly lower in RRa (36.9% vs. 21.6%, p < 0.01). The ratio of unmeasurable respiratory rate by capnography was strongly correlated to the ratio of unmeasurable PETCO2 level by capnography (R2 = 0.847). There were no severe events or adverse events (grade 2 or more) during all 49 procedures. The acoustic monitoring technology provides a more reliable respiratory monitoring when compared to standard capnography during endoscopic resection of upper gastrointestinal tract cancers under CO2 insufflation, even if the procedures were prolonged and complex.

Deploying Acoustic Detection Algorithms on Low-Cost, Open-Source Acoustic Sensors for Environmental Monitoring.

Conservation researchers require low-cost access to acoustic monitoring technology. However, affordable tools are often constrained to short-term studies due to high energy consumption and limited storage. To enable long-term monitoring, energy and space efficiency must be improved on such tools. This paper describes the development and deployment of three acoustic detection algorithms that reduce the power and storage requirements of acoustic monitoring on affordable, open-source hardware. The algorithms aim to detect bat echolocation, to search for evidence of an endangered cicada species, and also to collect evidence of poaching in a protected nature reserve. The algorithms are designed to run on AudioMoth: a low-cost, open-source acoustic monitoring device, developed by the authors and widely adopted by the conservation community. Each algorithm addresses a detection task of increasing complexity, implementing extra analytical steps to account for environmental conditions such as wind, analysing samples multiple times to prevent missed events, and incorporating a hidden Markov model for sample classification in both the time and frequency domain. For each algorithm, we report on real-world deployments carried out with partner organisations and also benchmark the hidden Markov model against a convolutional neural network, a deep-learning technique commonly used for acoustics. The deployments demonstrate how acoustic detection algorithms extend the use of low-cost, open-source hardware and facilitate a new avenue for conservation researchers to perform large-scale monitoring.

The Office of Naval Research Marine Mammal Program, 1990–2006

ONR first stood up a dedicated marine mammal research program in 1990. The initial effort was led by Dan Costa, with the support of experienced ONR program leaders like Mel Briscoe, Bernie Zahuranec, and Steve Zornetzer. The author was privileged to manage the program from 1993 to 2006; a period of rapid expansion of concern about the marine environment accompanied by the desire to put tools for improved understanding in the hands of scientists and decision makers. The emphasis from the start was on multi-disciplinary collaborations. Major research themes included hearing and exploration of Temporary Threshold Shift as a metric of auditory risk; advancement of animal-borne scientific instruments (“tags“); advancement of ocean acoustic monitoring technologies, refinement of field sound exposure experimental methods, and improvement of sound exposure models. Frequent external reviews, including four National Research Council (NRC) reviews, were vital to the quality and credibility of the program. The 2005 NRC review on the Population Consequences of Acoustic Disturbance (PCAD) is a textbook example of how ONR's basic research contributions have had far-reaching consequences that greatly exceeded initial expectations. The convergence of growing concern about manmade sound in the ocean and the ONR model for quality in basic research has had a profound impact on our ability to understand ocean bioacoustics and to make better informed decisions about the potential risks posed by human activities in the marine environment.

Collaborative Exploration and Sensemaking of Big Environmental Sound Data

Many ecologists are using acoustic monitoring to study animals and the health of ecosystems. Technological advances mean acoustic recording of nature can now be done at a relatively low cost, with minimal disturbance, and over long periods of time. Vast amounts of data are gathered yielding environmental soundscapes which requires new forms of visualization and interpretation of the data. Recently a novel visualization technique has been designed that represents soundscapes using dense visual summaries of acoustic patterns. However, little is known about how this visualization tool can be employed to make sense of soundscapes. Understanding how the technique can be best used and developed requires collaboration between interface, algorithm designers and ecologists. We empirically investigated the practices and needs of ecologists using acoustic monitoring technologies. In particular, we investigated the use of the soundscape visualization tool by teams of ecologists researching endangered species detection, species behaviour, and monitoring of ecological areas using long duration audio recordings. Our findings highlight the opportunities and challenges that ecologists face in making sense of large acoustic datasets through patterns of acoustic events. We reveal the characteristic processes for collaboratively generating situated accounts of natural places from soundscapes using visualization. We also discuss the biases inherent in the approach. Big data from nature has different characteristics from social and informational data sources that comprise much of the World Wide Web. We conclude with design implications for visual interfaces to facilitate collaborative exploration and discovery through soundscapes.

Automated detection of low-frequency rumbles of forest elephants: A critical tool for their conservation.

African forest elephants (Loxodonta cyclotis) occupy large ranges in dense tropical forests and often use far-reaching vocal signals to coordinate social behavior. Elephant populations in Central Africa are in crisis, having declined by more than 60% in the last decade. Methods currently used to monitor these populations are expensive and time-intensive, though acoustic monitoring technology may offer an effective alternative if signals of interest can be efficiently extracted from the sound stream. This paper proposes an automated elephant call detection algorithm that was tested on nearly 4000 h of field recordings collected from five forest clearings in Central Africa, including sites both inside protected areas and in logging concessions. Recordings were obtained in different seasons, years, and under diverse weather conditions. The detector achieved an 83.2% true positive rate when the false positive rate is 5.5% (approximately 20 false positives per hour). These results suggest that this algorithm can enable analysis of long-term recording datasets or facilitate near-real-time monitoring of elephants in a wide range of settings and conditions.

Continuous surveillance of oxygen saturation and respirations after bariatric surgery

Background: Continuous, post-operative patient monitoring can provide healthcare workers with earlier warning signs of patient deterioration. The Masimo Pulse CO-Oximeter (Masimo Corporation, Irvine, CA) has acoustic monitoring technology which measures respiratory rate (RR) by analyzing acoustic signals generated across the upper airway while breathing. We continuously monitored for 19-24 hours (hrs) post-surgery RR and oxygen saturation (SpO2) in obese patients who underwent laparoscopic Roux-en-Y gastric bypass (RYGB) for bariatric surgery weight loss. The objective was to assess incidence of decreased RR ( 30, between 30 and 10, and < 10 breaths per minute). The percentage of time that the patient spent in each range was calculated. Median values were calculated for each category. Results: During the extended monitoring period, the median percentage of time spent with SpO2 below 90% was 5.4%. The median percentage of time that a subject had a RR of less than 10 respirations/min was 0%. There was no correlation between SpO2 and respiratory rate. Fourteen patients in our study population were on continuous positive airway pressure (CPAP) and reported VAS scores between 3 and 6. This may have prevented them from being deeply sedated. There were no apnea periods longer than 30 seconds. Conclusions: In this small group of obese patients, a low RR was not encountered during an extended post-operative period. These patients did not experience desaturation, apnea, or significant reductions of RR.

Technology Focus: Production and Facilities (December 2015)

Technology Focus Advances in technologies for production and facilities are being driven by the development of unconventional resources and the need for more-efficient and -reliable operations. Considerable progress is being made, for example, on the design and performance of wellbore-inflow-control devices. The objective of this technology is to control both the volume and the character of fluids entering an extended-length wellbore. Both passive and autonomous devices are now available from a number of suppliers. Field experience with this technology was the subject of 10% of the papers in this year’s survey of publications and presentations. Pipeline technology continues its rapid evolution with a focus on the safe operation of, and the early detection of breaks and leaks in, long-distance lines. The environmental hazards associated with unplanned fluid losses from material failures or unwelcome human intervention make the deployment of acoustic monitoring technologies increasingly desirable and economically viable. In some geographical areas, strong environmental and safety concerns about pipelines will most likely favor the installation of such technologies on any line passing through urban or other sensitive environments. With low oil and gas prices being a continuing drag on our industry, a significant amount of work was reported on field-optimization and operations-improvement (i.e., cost-reduction) technology. Authors worldwide described their efforts to reduce unplanned shutdowns, lower maintenance costs, improve operational reliability, and squeeze more barrels out of existing wells by developing field-optimization models. One interesting development associated with production optimization is the use of nanotechnologies to address issues ranging from the control of rock wettability characteristics to the development of fluids with improved heat-transfer characteristics. These applications are moving the field of nanomaterials from the character of “science projects” to emerging or commercial technologies. Finally, the trend toward the increased use of modeling and simulation technologies, which was identified in this feature last year, continues unabated. More than 25% of the papers reviewed for this year’s feature were concerned with the development of models and simulations or were associated with their use and validation. The emphasis was heavy on the generation of models and simulations that were simple to use, were computationally efficient, and that generated short-term realizable cost savings. One interesting paper described the development of a “fuzzynistic” model for more accurate predictions of flow patterns and pressure losses in pipelines, a critical topic for the design and operational control of surface facilities. JPT Recommended additional reading at OnePetro: www.onepetro.org. IPTC 17977 Performance of Autonomous- Inflow-Control Completion in Heavy-Oil Reservoirs by Eltazy Eltaher, Heriot-Watt University, et al. SPE 174812 Fuzzynistic Models for Multiphase-Flow-Pattern Identification by Florentina Popa, Halliburton, et al. SPE 174746 CFD Study for Heat Transfer and Flow Characteristics of Nanofluid in a Flat-Tube Heat Exchanger by Mohamed Elsebay, Gempetco, et al.

Linking ecological condition and the soundscape in fragmented Australian forests

Natural landscapes are increasingly subjected to anthropogenic pressure and fragmentation resulting in reduced ecological condition. In this study we examined the relationship between ecological condition and the soundscape in fragmented forest remnants of south-east Queensland, Australia. The region is noted for its high biodiversity value and increased pressure associated with habitat fragmentation and urbanisation. Ten sites defined by a distinct open eucalypt forest community dominated by spotted gum (Corymbia citriodora ssp. variegata) were stratified based on patch size and patch connectivity. Each site underwent a series of detailed vegetation condition and landscape assessments, together with bird surveys and acoustic analysis using relative soundscape power. Univariate and multivariate analyses indicated that the measurement of relative soundscape power reflects ecological condition and bird species richness, and is dependent on the extent of landscape fragmentation. We conclude that acoustic monitoring technologies provide a cost effective tool for measuring ecological condition, especially in conjunction with established field observations and recordings.

The Accuracy, Precision and Reliability of Measuring Ventilatory Rate and Detecting Ventilatory Pause by Rainbow Acoustic Monitoring and Capnometry

Current methods for monitoring ventilatory rate have limitations including poor accuracy and precision and low patient tolerance. In this study, we evaluated a new acoustic ventilatory rate monitoring technology for accuracy, precision, reliability, and the ability to detect pauses in ventilation, relative to capnometry and a reference method in postsurgical patients. Adult patients presenting to the postanesthesia care unit were connected to a Pulse CO-Oximeter with acoustic monitoring technology (Rad-87, version 7804, Masimo, Irvine, CA) through an adhesive bioacoustic sensor (RAS-125, rev C) applied to the neck. Each subject also wore a nasal cannula connected to a bedside capnometer (Capnostream20, version 4.5, Oridion, Needham, MA). The acoustic monitor and capnometer were connected to a computer for continuous acoustic and expiratory carbon dioxide waveform recordings. Recordings were retrospectively analyzed by a trained technician in a setting that allowed for the simultaneous viewing of both waveforms while listening to the breathing sounds from the acoustic signal to determine inspiration and expiration reference markers within the ventilatory cycle without using the acoustic monitor- or capnometer-calculated ventilatory rate. This allowed the automatic calculation of a reference ventilatory rate for each device through a software program (TagEditor, Masimo). Accuracy (relative to the respective reference) and precision of each device were estimated and compared with each other. Sensitivity for detection of pauses in ventilation, defined as no inspiration or expiration activity in the reference ventilatory cycle for ≥30 seconds, was also determined. The devices were also evaluated for their reliability, i.e., the percentage of the time when each displayed a value and did not drop a measurement. Thirty-three adults (73% female) with age of 45 ± 14 years and weight 117 ± 42 kg were enrolled. A total of 3712 minutes of monitoring time (average 112 minutes per subject) were analyzed across the 2 devices, reference ventilatory rates ranged from 1.9 to 49.1 bpm. Acoustic monitoring showed significantly greater accuracy (P = 0.0056) and precision (P- = 0.0024) for respiratory rate as compared with capnometry. On average, both devices displayed data over 97% of the monitored time. The (0.95, 0.95) lower tolerance limits for the acoustic monitor and capnometer were 94% and 84%, respectively. Acoustic monitoring was marginally more sensitive (P = 0.0461) to pauses in ventilation (81% vs 62%) in 21 apneic events. In this study of a population of postsurgical patients, the acoustic monitor and capnometer both reliably monitored ventilatory rate. The acoustic monitor was statistically more accurate and more precise than the capnometer, but differences in performance were modest. It is not known whether the observed differences are clinically significant. The acoustic monitor was more sensitive to detecting pauses in ventilation. Acoustic monitoring may provide an effective and convenient means of monitoring ventilatory rate in postsurgical patients.

Expansion of Existing Monitoring System on Great Man-Made River Project Using Acoustic Fibre Optic Technology

Acoustic monitoring has played a major role in the management of one of the world's largest civil engineering projects. After experiencing failures on their pipeline between 1999 and 2001, the Great Man-Made River Authority (GMRA) undertook an aggressive condition assessment program. This program led to the development of a comprehensive Pipeline Risk Management System (PRMS), making the Great Man-Made River Project one of the best managed pipelines in the world. The planned expansion of the existing acoustic monitoring system, a key component of the PRMS, will allow for monitoring of over 700km of pipeline. This paper will discuss steps taken to-date, the acoustic monitoring technology and the expansion of this key component to the management strategy for the pipeline.