Sound Area Research Articles

Study on Motion Mechanism of Suspended Particles in Water Under Ultrasound

Particles in the ultrasonic field by the influence of acoustic radiation force, its motion characteristics will be changed. Based on the simplified ultrasonic cleaning assumption, numerical simulation is used to construct a simulation model of suspended particles in the ultrasonic field in liquid water environment, and to study the law of ultrasonic waves on the motion characteristics of suspended particles in water. The research results show that the ultrasonic arrangement of the array makes the ultrasonic waves produce ultrasonic focusing on the propagation path. The alternating fluctuations of ultrasonic positive and negative sound pressure are in the horizontal line parallel to the bottom, and the vibration amplitude of suspended particles in the middle region is the largest. For the vertical position perpendicular to the bottom, the region with larger vibration amplitude of suspended particles is at 1/5 from the bottom. The particles in the high sound pressure area are pushed to the gathering area, and the particle vibration amplitude in the low sound pressure area is small, which proves that the gathering area of the particles is often the low sound pressure area. The research results will contribute to the study of particle motion in the ultrasonic field.

Study on the Characteristics of Trackside Acoustic Flow Field of High-Speed Train under the Influence of Crosswind.

During the on-track acoustic detection process, a potential flow model and an acoustic finite element mathematical model based on synthetic wind are utilized, taking into account the combined effects of vehicle speed, wind direction angle, and crosswind speed. Simulation and modeling are achieved using Automatic Matching of Acoustic Radiation Boundary Conditions (AML) technology, enabling obtaining a distribution map and sound pressure frequency response curve of the trackside acoustic field under crosswind conditions by setting up field point grids. It is found that sound pressure values at the same location gradually increase as the vehicle speed increases in the frequency range of 10 Hz to 70 Hz, at different vehicle speeds. The sound pressure values and distribution area of the trackside acoustic field are the largest when the crosswind speed is 10 m/s (wind force at level five), allowing for easier location of the sound source when a fault occurs. The study also reveals that under different wind direction angles, the same location's sound pressure value on the trackside gradually decreases as the wind direction angle increases, to lower than that of the non-crosswind condition, severely hindering the reception and diagnosis of acoustic signals.

The apparent effusivity method for normalized thermal contrast evaluation in infrared thermographic testing

Thermographic nondestructive testing is used for the detection of near-surface discontinuities in materials, where indications of potential defects or discontinuities are detected and evaluated by their thermal contrast. The key requirements for successful thermographic data processing include managing non-uniform heating and identifying nominal areas. Advanced methods often rely on numerical simulation, which can be challenging and time-consuming. This study suggests a new simple method of thermal contrast calculation for flash-pulse thermography. It is based on the analysis of the inverse apparent effusivity. It includes an automated indication of the sound (defect-free) area and the creation of an artificial reference sequence, which is based on a temperature profile of the sound area and the non-uniform heating map. Derivative analysis of the smoothed contrast data is applied to improve detectability and Contrast/Noise Ratio (CNR). An experimental comparison of the proposed method with other known methods is presented. In the presented example, it allowed detection of 23 defects with an average CNR of 6.13 dB, against the traditional differential absolute contrast method, which detected only 13 defects with an average CNR of 0.53 dB. Thus, high detectability and high CNR values provided by the proposed method are demonstrated.

Design and Numerical Simulation of the Performance of Acoustic Plenum Chamber of a Marine Gas Turbine Air Supply System

In the present work, an approach to obtain a design method for the size of the plenum chamber cross-section of a marine gas turbine air supply system has been investigated. Flow in ducts makes noise which is very high in the turbine inlet part because of the large amount of flow. Therefore, this phenomenon should be considered in the design process. A suitable approach to design the duct is proposed (considering acoustic and aerodynamic performance at the same time). In this method, an air supply channel system of the marine gas turbine has been categorized into three sections according to the requirements of the aerodynamic and acoustic; inlet, plenum chamber, and outlet channels with circular cross-sections. The geometrical dimensions of inlet and outlet channels have been determined using the plane waves theory about a channel, in which the effects of flow is ignored. Space limitations of battleships at the dominant frequency have been considered. Then, the optimized size of the mid-channel section, in terms of both aerodynamic and acoustic requirements, using numerical methods and regarding the effects of flow has been calculated. Various 3D turbulent flows inside the plenum chamber have been considered, in which large eddy simulation turbulence model is utilized. Ffowcs, Williams and Hawkings models are used for the sound propagation process based on the Lighthill integral equation. The validity of the simulation has been checked by comparing results (sound pressure level) with experimental data obtained from a chamber. The comparison revealed the acceptable errors for a variety of frequencies. The results disclosed that the performance of channel system aerodynamic decreased when the fraction of plenum chamber cross-section to inlet/outlet channel cross-section increased. With an increase in the cross-section size at first Acoustic performance is improved and then worsen. Six different cases of marine gas turbine air supply system configurations have been presented, in which the limitation of the battleship space is considered. Examining and comparing the acoustic performance of different cases of the air supply channel system, it was found that the amount of sound pressure level, around the air supply channel system, and the high-pressure sound area can move along the air supply channel system. Additionally, deviations from plane waves considering the effects of flow have been inspected in all cases. The reason for this deviation is the effects of the airflow through the channel system and quadrupole sources in the production of sound in the channel system, which causes higher modes.

Quantification of the Effective Detectable Period for Concrete Voids of CLP by Lock-In Thermography

This study is to inspect the voids between the concrete containment building and the containment liner plate (CLP) in the light-water reactor type nuclear power plant with lock-in thermography (LIT) inspection technology. For that, a finite element method (FEM) model containing concrete voids was created, and the thermal distribution change of the CLP surface was simulated through numerical analysis simulation of various LIT inspection conditions and converted with real-time thermography data. For the simulated temperature distribution image and the amplitude and phase images calculated by the four-point method, the signal-to-noise ratio (SNR) is analyzed based on the sound area and void areas. As a result, the difference in SNR according to the size of voids was remarkable, and the effective detectable period (EDP), which was common to each inspection condition, was derived. Furthermore, a CLP concrete mockup identical to the model shape is produced, and the thermal image of the EDP is analyzed through the experiment with the same analysis technique, and the results are compared. Although there are some differences between the numerical analysis conditions and the experimental environments, the deduction and utilization of EDP through FEM simulation are considered useful approaches to applying LIT to inspect concrete voids on the back of the CLP.

Eastern High Arctic–Baffin Bay beluga whale (Delphinapterus leucas) estuary abundance and use from space

IntroductionThe Eastern High Arctic–Baffin Bay (EHA-BB) beluga whale (Delphinapterus leucas) population spends summer in estuaries around Somerset Island, Nunavut, Canada. A single abundance estimate from 1996 suggests an abundance >21,000 beluga whales; however, more information on abundance and distribution is needed to ensure effective management of this population, especially in estuaries where previous surveys provided minimal coverage. To assess the feasibility of using Very High Resolution (VHR) satellite imagery to obtain estuary abundance estimates for this beluga population, we evaluated a citizen science crowd counting initiative that was designed to monitor remote beluga whale populations and their estuary use.MethodsIn July and August 2020 the WorldView 2 and 3, and GeoEye 1 satellites were tasked to collect VHR imagery (30–41 cm) of estuaries previously known to be used by Eastern High Arctic–Baffin Bay beluga whales. The objectives were to obtain an estuary abundance estimate for this population from satellite imagery, and to evaluate the effectiveness of having imagery annotated using a crowd-source platform. Almost 3,800 km2of ocean imagery was analyzed using Maxar’s Geospatial Human Imagery Verification Effort (GeoHIVE) Crowdsourcing platform. Expert readers then manually compared counts to those performed by crowd-counters to determine variance in observer counts.Results and DiscussionThe estuary abundance estimate from 11 core estuaries was 12,128 (CV 36.76%, 95% confidence interval 6,036–24,368) beluga whales. This represents an estuary abundance estimate only, as the greater Peel Sound and Prince Regent Inlet areas were not photographed. The estuaries with the largest abundance of beluga whales were Creswell Bay, Maxwell Bay, and Prince Whales Island, with over 2,000 crowd-counted whales in each estuary. Although VHR imagery has potential to assist with surveying and monitoring marine mammals, for larger estuaries it was not always possible to photograph the entire area in a single day, and cloud cover was an issue for sections of most images. This work will assist with planning large-scale aerial surveys for monitoring beluga whale populations, identifying high-use areas and important beluga habitat, and highlights the utility of using VHR imagery to enhance our understanding of estuary abundance and distribution of Arctic whales.

Sound radiation attenuation by circular total-reflection elastic metasurface composed of subunits with cubic profiles

Utilizing metamaterials or acoustic black holes (ABHs) to control wave propagation and then to realize vibration control and sound radiation attenuation is a hot topic in recent years. However, using elastic metasurfaces that possess similar wave manipulation abilities with metamaterials and ABHs to attenuate sound radiation has not been reported yet. In this paper, a circular total-reflection elastic metasurface (CTREM) composed of subunits with cubic profiles similar with ABHs is proposed to realize vibration isolation and achieve broadband sound radiation attenuation of a plate below the cut-on frequency of the ABH. Compared with the corresponding bare plate and the plate containing a single ABH with a conventional design, the sound radiation efficiencies of the CTREM plate within and outside the vibration isolation band are both substantially attenuated. This phenomenon can be attributed to two distinct mechanisms: the total reflection of flexural waves caused by vibration isolation, and the local resonances of subunits. Analyses of the wavenumber spectra obtained from normal vibration velocities of the CTREM plate, both experimentally and numerically, along with the supersonic intensity patterns, reveal that the confined vibration energies are subsonic components localized within ineffective sound radiation areas. This, in turn, reduces the coupling strength of sound and vibration, thereby significantly attenuating sound radiation efficiency. The proposed CTREM provides a lossless and lightweight method for sound radiation attenuation.

The organic–inorganic hybrid sol for the consolidation of decayed wood in architectural heritage

Generally, the mechanical property defects and surface cracks are often presented in partly decayed wood components that are treated with silicon-based inorganic consilidants. To solve the problem, an organic–inorganic hybrid sol for the conservation of decayed wood was developed in this work, in which the polyvinyl alcohol (PVA) was introduced into the silicon inorganic sol formed by the sol–gel process of ethyl orthosilicate and methyl triethoxysilane. The properties of decayed wood treated with the organic–inorganic hybrid sol were characterized by performance tester, microcomputer control electron universal tester, simulation of swelling-shrinkage and thermal gravimetric analyzer. The consolidation mechanism was affirmed by scanning electron microscopy and Fourier transform infrared spectroscopy. The results revealed that the introduction of PVA into the hybrid sol led to a great improvement in comprehensive mechanical properties of the treated wood, accomplishing the swelling-shrinkage properties of the decayed area closer to those of sound area in wood. The improved properties could be ascribed to the hybrid gel coats formed on the surfaces of wood cells, which displayed a good performance in enhancing mechanical properties and thermostability. The hybrid sol can be used as a potential material to consolidate the partly decayed wood components for the protection of ancient wooden buildings.

Who Moved and Where Did They Go? An analysis of residential moving patterns in King County, WA between 2002–2017

From 2002-2017, moderate and middle socioeconomic status (SES) King County residents exhibited greater rates of moving compared to the lowest and highest SES residents. Geographically, movement rates were highest in East King County and North Seattle. High-SES residents were the least likely to move during all years. The percentage of King County residents in the high-SES group increased by 8.9 percentage points between 2002 and 2017, while the percentages of middle-, moderate- and lower-SES residents decreased (by 3.3, 3.2, and 2.4 percentage points, respectively). Neighborhoods in Seattle and East King County have seen the biggest percentage increases in high-SES residents from 2002 to 2017. Low-SES residents in all regions were the most likely to move out of the Puget Sound area. High-SES residents were most likely to move within their neighborhood.

Helmholtz resonator-based acoustic metamaterials enabling broadband asymmetric sound absorption and ventilation

Acoustic metamaterials with both ventilation and broadband asymmetric absorption have demonstrated great scientific significance and promising applicability. In this work, we design an asymmetric absorbing cell (AAC) consisting of a pair of detuned Helmholtz resonators (HRs) connected by sound channels that allows airflow with a ventilation ratio (ventilation area divided by sound incidence area) of 40%, which can achieve near-perfect sound absorption in the operating frequency range when sound waves are incident from the left port. However, when incident on the right port, the acoustic absorption coefficient does not exceed 40% at most, so asymmetric absorption is achieved. In addition, we form parallel three-cell asymmetric absorber (PTAA) by paralleling three AACs, which have broadband asymmetric absorption compared to AAC. Furthermore, we design multi-asymmetric absorber (MAA), which can achieve broadband asymmetric absorption range from 1000 Hz to 1750 Hz, and also allow air circulation. Moreover, experimental validation is conducted to demonstrate the effectiveness of fabricated MAA by 3D printing technology. Our designs open potential possibilities for developing ventilated functional devices capable of absorbing sound asymmetrically.

Proposal of a Simplified Tool for Early Acoustics Design Stage of Classrooms in Compliance with Speech Intelligibility Thresholds

The speech intelligibility properties of classrooms greatly influence the learning process of students. Proper acoustics can promote the inclusion of foreign students and children with learning or hearing impairments. While awareness of the topic is increasing, there is still no parameter that can describe all aspects of speech transmission inside a room. This complicates the design of classrooms and requires designers to have extensive knowledge of theory and experience. In the scientific and technical literature, there is a lack of predictive tools, easy to use by designers, which can guide the choices in the early design stages in order to move towards technical solutions able to ensure adequate levels of speech intelligibility. For this reason, in this paper, the most relevant speech intelligibility parameters found in the literature were collected and discussed. Among these, the Clarity index and Speech Transmission Index were singled out as the most effective ones, whose prediction can be made with relatively simple methods. They were then analyzed through their prediction formulas, and a tool was proposed to allow an easy estimation of the minimum total equivalent sound absorption area needed in a classroom. This tool greatly simplifies the early acoustics design stage, allowing the intelligibility of speech within a classroom to be increased without requiring much theoretical effort on the part of the designers.

Research on the Archaeoacoustic Simulation of Daxiong Main Halls in Chinese Buddhist Temples Through Comsol Tool

The acoustic analysis plays an irreplaceable role in obtaining information on Chinese Buddhist main halls tradition and relative practice that includes sound, deepening our comprehension of Chinese Buddhist architectural heritage. Various ceremonies and dojos constitute rich types of Buddhist main halls’ sound fields. In this paper, the indoor sound fields of four main halls in the Buddhist temples are researched and compared. This paper used Sketchup to build the models and simulate sound fields when conducting ceremonies and dojos using Comsol Multiphysics software. The four main halls are Chongshan temple main hall, Xiantong temple main hall, Shuxiang temple Manjusri hall and Bodhisattva Top main hall, which are located in separately four temples of Shanxi Wutai mountain in China. Targeting three acoustic parameters including the reverberation time(RT), the first ray arrival time(Re1first) and surface sound pressure level(SPL) distribution, we simulated the acoustic effect of the space occupancy, Buddha realm space and worship space, indicating that the acoustic wave diffusion rate was positively correlated with proportion of hall height to depth, while the first arrival time is exactly the opposite. The largest RT at 2000Hz(about 1.3s)in the shortest period for 500Hz voice was observed in the main hall of Pusa Peak, while T60 even reached 4s in Xiantong temple main hall. The acoustic wave transmission rate was positively correlated with proportion of hall’s height to depth, but the first ray arrival time was the opposite. The main hall of Pusa Peak had the shortest (0.0150s) first ray arrival time，the Shuxiang temple main hall had the longest time(0.0381s). In all the cases, appearing of the "sound shadow area" of the surface SPL distribution and the uneven sound energy distribution showed pillars in the middle space exerting significant impact on the acoustics of the Daxiong main hall.

Investigation of Spatial Coupling Coordination Development: Identifying Land System States from the Adaptation-Conflict Perspective.

With the advancement of global urbanization, ecosystem conservation and sustainable land development have become major issues. In this context, the uncoordinated and imbalanced development of the land-centered human-environment system requires urgent attention, especially in rust belt cities that pose critical challenges to regional land system sustainability. Therefore, taking Changchun City from 1990 to 2020 as an example, we identified and evaluated the ecosystem service (ES) balance and land use conflict from the perspectives of internal support and external development pressure. Based on the land system adaptation and conflict results, a coupling coordination degree model (CCDM) was constructed to investigate the spatio-temporal characteristics of land system development. The results indicated that there was an obvious downward trend in the regional ES balance, while areas with higher ES balance were mainly distributed in the eastern ecologically sound areas, and southern built-up areas presented deficient ES balance levels (i.e., demand exceeding supply), with a significant expansion trend from 1990 to 2020. Land use conflict was especially prominent in areas experiencing rapid rural-urban transformation, and the hot spots expanded noticeably. The spatio-temporal differences in the coupling coordination degree of ES balance and land use conflict were significant, whereas the land system of the study area has always been dominated by a balanced development pattern throughout the research period, except for the urban center, which tended to be in a stage of uncoordinated development, with the ES balance blocked. These findings suggest that it is necessary to coordinate urban and adjacent regions through regionally integrated efforts to alleviate the ES imbalance. This research can provide a scientific reference for analyzing regional land system states, coordinating the sustainable spatial development of ecosystems, and implementing revitalization strategies to achieve win-win land system goals.

Research on the detection of early caries based on hyperspectral imaging

Objective: We applied hyperspectral imaging (HSI) system to distinguish early caries from sound and pigmented areas. It will provide a theoretical basis and technical support, for research and development of an instrument that could be used for screening and detection of early dental caries. Methods: Eighteen extracted human teeth (molars and premolars), with varying degrees of natural pathology and no degree of decay involving dentin were obtained. HSI system with a wavelength range from 400 to 1000[Formula: see text]nm was used to obtain images of all 18 teeth containing sound, carious and pigmented areas. We compared the spectra of the wavebands at both 500[Formula: see text]nm and 780[Formula: see text]nm from the different tooth states, and the reflectance difference between sound versus carious lesions and sound versus pigmented areas, respectively. Results: There was a slight difference in reflectance between carious areas and pigmented areas at 500[Formula: see text]nm. A substantial difference was additionally noted in reflectance between carious areas and pigmented areas at 780[Formula: see text]nm. Conclusion: The results have shown that the interference of tooth surface pigment can be eliminated in the near-infrared (NIR) waveband, and the caries can be effectively identified from the pigmented areas. Thus, it could be used to detect carious areas of teeth in place of the traditional visual inspection method or white light endoscopy. Clinical significance: The NIR diffused light signal enables the identification of early caries from pigment and other interference, providing a reasonable detection tool for early detection and early treatment of teeth diseases.

Automated detection and quantification of the onset of undercoating corrosion using pulsed thermography

AbstractCorrosion of metals can occur under coatings making early visual detection almost impossible which enables corrosion to progress undetected. Nondestructive evaluation can be used to inspect parts during their life. Thermography uses the difference in thermal properties between defective and sound areas to locate defects by applying a short pulse of heat and monitoring the surface temperature of the sample with an infrared camera. However, currently, inspection is reliant on highly trained operators to analyze images for defects and in the case of corrosion, judge its growth. The aim of this research was to develop and test a novel algorithm to identify and quantify the onset of corrosion under coatings and monitor the growth. Using this algorithm, the corrosion was autonomously detected in a variety of mild steel samples exposed to three different corrosive environments. The method successfully detected, quantified, and monitored the growth of corrosion under coatings accurately and robustly using thermal images gathered by a microbolometer infrared camera. The extent of corrosion was reported with an accuracy of 3% absolute error when compared to the true extent.

Genetic Testing Among Patients with High-Risk Breast, Ovarian, Pancreatic, and Prostate Cancers.

The National Comprehensive Cancer Network recommends genetic testing in patients with potentially hereditary breast, ovarian, pancreatic, and prostate cancers (HBOPP). Knowledge of genetic mutations impacts decisions about screening and treatment. A retrospective cohort study of 28,586 HBOPP patients diagnosed from 2013 to 2019 was conducted using a linked administrative-cancer database in the Seattle-Puget Sound SEER area. Guideline-concordant testing (GCT) was assessed annually according to guideline updates. Frequency of testing according to patient/cancer characteristics was evaluated using chi-squared tests, and factors associated with receipt of genetic testing were identified using multivariable logistic regression. Testing occurred in 17% of HBOPP patients, increasing from 9% in 2013 to 21% in 2019 (p < 0.001). Ovarian cancer had the highest testing (40%) and prostate cancer the lowest (4%). Age < 50, female sex, non-Hispanic White race, commercial insurance, urban location, family history of HBOPP, and triple negative breast cancer (TNBC) were associated with increased testing (all p < 0.05). GCT increased from 38% in 2013 to 44% in 2019, and was highest for early age at breast cancer diagnosis, TNBC, male breast cancer, and breast cancer with family history of HBOPP (all > 70% in 2019), and lowest for metastatic prostate cancer (6%). The frequency of genetic testing for HBOPP cancer has increased over time. Though GCT is high for breast cancer, there are gaps in concordance among patients with other cancers. Increasing provider and patient education, genetic counseling, and insurance coverage for testing among HBOPP patients may improve guideline adherence.

OneBusAway Multi-Region – Rapidly Expanding Mobile Transit Apps to New Cities

Real-time transit information offers many benefits to transit riders, including reduced wait times and increased customer satisfaction. However, offering real-time transit services has been challenging for many transit agencies. While mobile applications (apps) have emerged as a preferred dissemination method for real-time information, it is typically cost-prohibitive for transit agencies to fund custom development of native mobile apps for all popular smartphone platforms. Third-party developers can offer services if an agency openly shares real-time data, but these individuals are volunteers whose priorities and deadlines may not be the same as the agency’s. As a result, few cities have full app portfolios that cover all smartphone platforms. This paper presents the OneBusAway multi-region project, a collaborative effort that is enabling the rapid expansion of native mobile transit apps to new cities. OneBusAway is an open-source transit information system that has provided real-time transit services to the Puget Sound (Washington) area since 2008. The new OneBusAway multi-region feature expands the coverage of the existing Android, iPhone, Windows Phone, and Windows 8 apps for OneBusAway to new cities, including Tampa and Atlanta. The multi-region system architecture, collaborative design and development process, and lessons learned from this ground-breaking project are discussed. The fundamental shift from proprietary to open-source software in the transit industry that has made this type of project possible also is examined.

Analysis of aerodynamic and aeroacoustics of full scale landing gear

The aerodynamic noise of a landing gear is an important source of airframe noise. The analysis of its noise characteristics plays an important role in the design of a low-noise landing gear. Based on the FL-52 acoustic wind tunnel test technology, the coupled scale adaptive model and the acoustic disturbance equation, the results on aerodynamic noise of a full-scale landing gear model are analyzed. The high-fidelity model includes transverse strut, torsion arm, piston rod, wheel and other parts. The characteristics of static pressure distribution, power spectrum density of pulsating pressure, aerodynamic noise source distribution and directivity of overall sound pressure level are analyzed. The noise characteristics of the far-field microphone are compared with the local microphone installed in the wheel cavity. In this way, we characterize the directivity of pure tone in the wheel cavity and understand its contribution to the far-field noise. The results show that the aerodynamic noise of the landing gear can be quantified accurately by the hybrid numerical method. The pure tone has two frequencies inside and outside the wheel of the landing gear: 560 Hz and 960 Hz. The peak of the loudest sound pressure level reaches 136 dB, and the pure tone radiates to the surface of the non-separation area of the wheel of the landing gear. However, the wall pressure spectrum of the points located in the turbulence region shows a wide-frequency characteristic, and there is no obvious pure tone. From the point of view of the far-field noise directivity, the forward noise of the landing gear is larger than the rear noise, and there is a small overall sound pressure level area at the points of 65 and 110 degrees respectively. When the monitoring points are far away, the far-field noise of the landing gear shows the characteristics of wide frequency, and no obvious pure tone appears. The method can provide the technical support for predicting the aeroacoustics of a landing gear and designing a low-noise land gear.

Measuring Spatial Associations between Environmental Health and Beliefs about Environmental Governance.

Research has shown an increasing trend in attempts to integrate social and ecological data that use indicators to improve quality of life. This includes understanding people's beliefs about environmental governance. Understanding patterns in beliefs of environmental governance can be a powerful way to help policy makers take informed actions that meet individuals' needs and expectations. This study examines connections between spatial patterns of beliefs about environmental governance and the health of the environment where people live, measured from both a public health and ecological perspective. Data on people's beliefs about environmental governance were collected in the Puget Sound area of Washington state. Environmental health data include environmental public health disparities including effects and exposures, bird diversity, and tree cover. Results indicate local scale heterogeneity exists within the Puget Sound region. Using AIC model selection, there was strong evidence for effects of canopy cover, environmental effects and exposures, and years of residency, and moderate to strong evidence for the effects on beliefs about environmental governance of race and sex. There was little support for effects of political ideology, income, age, education, or bird diversity. The Akaike Information Criteria (AIC) top model included a negative effect of canopy cover, years of residency, race (i.e., of being non-white), and sex (i.e., of being male), and a positive effect of environmental effects and of environmental exposures. Relating data on environmental health and beliefs about environmental governance generates a more nuanced understanding of determinants of environmental governance success and public support.

Assessing the effect of human activities on biophony in urban forests using an automated acoustic scene classification model

Monitoring biodiversity and assessing the impact of human activities using acoustics is a promising area in the field of urban ecology. Previous studies on urban biodiversity using acoustics are often limited by data continuity and survey scope, making it difficult to answer questions about relationships between bird population dynamics and environmental factors. To some extent, big data methods such as continuous acoustic monitoring have bridged this gap and provided new research paths to address the problem. In this study, we proposed a machine learning (ML) method that uses convolutional neural networks (CNN) and target sound area ratios (TSAR) to quantify the dominance of seven types of acoustic scenes. Acoustic data was recorded at nine sites in three urban forests in Guangzhou, China. Using the site-related sound data, we trained the convolutional neural network and identified seven target soundscape components with an overall F1 score of 0.97, a precision of 0.96, and a recall of 0.97. Spatial patterns of acoustic scenes in urban forests were examined to understand the effective working radius of monitoring equipment and the impacts of differing land use types on the composition of soundscapes. This study indicates significant interactions between human activities and biodiversity using acoustics, demonstrates that vocal organisms respond to environmental changes primarily by changes in their vocal frequencies, and proposes a novel framework for utilizing acoustics to monitor urban biodiversity. Going forth, these analyses help to promote the conservation of biodiversity and the sustainability of urban development.